| Revista de materiale plasice |
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Acoperiri poliuretanice pentru protectia aniticorosiva
STELIAN VLAD
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| In this study a series of urethane prepolymers based on diisocyanates (diphenylmethane diisocyanate MDI, toluene diisocyanate TDI), castor-oil and filler from bronze aluminum and bitumen in methylene chloride as solvent was synthesized for corrosive |
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Acoperiri organice pe baza de vopsele pulbere
IX. Influenta agentilor de texturare asupra caracteristicilor vopselelor pulbere epoxi-poliesterice
Carmen Elena Mocanu, Mihai Rusu
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| It was studied the possibility of using as texture agents in the formulation of some epoxy-polyesteric powder dyes of a cellulosic derivative - encoded AT1 and of an acrylic resin - encoded AT2. From the analysis of the influence of the texture agent AT1 |
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Aspecte reologice la prelucrarea materialelor
plastice prin injectare
Faza de umplere
CATALIN FETECAU
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| The paper deals with the flow analysis of plastic material which flows into the mold cavity using simplifying hypotheses imposed to the injection process. On the basis of software especially developed in C++, the length of the penetration of molten plasti |
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Comportarea termica in conditii neizoterme a unor copolieteri aromatici cu spatiator tetrametilenic
CRISTINA DAMIAN, NICOLAE HURDUC, GABRIELA LISA, SILVIA ALAZAROAIE, NATALIA HURDUC
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| The main aim of this paper is to study the thermal stability of some aromatic copolyethers containing a tetramethylenic spacer. The polymers were synthesized using a phase transfer catalysis technique, starting from 1,4-dichlorobutane and various bisphen |
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Compozite pe baza de matrici termoplastice si materiale de ranforsare termosensibile
Madalina Zanoaga, Yevgen Mamunya, Fulga Tanasa, Vladimir Myshak,
Eugene Lebedev, Cristian Grigoras
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| This paper presents the obtaining of some composite materials using wood waste (wood chips) and polymer. As thermoplastic matrix, a copolyamide polymer having a low melting interval (125-135°C) was used. Composites were obtained using a two-stage technolo |
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Consideratii privind acoperirile organice pe baza de vopsele pulbere colorate
Petronela Catalina Mîndrila, Mihai Rusu
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| It is known that the white organic films based on powder coatings have a large use, especially in the appliance industry; however, due to their decorative role, the colour is one of the important characteristiscs of the powder coatings. In order to obtain |
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Consideratii privind ecuatiile constitutive folosite la studiul maruntirii deseurilor din cauciuc fara insertie
DAN Dobrota
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| The paperwork presents the principal constituent equations used on study of mincing rubber waste without insertion. These equations permit a study of mincing process on analytical ground, without being necessary, in some cases, to conduct experimental re |
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Copolimerizarea alternanta a stirenului cu N-fenilmaleimida
in solutie în prezenta initiatorilor peroxidici
ALINA GEORGETA ENACHE, SORINA GAREA, NICOLAE COBIANU
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| This paper describes the kinetic evolution, in solution, of styrene-N-phenylmaleimide alternating copolymerization. The rate of consumption for the echimolecular composition of the two monomers is shown by the empirical equation VP = kp1.170.4; the |
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Cristale lichide termorigide obtinute din 4,4'-bifenol
CONSTANTIN N. CASCAVAL, ALICE MITITELU
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| Liquid crystalline thermosets with biphenyl mesogen in the main chain were prepared by the curing reaction of diglycidyl ether of 4,4ą-biphenol (DGEBP) in presence of methylene-di-chloro-diethylaniline (MCDEA) and 2-amine-biphenyl (2-ABP), used as the cur |
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Influence of Conformational Parameters on Physical Properties of Heterocyclic Polymers Containing Pendent Bulky Groups
Corneliu Hamciuc, Elena Hamciuc
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| Conformational parameters of some heterocyclic polymers containing phenyl-substituted quinoxaline units, phthalimide, 3,4,5,6-tetrachlorophthalimide or phenoxy groups, have been calculated by Monte Carlo method. Several physical properties such as solubil |
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Liganzi macromoleculari preparati prin functionalizarea copolimerilor S-DVB clorometilati cu amine aromatice
CORNELIU-MIRCEA DAVIDESCU, ADRIANA POPA
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Synthesis of orto- and para-aminophenols groups grafted on copolymers is described. The method is applied, extended and optimised for gel-type styrene-divinylbenzene copolymers (S-DVB) with 5 and 7 degree of crosslinking.
Keywords: orto- and para- |
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O noua metoda de sinteza a bismaleimidelor cu structura
alifat-aromatica cu legaturi amidice / esterice
Constantin Gaina, Viorica Gaina
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| A series of bismaleimides with amide or ester linkages were prepared by condensation-dehydrochlorination reaction of 3(4)- a-chlorosuccinimidobenzoic acid chloride with diamine or diols. The monomers were characterized by thermal stability using dynamic t |
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Poli(e-caprolactama) ca suport pentru polimeri bioacizi. I. Caracterizarea structurala prin spectroscopie FT-IR
Elena Rusu, Dana Dorohoi, Gheorghe Rusu, Ion Hurjui
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| The aliphatic polyamides provide an extremely broad range of available properties for biological and medical purposes. They can be used as support in biocidal systems. The biocidal polymer coatings can contain hydantoin, imidazolidinone, isocyanurate or o |
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Studii cu privire la amelioratori de viscozitate pentru uleiuri multi- grad. I. Parametri de solubilitate
IOANA STANCIU, MINODORA LECA
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| The global and partial solubility parameters and radii of interaction spheres of two copolymers recommended as viscosity improvers for multi-grade mineral oils INFINEUM SV 260 and KELTAN 4200 were determined from solubility data and intrinsic viscosit |
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Studiul extractelor de rozmarin si salvie pentru protejarea polietilenei impotriva oxidarii termice
MARIUS BUMBAC, LAURA MONICA GORGHIU, CRINELA DUMITRESCU, SILVIU JIPA, RADU SETNESCU
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| This paper presents the effect of some rosemary and sage extracts on the thermal stabilization of low-density polyethylene (LDPE). IR and UV spectra of these extracts indicates that the major substances are carnosic acid, carnosol and epirosmanol. Chemil |
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Tranzitii vitroase la amestecuri de polimeri pe baza de
polistiren/polisulfona si derivatii lor clorometilati
Nicolae Aelenei, Ecaterina Avram
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| Glass transition temperatures were determined by differential scanning calorimetry (DSC) for the polymer mixtures of polystyrene(PS)/polysulfone(PSF) and their chloromethylated derivatives (CMPS/CMPSF). The polymer mixture was prepared by precipitation me |
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Relatii exacte in analiza fenomenologica a proceselor reodinamice de relaxare/retardare
in vascoelasticitatea liniara a sistemelor polimerice I. 2 Marimi caracteristice secundare in cazul proceselor
de deformare controlata
Horia Paven
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| The secondary rheodynamic quantities in case of strain(e)-controlled relaxation processes, including the storage, loss, and absolute compliances as well as the corresponding loss factor, are considered from the standpoint of frequency dependence. The exa |
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Validarea la impact a modelului cu elemente finite a unui absorbitor
de energie confectionat din polimeri
Iulian Lupea, Joel Cormier
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| The paper presented aspects relats to the thermoforming simulation with T-SIM and the crash simulation with LS-DYNA, of a polymeric energy absorber called SafetyPlasticź. SafetyPlasticź is an energy absorbing technology that offers a performance, cost, a |
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Aplicatii ale polimerilor in combaterea poluarii electromagnetice
Gheorghe Samoilescu
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| This paper presents some background aspects of the applications of polymers in the area of the screening of stationary, quasistationary and nonstationary electric and magnetic fields on the Black Sea coast. Some solutions for the electromagnetic depolluti |
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Comportarea termica a polisilanilor si transformarea
in material ceramic
Gabriela Sacarescu, Mihaela Simionescu, Rodinel Ardeleanu, Liviu Sacarescu
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| This work presents the study of the pyrolysis process of polysilane preceramic precursors. This study stated that the yield in ceramic material is influenced by the heating rate and depends on the chemical structure and polydipersity index of the polysila |
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Compozite poliamida 6/pulbere de bronz obtinute in situ via polimerizarea anionica a epsilonĄVcaprolactamei in prezenta
pulberii de bronz
Gheorghe Rusu
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| In situ via anionic ringĄVopening polymerization of epsilonĄVcaprolactam in the presence of bronze microparticles was promoted as a route for the synthesis of nylon 6/bronze composites by rotational molding. The process was performed at 160 oC well below |
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Consideratii asupra relatiei intre calitatea
produsului si sistemul de macinare in reciclarea materialelor plastice
Dumitru TUCU, Vasile ROTARESCU, Ilare BORDEASU, MIHAI BAYER, Anton HADAR
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| This paper presents some considerations about influences of the milling process on the quality of plastic materials in the process of recycling. There are presented the advantage and disadvantage of the use of the proposed milling system, economic and ser |
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Cristale lichide termotrope.
Tipuri de grupari mezogene
Luminita Marin, Sonia CIOCILTEU
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The paper presents definitions of the main kind of mesogenic groups recognized by IUPAC. For a better understanding of the terms, for every type of mesogen, we attached a structure or picture.
Keywords: liquid crystals, mesogenic group
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Debitul si evolutia presiunii la extruderul cu doi melci corotativi (I)
Valeriu V. JINESCU, Nicoleta Sporea
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| The expresion of the twin-scren extruder flow rate was established in correlation with the filling degree and pressure variation along the screw. The authors used the hypothesis of the single-screw extruder flow analysis and the relation of the single-sc |
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Influenta sarcinilor spatiale asupra comportamentului
materialelor electroizolante polimerice
Doina Elena Gavrila
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| The paper defines the notion of charge space whose study is very important for the improvement of the characteristics of the polymeric electroinsulated materials. The latest nondistructive methods used for the determination of ions improvement are descri |
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Modelarea curgerii rasinilor termorigide
prin mediul poros al unei structuri compozite.
Horatiu Iancau, Marian Borzan, Alina Crai, Mihai Bayer, STEFAN FUNAR
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| Mathematical modeling of resin flow into the cavity of the mold is a very complex problem due to the porous medium realized by reinforced material. The paper is presented the start evolution and the velocity of the flow for the polyester resin thermosetti |
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Modificatori polimerici pentru scaderea
penetratiei bitumului rutier
MIHAI DIMONIE, DOINA DIMONIE, GABRIEL VASILIEVICI , VASILICA BEICA,DORIN BOMBOS
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| The high values of the penetration and of the ring and ball softening point of the distillation road bitumen are determined by the absence from its composition of the high molecular weight fraction, solved in this medium. The effect of the modification of |
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Optimizarea sintezei poliuretanului pentru lagare de izolare pasiva
STEFAN OPREA, STELIAN VLAD
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| Polyurethane elastomers (PEs) based on polyether diols and polyester diols can be used as passive isolation bearings in building applications. In the present study polyetherdiol, polyesterdiol, aromatic diisocyanate have been used in polyurethanes, using |
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Probleme la sudarea tevilor PEHD
Mihaela Popescu, VERONICA ARGESANU, MIHAELA JULA
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| The paper presents the international trends in the use of PEHD pipes considering losses in the distribution pipeline. It also presents elements imposed by the quality assurance conditions, from the PEHD welded pipes execution point of view, of welding tec |
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Rasini acizi rezinici/anilin/p-nonil fenol/formaldehidice.
Sinteza si caracterizarea
FANICA MUSTATA, IOAN BICU
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| Formaldehyde resins containing resin acid derivatives in their structure were synthesized. The insertion of resin acid derivatives into molecular chains was carried out to improve the cohesive strength of pressure sensitive adhesives. IR, 1H-NMR spectrosc |
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Rolul foliilor polimerice fotoselective multistrat in crearea microclimatului optim pentru culturi tehnice. I
Elena Grosu, Eleonora Nemes, Maria Rapa, Constantin Opran, TEODOR PETRESCU
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| Plasticulture is a system of growingcrops in a way so that a significant benefit is derived from using plastic polymers. We have obtained a threeyer polymeric foil with photoselective additives in order to modificate the microclimate. This foil was subjec |
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Sinteza si caracterizarea unor silani
cu grupe functionale -CHO
Viorica Hamciuc, LUCIA PRICOP
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| Some organosilicone monomers with -CHO functional groups were synthesized by a condensation reaction between the methyl- or phenyl-chlorosilanes and an aromatic aldehyde. The products were characterized by IR and 1H-NMR spectroscopy, elemental analyses, |
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Studiu comparativ intre conductele din polietilena si otel privind comportarea acestora in regim tranzitoriu
CORNEL Trifan, SORIN NEACSU, MIHAI ALBULESCU
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| This paper proposes a genuine mathematical pattern for the study of the unsteady phenomena that characterize the working out of polyethilene and steel repartition pipeline from the natural gas distribution networks. The calculation programme elaborated on |
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Studiul posibilitatilor de dirijare
a reactiei de alcooliza in suspensie a poliacetatului de vinil.
Gheorghe Hubca, Camelia Hodosan, Paul Octavian Stanescu, Mihai Dimonie, Ioana Dusescu
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| The present work investigates the possibility to control the alcoholysis reaction in order to obtain various sorts of polyvinyl alcohol with a predetermined degree of alcoholysis and high block copolymer character. On this purpose, two methods are suggest |
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Studiul reactivitatii unor monomeri acrilici si metacrilici
cu două duble legaturi
Geza Bandur, Lucian Rusnac, Avram Petrean, Gerlinde Grandtner, Vasile Pode, Nicoleta Plesu,
Marc J.M. Abadie
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| This paper presents a study of the reactivity for some acrylates and methacrylates with two double bonds: diethylene glycol diacrylate (DEGDA), tetraethylene glycol diacrylate (TTEGDA), dipropylene glycol diacrylate (DPGDA), tripropylene glycol diacrylate |
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Cercetari pentru determinarea absorbtiei de apă la compozite - rasină si fibre textile
GELICA STĂNESCU, MONICA MATEESCU, DUMITRU NEAGOE |
| Due to physical properties of the composite materials based on resin textile fibres cover, in the present different utilisation areas such as: terestrial, aerian and naval transport, civil and industrial engineering, medical tehnique, food industry, spo |
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Decarbonatarea amestecului de materii prime intr-o instalatie de obtinere a clincherului
DOREL RADU, CORINA IBRIS |
CaCO3 is the main component of the raw materials powder mixture to obtain Portland cement.
In the clinkerization process, with increasing the working temperature, physico-chemical processes take place in the raw materials, the most important being the en |
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Model de relaxare pentru materiale polimerice in teoria ereditare a elasticitatii
VIOREL PUIU PAUN |
In this paper a relaxation model for polymeric materials is presented.
Keywords: relaxation, theory of elasticity, creep
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Modelarea si simularea polimerizarii radicalului liber de metil metacrilat cu aditia intermediara a initiatorului si modificarea in trepte a temperaturii
SILVIA CURTEANU |
| In this paper, some models for gel and glass effects a new empirical model and Chius model are checked under batch and semibatch, isothermal and nonisothermal reaction conditions. The chemical initiated free radical polymerization of methyl methacryl |
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Optimizarea debitului extruderelor monomelc
COSMIN V. JINESCU |
| The relationship for the calculus of flow in a single screw extruder was inferred based on the analysis of the real movement of the powder material in the feeding zone, considering the screw rotating and the barrel stationary. The relationship is applicab |
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Poliamide cu grupari cinamoiloxietil in catene laterale
MARIOARA ONCIU, ELENA RUSU |
Some photosensitive structurally different polyamides were obtained using as starting monomers various dicarboxylic acids and 2-(cinnamoyloxy)ethyl-3,5-diaminobenzoate. Their synthesis is based on the Yamazaki-Higashi procedure. The characterization of |
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Protectia cauciucurilor vulcanizate cu cupluri de antidegradanti diaminici si aditivi selectati
GHEORGHE IVAN, AURELIA MEGHEA, MARIA GIURGINCA, NICOLETA IFTIMIE |
Aromatic diamines are antidegradants with outstanding capability in protection against oxidative and ozone destruction of elastomers and elastomer-based compounds. Their performances are dependent, among others, on their solubility in elastomer matrix |
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Studiu asupra unor polimeri sintetici biodegradabili.
Reactii si mecanisme de initiere a proceselor de biodegradare
NITA TUDORACHI |
| By exposure to the environment of polymer wastes, the disintegration and degradation processes take place by simultaneous and concurrent mechanisms, as photodegradation, hydrolisys, thermooxidation and biodegradation. The latter may be described as a com |
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Studiu cinetic asupra copolimerizarii cationice a octametilciclosiloxanilor cu oligomeri metilhidrogensiloxanici
VIORICA HAMCIUC, LUCIA PRICOP |
| The copolymerization of octamethylcyclotetrasiloxane and methylhydrogensiloxane oligomers was carried out using a styrene-divinylbenzene copolymer with sulphonic groups as catalyst (VIONIT CS-34C). The conversion versus time function was studied at differ |
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Studiul efectului unor coloranti reactivi asupra stabilitatii
la termooxidarea polipropilenei izotactice
CRINELA DUMITRESCU, SILVIU JIPA, LAURA MONICA GORGHIU |
| This work presents a study on the interaction that a phenolic hindered antioxidant (Irganox-1076) and new reactive dyes derivated from 3H-aza-1-oxa-2H-thioxo-5,8-phenalendisulphonic acids, have upon izopolipropylene thermooxidation. The study was performe |
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Materiale avansate pe baza de rasini epoxidice. 3. Polimeri pe baza de cristale lichide cu difenil mezogen
Constantin N. Cascaval, Alice Mititelu
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| Epoxy resins with mezogenic groups were prepared from diglycidyl ether of 4,4'-bisphenol (DGEBP), as rigid block, and 4,4-diaminodiphenyl sulphone (DDS), as curing agent. A nematic-like structure was developed in time, in the temperature range of the cur |
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Acoperiri organice pe baza de vopsele pulbere
VII. Influenta modificatorilor de curgere asupra caracteristicilor
vopselelor pulbere epoxi-poliesterice
Mihai Rusu, Carmen Elena Mocanu
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| It was studied the influence of urheomelamineformaldehydic resin adds, as flow modifier, on the main characteristics of some epoxi-polyesteric powder dye of white signal type and of cover films made with these. It was established that the introducing in |
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Amestecuri copolimeri EVA - ceruri
Livia Popa
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| Waxes are critical to hot melt adhesives performance in terms of thermal stability and mechanical properties. The thermal behavior of EVA with microcrystalline and polyethylene waxes have been investigated by infrared spectroscopy and physical-mechanical |
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Aspecte privind reactia alcoolului polivinilic
cu acidul fosforos
OANA PETREU, T. VLAD-BUBULAC, GEORGETA CAZACU
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| Powders of poly (vinyl alcohol) with different degrees of polymerisation and hydrolysis have been reacted with phosphorous acid in homogeneous conditions. The influence of experimental conditions on the substitution degree has been investigated. Analytica |
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Bismaleimide functionale
continand derivati ai acidului salicilic
CAMELIA Hulubei
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| Two new bismaleimides with preforming ester and amide linkages in the main chain were prepared by the reaction between the chloride of 4-maleimidobenzoic acid and 4 (5) amino- salicylic acid. The structures were characterized by elemental analysis, infr |
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Bloccopolimeri stiren-butadienici utilizati în recircularea polietilenei de inalta densitate recuperata
Paul Ghioca, Emil Buzdugan, Corneliu Cincu, Bogdan Spurcaciu, Lorena Iancu,Catalin Zaharia
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| This paper presents the influence of styrene-butadiene block-copolymers on the modification of high density polyethylene wastes. The modification of this polyolefine is a means of improving the mechanical properties, especially the impact strength, in or |
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Cinetica oxidarii catalitice a fenolilor cu oxigen molecular in prezenta unor compusi coordinativi ai manganului cu baze Schiff
AUREL PUI, DANUT GABRIEL COZMA, MIHAELA PUI
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| The 2,6-di-tert-butylphenol (DtBP) can be oxidated with O2, in the presence of some catalysts based on M(II) complexes with Schiff bases, in DMF. The metal complexes contain Mn and tetradentate Schiff bases derived from salen, as ligands. The transformat |
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Efectul iradierii asupra LPDE in mediu de risc
Traian Zaharescu, Maria Giurginca, Cornel Podina
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| Low density polyethylene films were g-irradiated in various oxidative environments: air and aqueous solutions containing hydrochloric acid and different chlorides (MnCl2, CuCl2, NiCl2, and CoCl2) in the concentration of 10 % (w/w). Radiochemical degradati |
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Limite în activarea ultrasonică a materialelor polimerice
in procesele de injectare si extrudare
Tudor Iclanzan, Daniel STAN
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| The paper presents some basic considerations to establish the optimum conditions for designing the ultrasonic equipment employed in plastic flow activation. In the first part, the paper presented general considerations and recommendations for the design o |
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Optimizarea configurativa a unor placi realizate din compozite stratificate si armate cu fibre
Anton HADAR, Gabriel JIGA, Mihai BAYER
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| This paper presents two different procedures for the configuration optimization of a glass fibre reinforced laminate in order to enlarge the load capacity of different structures where these materials could be embedded. By some experimental tests, the au |
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Plastifianti si lubrifianti polifunctionali de tip sebacati
Liviu E. Mirci, Sorina Boran
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| The paper deals with the synthesis and characterisation as plasticizers and/or lubricants of some unsymmetrical diesters of sebacic acid by using superior branched aliphatic alcohols, such as 2-ethyl-hexanol, isodecanol and isotridecanol, along with compl |
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Sinteza si studiul proprietatilor termice ale unor noi
polihidrazide si poli-1,3,4-oxadiazoli cu grupe
acetiloxi-benzamidice in catena laterala
Mariana-Dana Damaceanu, Ion Sava, Maria Bruma
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| A series of five new aromatic polyhydrazides containing pendent acetyloxybenzamide groups has been synthesized by low-temperature solution polycondensation of 5-(4-acetyloxybenzamido)-isophthaloyl chloride with dihydrazides of terephthalic, isophthalic, |
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Sinteza unor noi aldehide aromatice utile pentru prepararea de mezogeni azometina
Luminita Marin, Vasile Cozan
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| New aromatic aldehydes were prepared in the conventional literature manner by Williamson etherification reaction of p-chlorobenzaldehyde with p-substituted phenols, or by esterification reaction of cyanoacetic acid with p-hydroxybenzaldehyde in the presen |
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SMARANDA ILIESCU, GHEORGHE ILIA, ADRIANA POPA, GHEORGHE DEHELEAN, NICOLETA PLESU,
LAVINIA MACARIE
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| The paper investigates the effect of organic phase on yield and inherent viscosity in liquid-vapor interfacial polycondensation and the effect of reaction temperature and reagents molar-ratio on yield, inherent viscosity and molecular weight in liquid-liq |
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Studii privind eliberarea codeinei din matrici
polimere metacrilice
Loredana Elena Nita, Aurica P. Chiriac
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| The delivery pharmacokinetics of the codeine, which was entrapped in some polymeric matrices, was studied. As matrices, the methyl methacrylate homopolymer and methyl methacrylate copolymers with different percentage of 2, 3 epoxypropyl methacrylate were |
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Studiul influentei produsilor secundari rezultati în sinteza
4,4-bismaleimidodifenilmetanului asupra comportarii termice
ale acesteia cat si a răasinilor poliaminobismaleinimidice rezultate
Constantin Gaina, Viorica Gaina
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| The main route of obtaining bismaleimides is the reaction between maleic anhydride and primary diamines. First stade occured with forming maleamic acid, then cyclicised to bismaleimide in presence of the acetic anhydride, sodium acetate or other dehydrat |
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Calcularea grosimii straturilor de substanta
anizotropa utilizate in analiza starii de polarizare a radiatiilor luminoase
LEONA DUMITRASCU, IRINA DUMITRASCU, DANA-ORTANSA DOROHOI
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Theoretical and experimental bases for estimating the thickness of the thin anisotropic layers in order to obtain and analyze the total polarized light are discussed, having in view the numerous applications in fundamental and applicative researches. Th |
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Caracteristicile suprafețelor unor filme subțiri de poli(azoarilene)
Anton Airinei, Daniel Timpu, Virgil Barboiu, Elena Rusu
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| Transparent thin films of poly(4,4-azodiphenyl) and poly(4,4-azostilbene) were obtained by vacuum thermolysis or photochemical decomposition of the corresponding aromatic diazides. Taking into account the working conditions, the thickness of transparent |
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Comportarea termica a nanocompozitelor biodegradabile
pe baza de alcool polivinilic si amidon
Doina Dimonie Constantin Radovici, Catalin Zaharia, Gabriel Vasilievici, Aurel Stoleriu
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| The biodegradable polymeric materials can be achieved based on several methods among which, the compounding of natural polymers with synthetic ones has a significant utility. The biodegradable materials based on polyvinyalcohol (PVOH) and starch have a |
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Comportarea termica a unor polistireni cu grupe
viologen in catena laterala
ECATERINA AVRAM, GABRIELA LISA, NATALIA HURDUC
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| Polystyrenes with pendent diquaternary 4,4-bipyridinium groups are polystyrenes containing pendent viologen groups. They were obtained by the reaction of chloromethylated polystyrene with N-monoquaternary-4,4- bipyridinium bromides as: N-(p- H, NO2, Cl) |
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Consideratii asupra factorilor care influenteaza durabilitatea cilindrilor valturilor la maruntirea deseurilor din cauciuc
Dan Dobrota
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| The paper presents the changes in chemical composition and hardness of cylindres used for grinding of rubber wastes. Based on experimental results obtained, some technical solutions can be suggested in order to determine a considerabile growth the life eq |
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Copolimeri maleimidici alternanti functionalizati
CAMELIA HULUBEI
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| Two copolymers based on N-(4-formyl-fenoxy-4'-carboylphenil)maleimide have been synthesized. The first one was prepared by free radical polymerization of this monomer with styrene. The second one was obtained by chemical modification reaction with p-am |
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Distributia timpului de retinere
in extruderul cu doi melci corotativi
Nicoleta Sporea
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| The residence time distribution at the exit of mixing zone in a fully intermeshing, corotating twin screw extruder was determined with a stimulus-response technique. The operating parameters investigated were screw speed and feed rate. The residence time |
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Durabilitatea tevilor de polietilena pentru conductele
prin care se vehiculeaza gaze naturale contaminate
cu hidrocarburi lichide
Alexandru Pupazescu, Gheorghe Zecheru
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| The paper analyzed the chemical resistance of polyethylene (PE) pipes, some attention paid to the general phenomenon of degradation which influences polyethylene life. The influence of synthetic condensate (50% (by mass) n-decane and 50% (by mass) 1-3-5 |
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Efectul iradierii g asupra acoperirilor poliuretanice
Rodica Pirvu, Corneliu Podina, Traian Zaharescu
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| In this paper, the behaviour of polyurethane protective sheets on metallic surfaces in g-radiation field was studied. The irradiation effects consist of the decrease in the sheet thickness and the worsening in the brightness of modified polyurethane prote |
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Fabricarea structurilor celulare solide cu celula inchisa
din ABS P400 prin procedeul de fabricare rapida
pe straturi Fused Deposition Modeling
DIANA POPESCU, ANTON HADAR, COSTEL EMIL COTET
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| The use of Rapid Prototyping (RP) processes in manufacturing cellular solids offers the advantages of controlling the distribution, dimensions and interconnection of cells, which influence their micro and macro-structural properties. But not all RP proces |
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Filme de polimeri pe baza de poli-1,3,4-oxadiazoleteri
Corneliu Hamciuc, Elena Hamciuc
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| Thin films, in the range of tens of micrometers thickness, have been prepared by casting onto glass plates the chloroform or N-methylpyrrolidone solutions of poly(1,3,4-oxadiazole-ether)s. The polymers have been prepared by nucleophyilic substitution poly |
|
Finisarea in trepte a granulatiei
aliajelor de aluminiu deformabile
Mihai Butu, Petru Moldovan
|
| In this paper the experimental results obtained at grain refining of 6082 aluminum alloy are presented, using an original method which consists in insertion of refining master alloys in two stages: in the first stage the AlTi5 elaborated at low temper |
|
Impedanta termica modelata neliniar
pentru polimerii folositi in industria electronica
VALENTIN MARANESCU, NICOLETA PLESU, CORNELIU TOMA, CATALIN CALEANU, MIHAIL TANASE
|
| The microelectronic package continues to evolve in order to improve the performance and integrate new technology such as multidie architectures, thinner substrates, increasing integration of passive components, increasing thermal design power and lead |
|
Influenta parametrilor de prelucrare asupra caracteristicilor structurale ale compozitelor polimerice pe baza de EPDM reticulat
in matrice poliolefinica
SANDA VISAN, VIRGINIA CIOBOTARU, FLORICA IONESCU, CONSTANTIN GHIGA
|
| The structural characteristics of polymeric composites based on EPDM, (ethylene-propylene-dien monomer) rubber, which have various percentages of high density polyethylene, were studied by IR spectroscopy and optical microscopy, evidencing the influence o |
|
Monomeri ai bismaleimidelor si biscitraconimidelor cu grupari SO2.
MITICA SAVA
|
| Various bismaleimides and biscitraconimides containing ester and ether units in the main chain and having SO2 groups were synthesized. Monomers with ester units were synthesized by condensation between 3(4)-maleimidobenzoyl chloride or 4-citraconimid |
|
Polifosfati obtinuti prin tehnica gaz-lichid
SMARANDA ILIESCU, GHEORGHE ILIA, ADRIANA POPA, LAVINIA MACARIE
|
| A solvent and catalyst-free synthesis of a polyphosphate was accomplished. The reaction involved a gas-liquid polycondensation between phenylphosphoric dichloride and phenolphthalein. The polyphosphate was characterized by IR, 1H-NMR, inherent viscosity, |
|
Polimeri cristale lichide termotrope
Controlul stabilitatii termice
Luminita Marin
|
| This paper focuses on the relationships between the chemical structure of mesogenic polymer molecules and the temperature range over which they can form liquid crystalline phases. The purpose of this presentation is to illustrate the influence of the vari |
|
Studiu numeric privind comportarea unor
materiale termoplastice la calandrare
Catalin FETECAU, Felicia STAN
|
| For calendaring sheets with a desired final thickness, the design process of the calender unit includes, among other parameters, the calculation of the flow velocity and pressure fields in the gap between the rolls. In this paper, the fundamental aspects |
|
Studiu privind obtinerea de noi elastomeri termoplastici ionici prin modificari chimice ale produselor existente
Maria Daniela Zuga, Corneliu Cincu
|
| In this study, the ethylene propylene terpolymer elastomer (EPDM) was chemically changed by sulphonation which was subsequently used in preparing compounds by adding neutralization agents, ionic and non-ionic plasticizers, fillers, and polyolefines with t |
|
Studiul unor polioxadiazol-amide continand siliciu
Mariana-Dana Damaceanu, Maria Bruma
|
| Three aromatic silicon-containing poly(1,3,4-oxadiazole-amide) were synthesized by solution polycondensation reaction of aromatic diamines containing performed 1,3,4-oxadiazole ring with a diacid chloride incorporating diphenylsilane unit. All polymers ar |
|
Uleiuri de baza pentru lubrifianti obtinute din amestecuri de uleiuri vegetale si di-2-etil-hexil-adipat
COSMINA PUSCAS, DORINA MODRA, GEZA BANDUR, REMUS NUTIU
|
| Lubricants based on vegetable oils are a growing in attraction various applications. Environmentally friendly, vegetable oils and their derivatives constitute alternatives for a large variety of mineral based lubricants. New lubricating oils obtained fr |
|
Copolimerizarea anionica a ecaprolactamei cu laurolactama prin procedeul de formare rotationala
GHEORGHE RUSU |
| This paper deals with synthesis and characterization of some copolyamides 6/12 obtained by rotational molding via activated anionic ringopening copolymerization of ecaprolactam with laurolactam. Sodium bis<(2metoxyetoxy)ecaprolactam> aluminate, as ini |
|
Electrod cu matrice PVC, selectiv la surfactantul anionic laurilsulfat de sodiu
CRISTINA MIHALI, GABRIELA OPREA, ELENA HOPIRTEAN |
| A laurylsulfate-selective electrode is presented. The sensing material of the electrode consists of an ion pair 1:1 water insoluble salt that has been prepared using sodium laurylsulfate and hexadecyl trimethylammonium bromide and was immobilized in a PVC |
|
Flavonoide
II. Metode de investigare
CONSTANTIN ANDREI, CARMEN MOISE |
| Flavonoids pigments exert a broad range of biological activities in both plants and animals. Natural polyphenols mainly occur as glycosilated molecules, usualy with a b-linked sugar. In this paper are cited several methods and techiques uses in flavonoi |
|
Metoda pentru calculul variatiei temperaturii pe adancimea
canalului melcului la extrudarea materialelor polimerice
VALERIU V. JINESCU, NICOLETA TEODORESCU, COSMIN V. JINESCU, ANGELA CHELU |
| In a previous paper <1> there were obtained the relations permitting the calculus of the temperature variation on the depth of an extruder screws channel. In this paper it is shown how to calculate some of the parameters comprised in the previous stated |
|
Model de alungire pentru materiale polimere
VIOREL-PUIU PAUN |
| In this paper it is presented a creep model in the theory of viscoelasticity for polymeric materials. |
|
Noi copolimeri de coordinatie hibrizi ai Mn(II)
IOAN ROSCA, LIVIA OPREA, DOINA SIBIESCU, DANIEL SUTIMAN, ADRIAN CAILEAN, MIHAELA VIZITIU |
| This paper presents the synthesis and study of some Mn(II) coordination polymers hybrid with the following acids as ligands: dibuthilphosphinic, dibuthiltiophosphinic, dibutildithiophosphinic, dioctilphosphinic, dioctiltiophosphinic, dioctilditiophosphin |
|
Participatii masice si volumice la compozite rasina-fibre textile
GELICA STANESCU, MONICA MATEESCU
|
| Manufactured in various geometric forms, containing secondary materials (colorants, reinforcements, fireproof etc.), all these make the composites based on resin-textile fibre, basic materials for obtaining lateral walls, ceilings, floors, compartments f |
|
Profilul optimal al temperaturii in polimerizarea radicalica
a metacrilatului de metil
CORNELIU PETRILA, SILVIA CURTEANU, STEFAN UNGUREANU |
The main purposes of this article are: 1) the minimization of an objective multi-criterial function which implies the reaction time, the polidispersion coefficient and the monomer conversion;
2) the obtaining of reaction conditions (temperature and init |
|
Radiostabilitatea polietilenei de joasa densitate in stare aditivata
TRAIAN ZAHARESCU, SILVIU JIPA, BARBARA GIGANTE, MARIA ALEXANDRA ESTEVES, RADU SETNESCU, TANTA SETNESCU, MADALINA DUMITRU, LAURA MONICA GORGHIU |
| The radiation stability of low density polyethylene in the presence of several additives as antioxidants (two derivatives from rosin, two commercial stabilizers, Irganox 1076 and Irganox 1081 and elementary selenium) was carried out by oxygen uptake metho |
|
Reticularea unor elastomeri dienici folosind un nou accelerator imidazolinic. Influenta unor antioxidanti
GHEORGHE IVAN, ELENA BUGARU |
| This paper presents the performance of two aminic antioxidants (TMQ and PBN) and a phenolic antioxidant (SPH) in formulations based on diene rubbers, typical for tyre treads. An imidazoline was used as secondary accelerator and the influence of antioxida |
|
Sinteza si caracterizarea unor rasini
p-aminofenol / o-crezol / formaldehidice
FANICA MUSTATA, IOAN BICU |
| The ortocresol, the p-aminophenol and the formaldehyde were taken in different molar ratios and condensed in the presence of hydrocloric acid as catalyst and of toluene) N-methyl pyrolidone mixture as extraction agent of the reaction water. The condensin |
|
Sisteme de stabilizare UV pentru stratul de suprafata (gel coat) din poliesteri nesaturati
CEZAR CAPANESCU, CORNELIU CINCU |
| There were investigated the performances of some UV stabilizers systems in the surface layer (gel coat) of unsaturated polyesthers. The changes in colour and in gloss were determined using accelerated degradation methods as well as natural ageing. The cor |
|
Stabilitatea unor acoperiri semiconductive bazate pe polianilina
NICOLETA PLESU, GEZA BANDUR, IONEL MANOVICIU, SIMONA POPA, DORIN JURCAU |
| The replacement of classical materials used in industry with other more important, cheaper and environment friendly ones and also the prevention of corrosion is one of the goals in the research area. Electrotechnical industry and engineering needs this sp |
|
Acoperiri organice pe baza de vopsele pulbere
VI. Alegerea polimerilor pentru vopsele pulbere epoxi-poliesterice
Mihai Rusu, Carmen Elena Mocanu
|
| In this paper it is analyzed the influence of epoxy and polyesteric resins reactivity on the characteristics of two types of epoxy-polyesteric powder dyes (7024 graphite grey and 9005 signal black, according to the RAL Design Classic K 7 Card, RAL-Farben, |
|
Cristale lichide polimere
Terminologie si concepte
Luminita Marin, Vasile Cozan
|
| The paper presents, in a general and sugestive manner, some basic knowledge about nomenclature and concepts usually encontered in the field of liquid crystalline materials (both low molecular compounds and polymers). There are briefly presented: definiti |
|
Diarilamine si fenilendiamine termostabilizatori
pentru polietilena
SILVIU Jipa, TRAIAN Zaharescu, RADU Setnescu, Tanta Setnescu, Madalina Dumitru,
Laura Monica Gorghiu, Crinela Dumitrescu
|
| Thermal stability of low density polyethylene stabilized with different diamine compounds: N-phenyl-1-naphtyl-amine, N-cyclohexyl-N-phenyl-p-phenylen-diamine, N-(1,3-dimethyl-butyl)-N-phenyl-p-phenylen-diamine and N, N-di-(1,4-dimethylpentyl)-p-phenyle |
|
Evaluarea proprietatilor mecanice ale filmelor poliuretanice precipitate in mediu de agenti reactivi
STEFAN OPREA
|
| Segmented poly (ester-urethanes) elastomers based on poly (ethylene diethylene adipate) diols as a soft segment and aromatic diisocyanates in the hard segment were synthesized by a conventional method. The precipitated polyurethane films have been degrade |
|
Influenta continutului de segmente dure asupra comportarii mecanice a unor poli(eter-uretan-uree)
STELIAN VLAD
|
| In this study, a series of three different thermoplastic poly(ether-urethane-urea)s were synthesized from hexamethylene diisocyanate (HDI), polypropylene glycol (PPG) as macrodiols and hexamethylene diamine (HMDA) as chain extender. The molecular weights |
|
Materiale avansate pe baza de rasini epoxidice. Retele interpenetrante de polimeri
Constantin N. Cascaval, Dan Rosu, Liliana Rosu
|
| Interpenetrating polymer networks (IPNs) are a special type of polymer blends, constituted by combination of two or more network polymers, synthesized in juxtaposition. The synthesized IPNs were carried out in order to improve the material properties of m |
|
Noi ajutatori de procesare a polimerilor in clasa ftalica
Liviu E. Mirci,
Sorina Boran
|
| The paper presents results concerning the synthesis and characterization, as polymer processing aids, plasticizers and/or lubricants, of some diesters of unsymmetrical structure of phtalic anhydride, by taking into account aliphatic alcohols such as C3, C |
|
Polimeri degradabili
Siloxani în structuri polimerice degradabile hidrolitic
Maria Cazacu, Carmen Racle, Anton Airinei, Angelica Vlad, Mihai Marcu
|
Based on the evaluation of the position occupied by silicones in biomaterials field in general, and in hydrolytically degradable materials in particular, some original results obtained in this direction are presented.
Keywords: biomaterials, silicone, s |
|
Prepararea si caracterizarea termica a unor amestecuri de rasina epoxidica si poliaminobismaleinimide
MITICA SAVA
|
In this study there were investigated some mixtures obtained from epoxy resins and polyaminobismaleimides. The preparation, working conditions and their characterization by IR, softening points and thermogravimetric analysis are also given.
Keywords |
|
Reactii Wittig-Horner pe suporturi de tip stiren-divinilbenzen in conditiile catalizei prin transfer interfazic
1. Utilizarea aldehidelor grefate
Adriana Popa, Gheorghe Ilia, Smaranda Iliescu, Aurelia Pascariu
|
| The Wittig-Horner reaction is the most general method for regiospecific introduction of carbon-carbon double bounds in organic synthesis. Phase transfer catalyzed reactions are often more easily and cheaply carried out than conventional methods. The paper |
|
Simularea comportamentului mecanic al structurilor ingineresti pe modele realizate din materiale plastice cu proprietati speciale
Nicolae ILIESCU, Costică ATANASIU, Anton HADAR
|
| The paper presents two plastic materials from epoxidic resins and compounded polymers families which have properties to visualize stress field produced by mechanical loadings. Using these properties two experimental techniques, photoelasticity and cromop |
|
Sinteza si caracterizarea unor rasini
p-aminofenol / acizi rezinici anilin / formaldehidice
FANICA MUSTATA, IOAN BICU
|
| The resinic acids, the aniline, the p-aminophenol and the formic aldehyde were reacted at different molar ratios in the presence of hydrogen chlorine. There were obtained formic-aldehyde resins with aminic gropups in their chain. These low molecular mass |
|
Studiul reactiilor 2,4-dihidroxibenzofenonei cu mono- si di-izocianatii
CONSTANTIN BOLCU, FLORIN BORCAN
|
| This paper presents the main aspects of an experimental study concerning the reactions of a bifunctional photostabilizator of benzophenonic type (2,4-dihydroxy-benzophenone) with monoisocyanate (phenylisocyanate) and two diisocyanates (2,4-toluylen diisoc |
|
Comportamentul electric al elastomerilor sintetici la iradierea cu raze gamma
TRAIAN ZAHARESCU, FLORIN Ciuprina
|
| The exposure of ethylene-propylene elastomers to the action of gamma-radiation causes the modification of chemical state of polymer matrix by the formation of oxygenated products. The accumulation of these dipoles modifies the electrical behaviour of mat |
|
Poliaminobismaleimide cu ansamblu amidic. Sinteza si proprietati
MITICA SAVA
|
| A serials of polyaminobismaleimides with different structures, having amide groups, were synthesized by Michael addition of various diamines (4,4-diaminodiphenylether , 1,4-bis(4-aminophenoxy)benzene, 1,2-bis <2- (4-aminophenoxy)ethoxy ethane to bismaleim |
|
Calcularea fluxului de polimeri prin nanopori
ADRIAN-LIVIU PAUN, CRISTIAN TOMA, STEFAN PUSCA
|
The transport process of charged polymer, through a nanopore in a biological membrane is studied. An expression for the polymers flow in terms of the free energy and the friction coefficient is obtained.
Keywords: polymer translocation, polymer flow, n |
|
Cercetari experimentale privind procesarea deseurilor
din cauciuc armat cu insertie metalica
Dan DOBROTA
|
| The paper presents the experimental results obtained in processing rubber waste armed with metallic insertions. The experimental results were obtained appliyng a new technology for processing rubber waste reinforced with metallic insertions. The technolog |
|
Elastomeri poliuretanici pe baza de diizocianati aromatici
pentru sisteme de izolare pasiva.
Stelian Vlad, Stefan Oprea, Adrian Constantin Diaconu
|
| Polyurethanes (PUs) based on polyester polyol and aromatic diisocyanate are used as passive isolation bearings in buildings applications. In the present study polyesterdiol and 4,4-diphenylmethane diisocyanate (MDI) have been used in polyurethanes, using |
|
Estimarea timpului de translocare a polimerilor prin membrana
VIOREL-PUIU PAUN
|
| In this paper the transport process of charged polymer, through a narrow pore in a biological membrane is studied. The translocation time of a single-stranded polymer through a nanopore may be well computed using a physical-chemical model. The general tra |
|
HLB în aprecierea directiilor de aplicare a
copolimerilor grefati polisiloxan-polietilenoxid
Lucia Pricop, Viorica Hamciuc
|
| A series of polydimethylsiloxane-polyethyleneoxide graft copolymers, obtained by hydrosilylation reactions of unsaturated polyethyleneoxides with polysiloxane copolymers containing Si-H groups have been analyzed and characterized from their tensioactive p |
|
Reactii Wittig ale sarurilor cuaternare de fosfoniu cu liganzi macromoleculari functionalizati cu grupari aldehidice
Adriana Popa, Gheorghe Ilia, Corneliu-Mircea Davidescu, Smaranda Iliescu,
Lavinia Macarie, Bianca Maranescu
|
| The Wittig reaction is amongst the most popular methods for regiospecific introduction of carbon-carbon double bonds in organic synthesis. The paper deals with the synthesis of copolymers functionalized with olefin groups by Wittig type polymer-analogous |
|
Sinteza si studiul unor poliimide aromatice pe baza
de 3,3-dimetil-4,4-diaminodifenilmetan
Ion SAVA
|
| New aromatic polyimides have been synthesized by polycondensation reaction of 3,3-dimethyl-4,4-diaminodiphenylmethane with benzophenontetracarboxylic dianhydride or hexafluoroisopropylidene diphthalic anhydride in N-methylpyrrolidinone as a solvent, fol |
|
Studiu numeric comparativ privind comportarea
unor materiale plastice biocompatibile la injectare
Catalin FETECAU, Felicia STAN, Catalin POPA
|
| This paper presents a comparative numerical simulation of an injection moulding process in the case of an acetabular cup, a basic component in a hip prosthesis, made of UHMWPE (GUR 5113, GUR EP 4224, Novatec PP BC4Y 46420) in order to determine the optim |
|
Studiu privind influenta tipului de catalizator metalocenic asupra
gradului de cristalinitate al polietilenei
Sorin Fianu, Constantin Stanescu, Livia Maria Constantinescu, Cosmin Corobea
|
| This paper presents the investigation of the catalytic agent influence on the crystallinity degree of polymers (metallocene polyethylene). Differential scanning calorimetry was the method used to determine the crystallinity. It was underlined that the ca |
|
Studiul transferului de caldura local la topirea unei granule
sferice singulare
STELIAN PETRESCU, ADINA FRUNZA
|
| An experimental study of local heat transfer at the melting of single spherical particles into a flowing liquid is presented in this paper. Local heat transfer coefficient at the particle surface, and local Nusselt number were d |
|
Studiul comportarii reologice a polimerilor
acrilici in peliculizarea materialelor textile
Silvia Mihuta, Michaela Dina Stanescu, Romulus Minea, Andra Tamas
|
| The textile coating is an important process giving rise to new materials. The study of polymer emulsion rheological behavior is very important for establishing the optimal conditions for obtaining the best coated products. The mathematical study of the rh |
|
Studiul comportarii termooxidative a unor materiale fotocromice
RADU SETNESCU, IONICA IONITA, TANTA SETNESCU, CRISTIANA RADULESCU, ANA-MARIA HOSSU
|
| In this paper the behavior at elevated temperatures (thermal oxidation) of some new copolymers exhibiting photochromic properties has been studied. These copolymers were prepared by chemical grafting of some azoic dyes on the support-polymers chains. The |
|
Studiul termoanalitic privind efectul unor insecticide organofosforice asupra rasinii diglicidileter-bisfenol A
Oana Petreu, Tachita Vlad-Bubulac, Corneliu Hamciuc
|
| The effect of an organophosphoric insecticide on the thermooxidative degradation of the diglycidil ether-bisphenol A epoxy resin was investigated, using infrared spectroscopy, thermogravimetric and thermodifferential analysis, pyrolysis-gas chromatography |
|
Validarea experimentala a unui model teoretic folosit in calculul
de rezistenta al structurilor realizate din materiale compozite
ANTON HADAR, ILARE BORDEASU, ION MITELEA, DANIEL VLASCEANU
|
| In the paper, a stress strain analysis in the area of central ligament of a cruciform glass-epoxy specimen is presented. Investigation was done experimentally, using strain gauges technique, by application of six gauges in the stress concentration area. T |
|
Valorificarea polipropilenei atactice in membrane
si bitumuri pentru hidroizolatie
Doina Dimonie, Felicia ANDREI, ANCA TARANU, Simona ILIESCU, Gabriel Vasilievici
|
| The atactic polypropylene (APP) recovery as hydro insulation membranes and / or bitumen presents two main advantages: the great quantities that can be reprocessed and the elevated usage life of the obtained products, a consequence of lack of the photo and |
|
Agenti de retentie de tip polietileniminic si poliaminamid epiclorhidrinic
Sinteza, caracterizare, proprietati
IOAN BICU, FANICA MUSTATA
|
| Two macromolecular products, of polyethyleneimine and of polyamineamide type, were synthesized by the polycondensation of triethylenetetramine with 1,2 dichloroethane with adipic acid and e-caprolactam, respectively. The secondary amine groups of the two |
|
Analiza comportamentului viscoelastic al polimerilor tehnici
prin generarea pulsurilor bidimensionale
STEFAN PUSCA, MARIA-ALEXANDRA PAUN,
CRISTIAN TOMA
|
University of Bucharest, Faculty of Engineering in Foreign Languages, 313 Splaiul Independentei, 060042,
Bucharest, Romania
This paper studies the bidimensional pulses generation in organic materials and technical polymers starting from a practical |
|
Aspecte reologice in procesul de obtinere a hibridurilor neconventionale
GHEORGHE LUNGU, CATALIN DUMITRA, DAN MIRCEA , MARIA LUNGU
|
| The present paper deal with a less known subject from the unconventional technologies namely the fluid flow through a working zone situated between the tool and workpiece electrodes. One take into account the possible types of flow, one establish the mat |
|
Contributii teoretice si experimentale privind influenta parametrilor acustici in procesul de sudare cu ultrasunete
a materialelor compozite inteligente
Gheorghe AMZA, Anton HADAR, Zoia APOSTOLESCU, Gabriel GIRLEANU, LIVIU ANTON
|
| This paper presents the possibilities of creating weldings for various products made of inteligent composite materials. The acoustical parameters and their influence on the quality of the weldings are analysed from the large domain of technological, mecha |
|
Debitul si evolutia presiunii la extruderul cu doi melci corotativi (II)
Valeriu V. JINESCU, Nicoleta Sporea
|
| The expresion of the twin screw extruder flow rate was established in correlation with the filling degree and pressure variation along the screw. Starting from the twin screw extruder flow rate expression, the pressure evolution and the maximum pressure i |
|
Determinarea experimentala a caracteristicii de rigiditate si a modulului de elasticitate a cauciucului utilizand reprezentarea timp-frecventa
Gilbert-Rainer Gillich, GhEorghe Samoilescu, Florin Berinde1, Cristian Paul Chioncel
|
| Rubber is often used as a vibration insulator for technical systems. Its behavior is linear until a deformation of at least 15%, by over this limit the behavior becomes non-linear. This means that the dynamic rigidity and implicitly the elasticity module |
|
Efectele deteriorarii structurii lubrifianților plastici asupra vibrațiilor rulmenților.
GELU IANUS, STEFAN GRIGORAS, CONSTANTIN LUCIAN HANGANU, MARIAN BORZAN
|
| Grease degradation has an important influence concerning vibration level of ball bearings in running time. Resulted sediments after chemical and thermic degradation process alter frequency spectrum, similar with waves on inner and outer races. Unlike wit |
|
Efectele transportului hidrocarburilor prin conducte din material plastic si sticla
GHEORGHE SAMOILESCU
|
| This work presents the results regarding the formation of charge clouds due to the oil movement through non-conductive plastic and glass pipes . We have analzsed the equations that depict the charge distribution, the measurement of electrical charges an |
|
Efectul templantilor asupra obtinerii unor hibride bioxid de titan-ftalocianina
Dan Donescu, Constantin Radovici, Cristiana Bercu, Marius Ghiurea, Cristian Boscornea
|
| The paper is a study regarding the obtaining of TiO2 nanostructured by the sol-gel reaction of tetraisopropoxytitanate in the presence of two templants, CTAB and DA. We are also interested in the effect of PTC on the capacity of nanostructuring. In the |
|
Fabricarea materialelor compozite prin valorificarea superioara
a unui deșeu
GABRIELA STANCIU, CLAUDIA-IRINA KONCSAG
|
| The authors present a way of manufacturing composite materials for building use by adding value to a waste resulted in an oil refinery. The said waste is the spent caustic proceeding from the Fluid Catalytic C racking units. The manufacturing process impl |
|
Influenta proprietatilor componentelor asupra modulelor de elasticitate ale compozitelor polimerice armate cu tesaturi
Liliana Bejan, Adriana Sirbu, Nicolae Taranu
|
| The paper presents the optimisation using genetic algorithms of some characteristics of the composite reinforced with plain weave fabric regarding the type of the polimers used as matrix and the type of the fibres, approaching a new geometric model of the |
|
Insertia chimica a metalelor tranzitionale in interiorul unor structuri polimerice pe baza de silicon
ANGELICA Vlad, MARIA Cazacu, MIHAI Marcu, CARMEN Racles
|
| Some new iron (II)-polymer complex structures having siloxane units included either in ligand structure or as co-monomer partner with an already metal (Fe2+) complexed structure were prepared and characterized by the spectral and elemental analysis. Solub |
|
Materiale compozite pe baza de PTFE si lubrifierea cu apa. I. Caracteristicile tribologice
Lorena Deleanu, Iulian Gabriel Birsan, Gabriel Andrei, Minodora Ropa, Petruta Badea
|
| This paper presents experimental results on tribological behaviour of some composites with PTFE matrix under water lubrication. The experimental work pointed out particular processes taking place in the superficial layers of the tested composites. The re |
|
Materiale poliuretanice pe baza de diizocianati alifatici utilizate pentru
izolatii pasive cu aplicatii în constructii.
Stefan Oprea, Stelian Vlad
|
| During the past decade, a lot of effort has been spent to develop strategies to mitigate the damaging effects of earthquakes. This work has been directed at both civil structures and nuclear facilities. Polyurethane elastomers (PEs) based on polyethylene |
|
Modificarea cu polimeri a bitumurilor rutiere
MIHAI DIMONIE, DOINA DIMONIE, GABRIEL VASILIEVICI, VASILICA BEICA, DORIN BOMBOȘ,
|
| In this paper are comparatively presented a few characteristics of some indigenous distillation and oxidation road bitumens. Some differences between these two bitumen types are put into evidence, some of them being of importance in the case of the modifi |
|
Polisilani cu functiuni reactive Si-H
Liviu Sacarescu, Ionel Mangalagiu, Mihaela Simionescu, Gabriela Săcărescu, Rodinel Ardeleanu
|
| Using the well known Wurtz coupling technique in heterogenous system, polyhydrosilanes copolymers with diphenyl sequences were synthesized. This work describes the possibility to maintain stable Si-H group and to obtain functional polysilanes. Also, the |
|
Simularea si optimizarea fluxului de procesare a unor deseuri
GEORGE DRAGOI, STEFAN FUNAR, MIHAI SOLEA, COSTEL EMIL COTEȚ
|
| The efficiency of a companys activity can be estimated as referring to permanently updated BAT references. As a general rule, according to this quantifying system, the waste reduction at the enterprise level is a must. In Romania this methodology is poor |
|
Studii privind cinetica cracarii termice a deseurilor
de polietilentereftalat
DORIN STANICA-EZEANU
Universitatea Petrol-Gaze Ploiesti, Bdul. Bucuresti, Nr. 39, 100680, Ploiesti, România
|
| The aim of this study is to calculate the kinetic parameters for thermal cracking of waste PET in presence of radical donors. The thermal decomposition of PET is carried out at different temperatures (693-773 K), high pressure and by using heavy paraffini |
|
Acoperiri organice pe bază de vopsele pulbere
I. Vopsele pulbere termoplastice
MIHAI RUSU, PETRONELA CATALINA MINDRILA, CARMEN ELENA MOCANU |
Coating powders are finely grounded polymeric materials containing binders, pigments, extenders and special additives, used to obtain decorative and protective organic coatings. There are two major categories: thermoplastic and thermoreactive coating po |
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Bismaleinimida - agent de prevenire a proceselor distructive
MARIA GIURGINCA, LIVIA POPA |
| This paper presents data concerning the capacity of a bismaleinimide (BMI) to protect elastomers with different structures and unsaturated degree and the copolymers EVA submitted to thermooxidative destruction at 80 - 200șC. The main structural changes we |
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Cinetica consumarii unor antioxidanti fenolici
la termooxidarea LDPE
VASILE DINOIU, LAURA MONICA GORGHIU, ION MIHALCEA, SILVIU JIPA, TRAIAN ZAHARESCU, RADU SETNESCU, CRINELA DUMITRESCU, RADU OLTEANU |
| The kinetic approach on thermal stabilization of LDPE in the presence of 7 chalcone compounds is presented. The application of zero order or first order treatment to the experimental date obtained for stabilized LDPE has revealed that the depletion of ant |
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Consideratii privind compatibilitatea unor structuri
de cauciuc cu deseuri din piele
SANDA VISAN, VIRGINIA CIOBOTARU, GHEORGHE COARA, MARGARETA FLORESCU |
| The research investigated the compatibility between the styrene-butadiene rubber mix and wastage materials of finite cromated leather in order to obtain products necessary in various industries or specifically in the leather and shoes industry. The resear |
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Efectele intarzietorilor de flacara asupra comportamentului termic si mecanic al unor poliuretani termoplastici
STELIAN VLAD |
In this study were investigated the thermal and mechanical behavior of some polyurethane ignites by addition with nonreactive flame-retardants. Some flame-retardants, such as the compounds containing halogen, give toxic and corrosive fumes during combus |
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Heterogenizarea cu grupari pendante orto- aminobenzoice
si para- aminobenzoice a copolimerilor
stiren-divinilbenzen clorometilati
CORNELIU-MIRCEA DAVIDESCU, ADRIANA POPA |
Synthesis of orto- and para-aminobenzoic groups grafted on copolymers is described. The method is applied, extended and optimised for gel-type styrene-divinylbenzene copolymers (S-DVB) with 5' and 7' degree of crosslinking.
Keywords: orto- and para- |
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Influenta structurii chimice a polimerului acrilic
asupra proprietatilor materialului textil peliculizat
MICHAELA DINA STANESCU, SILVIA MIHUTA |
| Five commercial products, based on acrylic polymers, have been used for cotton coating. The structures of the polymers have been established based on their IR spectra of the active compound from the acrylic dispersion. The properties of the coated materia |
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Poli(succinimido-eteri) functionali
CAMELIA HULUBEI |
| New poly(succinimide-ether)s with maleimidic rings in the side chain were synthesized by a chemical modification reaction on the polymers containing hydroxylic pendant groups. The polymers were obtained in good yields and they were characterized by eleme |
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Polimeri diazobenzenici in folii si tablete. Proprietati fotocromice si dielectrice
IRINEL GRECU, MITACHI STRAT |
| Photochromic properties of copolyethers and copolyesters based on bisphenol-A 4,4-dihydroxydiphenyl, 4, 4-dihydroxy-azobenzene and 3,3-bis (chloromethyl) oxetane both embedded in a polymer matrix |
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Studii asupra comportarii reologice a unor aditivi intarzietori de priza destinati betonului pentru sonde
ANCA MOISE, ELENA CORLATEANU, CONSTANTIN LUCA |
Rheological behaviour of some products based on chemical modified starch, with characteristics proper to retarding additives for concrete designed for cementation of the big depth wells, was investigated. With that end in view, rheological tests of seve |
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Studiu critic asupra testului de dilatare a inelului la tuburi zincate
VIOREL PUIU PAUN |
| The canning of fuel elements in nuclear reactors is subjected to stress and strains, which may cause failure if the material does not possess sufficient ductility. Of particular interest is localized strain in the circumferential or transverse ductility. |
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Acoperiri organice pe baza de vopsele pulbere
VIII. Influenta agentilor de matisare
Carmen Elena Mocanu, Mihai Rusu
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| The organic coatings made with powder dyes constitute an alternative solution to liquid dyes, for thez ensure a proper equilibrium between performance, price and work protection. Depending on the utilization field, this kind of organic coatings may be rea |
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Aspecte ale comportarii reologice a esterilor acidului
o-sec-butil-fenoxiacetic
Geza Bandur, Daniela Resiga, Vasile Pode1
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| This paper investigates the rheological properties of some o-sec-butyl-phenoxyacetic esters as a function of temperature, shear rate, and type of the polyol used to prepare the ester. The curves viscosity-temperature and viscosity-shear rate in loop test |
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Caracterizarea compozitelor polimerice
pe baza de EPDM reticulat in matrice poliolefinica
SANDA VISAN, VIRGINIA CIOBOTARU, FLORICA IONESCU, PETRU BUDRUGEAC,
CONSTANTIN GHIGA
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| The samples of type EPDM (ethylene-propylene-dienmonomer) rubber and elastoplastic mixtures obtained with either polyethylene or polypropylene in various weight percentages were studied using IR spectroscopy, thermal analysis as well as optical microscopy |
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Cristale lichide polimere cu mezogen în catena principala.
Corelatii structura proprietati termotrope
Luminita Marin, Vasile Cozan, Maria Bruma
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| This paper describes the general concept on structure liquid crystalline properties relationship for main chain polymers which contain rigid rod like mesogens. The influence of the mesogenic group, flexible spacers, molecular weight and molecular weig |
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Degradarea PEjd stabilizata pe un interval de doze de iradiere de sterilizare
EUGEN Feraru, CORNELIU Podina, TRAIAN Zaharescu, SILVIU Jipa
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| The oxidability of low density polyethylene stabilized with several antioxidants was investigated by oxygen uptake. The radiosterilization doses (5, 10 and 20 kGy) were applied for characterization of antioxidant activity of calix<4>arene, Santonox R, Ion |
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Diferite tehnici de optimizare aplicate procesului
de polimerizare radicalică a stirenului
Corneliu Petrila, Silvia Curteanu
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| This paper deals with the multiobjective optimization problem, applied to the free radical polymerization of styrene. The objectives taken into account and proportionally combined into a scalar objective function are: maximization of the monomer conversio |
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Modelul de regresie al polimerizarii solutiei anionice a-metilstiren cu un initiator pe baza de n-butil-litiu
Emil Buzdugan, Herbert Koch, Horia Iovu, Lorena Iancu, Sorina-Alexandra Garea, Paul Ghioca, Georgeta Masson
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| By replacing polystyrene hard blocks with poly-á-methylstyrene ones, the service temperature of thermoplastic elastomers can be considerably enhanced, because the glass transition temperature of the latter is about 170°C. The thermodynamics of polymerizat |
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Pelicule subtiri de politiofen-polipirol multi-stratificate depuse prin polimerizarea plasmei
Florin Nastase, Claudia Nastase, Livia Maria Constantinescu, MIRCEA Bercu, Ioan Stamatin
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| There were obtained simple thin films of polypyrrole (PPy) and polythiophene (PTh) and double layer films polypyrrole / polythiophene (PPy/PTh) on silicon substrate from deposition in DC plasma reactor. The films obtained were characterized by FT-IR spect |
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Poliesteri reticulabili
CAMELIA Hulubei
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| New polyesters with maleimide pendent groups have been synthesized by direct solution polycondensation reaction between 4-42 - dihydroxy- biphenyl and two functional bismaleimides containing carboxylic functionalities. The products were characterized b |
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Polimerizarea radicalica prin transfer de atomi. I. Date generale
Mircea Teodorescu
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| Controlled/living radical polymerization (CLRP) is a field that has been expanding continuously during the last 15 years, as the method allows for the synthesis of well-defined polymers under mild conditions. Many CLRP systems have been developed, all of |
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Posibilitati de marire a debitului extruderului
cu un melc de geometrie data
COSMIN V. JINESCU
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| The ways leading to the increase of the flowrate of an extruder of a given geometry are examined, while considering the real situation: screw is rotating and the barrel is stationary; the granules slide onto the surface of the screw; in the granules rela |
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Prepolimeri poliaminobismaleimidici-rasini epoxidice modificate folosite in compozitii termic stabile
Constantin Gaina, Viorica Gaina, Cristi V. Grigoras
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| The possibility of obtaining thermally stable epoxy compositions by modifying composition of epoxy resins at 100-130°C with 6-20 phr 1,1-(methylene-1,4-phenylene)bismaleimide and using 9-10 phr 4,4-diaminodiphenylmethane as curing agent was studied. The |
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Reactii Wittig-Horner pe suporturi tip stiren-divinilbenzen
în conditiile catalizei prin transfer interfazic
2. Utilizarea fosfonatilor grefati
Adriana Popa, Gheorghe Ilia, Smaranda Iliescu, Aurelia Pascariu, BIANCA Maranescu
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| The Wittig-Horner reaction is one of the most important reactions in organic chemistry for obtaining alkene. Phase transfer catalyzed reactions are often more easily and cheaply carried out than conventional methods. The copolymer functionalized with diet |
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Simularea injectarii unei cupe cotiloide folosind analiza cu elemente finite
Catalin FETECAU, Felicia STAN, Catalin POPA
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| In this paper the numerical simulation of the injection moulding of the total hip prosthesis (acetabular) cup made of UHMWE is carried out in order to determine the optimal conditions for injection process parameter. The numerical simulation was performed |
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Studii preliminare in vederea obtinerii si caracterizării polimerilor cu substituenti azoici
IONICA IONITA, CORNELIU TARABASANU-MIHAILA, EDINA RUSEN, CRISTIANA RADULESCU,
ANA-MARIA HOSSU, ELENA IRINA MOATER
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| Photochromic compounds are able to change their absorption spectra when exposed to light or dark condition. This process is reversible when the photochromic moieties exist, as usually occurs, in two different forms, whose relative concentration depends on |
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Terpentina folosita drept materie prima chimica in procesele de polimerizare
CONSTANTIN N. CASCAVAL, CONSTANTIN CIOBANU, LILIANA ROSU, DAN ROSU
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| Turpentine from pine trees is a renewable source of materials used as feedstock by the chemical industry. The paper presents some ways to use turpentine in the polymer chemistry for preparation of polyterpenes, adhesives, copolymers based on the main comp |
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Polimerizare radicalica cu transfer de atomi. II. Aplicatii
Mircea Teodorescu
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| Atom transfer radical polymerization (ATRP) is one of the most versatile controlled/living radical polymerization (CLRP) method for the production of well-defined materials. As a consequence, ATRP has been employed for the synthesis of a large variety of |
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Aplicatii ale cauciucului siliconic la turnarea
centrifugala a aliajelor de ZnAl.
CATALIN FETECAU, MANUEL SAN JUAN BLANCO, FELICIA STAN, STEFAN MIHAILA
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| The paper presents some technological aspects related to a new procedure for centrifugal casting in moulds made of silicone rubber. The procedure has been enhanced by the American company Tekcast Industries Inc. and is applicable for the casting of plasti |
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Aspecte referitoare la sinteza si caracterizarea unor
tipuri de poliuretani termoplastici
CONSTANTIN BOLCU, FLORIN BORCAN, REMUS NUTIU
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| This paper contains the results of an experimental research regarding the synthesis of some types of thermoplastic polyurethane based on 1,6-hexanedyol polyadipate (PAH), 1,4-buthanedyol and ethyleneglycol polyadipate (PABE) and ethyleneglycol polyadipate |
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Caderea de presiune la curgerea neizoterma a topiturilor
polimerice prin canale
Mariana-Florentina Stefanescu
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The paper develops a method based on the thermal effects caused by pressure drop, internal friction, external friction and convection, for polymer melts pressure drop calculation in non isothermal melt flow through the channels. The whole thermal effec |
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Cercetari privind realizarea
imbinarilor unor suporturi elastomerice polare vulcanizate cu compozitii adezive pe baza de
elastomeri polari nevulcanizati
Ioana Dusescu, Ioan Liviu Dan, Paul Octavian Stanescu, Camelia Hodosan, Gheorghe Hubca
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| In the previous article <1>, results concerning the bonding of cured non-polar elastomers supports with adhesive formulations based on non-cured non-polar elastomers have been presented. This research is dedicated to obtain additional information regardin |
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Consideratii asupra ecuatiilor constitutive folosite
la studiul maruntirii deseurilor din cauciuc armate
cu insertie metalica
Dan Dobrota
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| The paperwork presents the principal constituent equations used on study of mincing rubber waste reinforced with metalic insertion. These equations permit a study of mincing process on analytical ground, without being necessary, in some cases, to conduct |
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Fenomene tranzitorii in retelele de gaze naturale
din conducte de polietilena
CORNEL Trifan, SORIN NEACSU, MIHAI ALBULESCU
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| This paper proposes a genuine mathematical pattern for the study of the unsteady phenomena that characterize the working out of natural gas polyethilene pipeline networks. The calculation programme elaborated on the basis of the mathematical model allows |
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Influenta poliolefinelor asupra caracteristicilor
elastomerilor termoplastici pe baza de elastomer
etilen propilen terpolimer maleinizat
Maria Daniela Zuga, Corneliu Cincu
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| The influence of propylene, polyethylene and maleinized polyethylene on the characteristics of thermoplastic elastomers based on maleinized ethylene-propylene terpolymer rubber was investigated. As the amount of the added polyolefine is increased, the har |
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Metoda permeabilitatii vaporilor de apa
aplicata materialelor poroase hidrofile
Eduard GATIN, Dan ALEXANDREANU, Cristina MIRON
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The article presents a study for water vapours permeability and diffusion properties for two hydrophilic materials, used for soft contact lens manufacturing. The materials have been investigated according to DIN 52615, German Standard. The technological |
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Modelarea matematica a sudurii cap la cap cu element incalzitor a tevilor din polietilena utilizate in industria chimica in vederea optimizarii parametrilor de sudare
MIHAELA POPESCU, VERONICA ARGESANU
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| For the transport of gas or water, it is generally welding by heater which is used for the butting together of the tubes. The quality of the joint is influenced by the choice of the parameters of welding, the geometry of the tubes and the environment. It |
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Modelarea tridimensionala a paletei de antrenare a substantelor folosite pentru generarea spumei umede din lichide
Alina Spanu, Anton Hadar, George Dragoi
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| In order to test the presence of some chemical substances within the composition of specific liquids and fluids, such as cosmetics, beverages, hydraulic oil, it is absolutely necessary to measure the foam level as a quality condition for selling them on t |
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Polimeri aromatici sulfonati
Corneliu Hamciuc, Elena Hamciuc
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| This article presents literature data regarding the synthesis and properties of some sulfonated aromatic polymers, such as polyethersulfones, poly(etherketone)s, polybenzimidazoles, polyimides, which can be used for proton-exchange membrane in fuel cell |
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Proprietati de utilizare a unor amestecuri
PVC-poliuretan termoplastic realizate prin modificare fizica
Doina Dimonie, CATALIN Zaharia, Teodora Zecheru, DENIS PANAITESCU1, Ioana Vasile
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| A recyclable material, that can be incinerated under safety conditions, for humans and environment, the polyvinyl chloride (PVC) is still a largely used polymer, as a compound, inclusively. The PVC -TPU compounds are of interest due to their attrition r |
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Proprietatile copoliesterilor
poli Ő-caprolactonei hiper-ramificate
Mihaela Ursu, Ingo Neuner, Ralf Thomann, Mihai Rusu, Holger Frey
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| Hyperbranched poly (e-caprolactone) copolyesters (hb-PCL) have been prepared by combination of ring opening polymerization (ROP) of e-caprolactone (e-CL) as cyclic AB monomer and concurrent polycondensation of 2,2´-bis(hydroxymethyl)butyric ac |
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Sinteza unor monomeri acrilici continand
brom utilizati ca agenti radioopacifiere a cimenturilor acrilice
MARIUS CIPRIAN RUSU, MIHAI RUSU, MARCEL Popa, CHRISTELLE DELAITE, GERALD REISS
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| We synthesized and characterizated two bromine containing monomers, 2-(2-bromopropyloxy) ethyl methacrylate (BPEM) and 2-(2-bromoisobutyriloxy) ethyl methacrylate (BIEM), to be used as radiopaque agents in acrylic bone cements. Using methyl methacrylate |
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Studii asupra unor amelioratori ai viscozitatii pentru uleiuri multigrad.
2. Comportamentul reologic al solutiilor concentrate
IOANA STANCIU, MINODORA LECA
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| Rheological measurements of 3; 6; 10 and 12% INFINEUM SV 260 solutions in SAE 10W mineral oil show non-Newtonian behaviour in the temperature range 313-370 K and shear rates ranging between 3 and 1312 s-1: they follow the Bingham model at low concentratio |
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Studiu comparativ asupra radiotermoluminescentei
unor polimeri
SILVIU JIPA, DIANA ILIE, SORIN ILIE, RADU SETNESCU1, WILHELM KAPPEL
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| A survay on the radiothermoluminescenceof 25 polymers is presented. The RTL glow curves were recorded on the temperature range starting from 77 K up to room temperature after 60Co irradiation. The most RTL peaks occur at temperatures similar to those assi |
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