bluuebunny/crossref_metadata_2025 huggingface dataset:
Binary copolymerizations of N‐acryloyloxyphthalimide with methyl acrylate, methyl methacrylate and acrylonitrile
Authors: Shaaban A. F. , Khalil A. A. , Messiha N. N.
Published: April 2003

N‐Acryloyloxyphthalimide was prepared by the reaction of acrylic acid with N‐hydroxyphthalimide in the presence of N,N′‐dicyclohexylcarbodiimide. The monomer reactivity ratios for the copolymerization of N‐acryloyloxyphthalimide with methyl acrylate, methyl methacrylate, and acrylonitrile, respectively, were estimated by 1H‐NMR spectroscopic data. The Q‐ and e‐ values for N‐acryloyloxyphthalimide were calculated.
Über die Eigenschaften von Poly(p‐phenylen‐1,3,4‐oxadiazol)‐Lösungen in Konzentrierter Schwefelsäure. 1. mitt. strukturen in konzentrierten lösungen
Authors: Schelle H. , Hofmann D. , Weigel P.
Published: April 2003

Die Lösungseigenschaften von Poly(p‐phenylen‐1,3,4‐oxadiazol) (POD) in konzentrierter H2SO4 werden auf der Basis einer Literaturübersicht und eigener experimenteller Arbeiten beschrieben. In konzentrierten POD‐Lösungen (Polymergehalt ≧ 15 Masse‐%) bilden sich kristalline Strukturen mit sphärolithischer Morphologie, die der von MILKOVA beschriebenen Kristallsolvatmodifikation zugeordnet werden.
On the thermal degradation of poly(vinyl chloride). Synergistic effect of mixtures of lead and zinc carboxylates
Authors: Odilora C. A.
Published: April 2003

The effect of a mixture of lead and zinc carboxylates on the thermal decomposition of poly(vinyl chloride) in air is studied. The results obtained by weight loss determination and IR and UV spectroscopic analysis showed a marked influence of these compounds on the degradation of PVC. The greatest stabilization was achieved with lead dodecanoate. With a mixture of lead octadecanoate and zinc octadecanoate an indication of synergism was observed leading to enhanced stabilization. With the mixture of lead and zinc dodecanoate the level of stabilization was less; this mixture catalysed the degradation of PVC at 473 K. The mechanism of the stabilization of PVC by the studied compounds is discussed.
Einfluß der thermischen Vorbehandlung auf die Änderung der Eigenschaften von Polymermischungen
Authors: Loev A. M. , Zadorina E. N. , Zelenev Ju. V.
Published: April 2003

Die physikalische Modifizierung von Polymeren unterschiedlicher Klassen durch thermische Behandlung wird mit Hilfe einer mehrparametrigen Zustandsgleichung beschrieben. Die Ergebnisse einer Untersuchung des Einflusses der thermischen Behandlung von Polymeren bei kontinuierlicher und stufenweiser Erwärmung und Abkühlung werden diskutiert.
Influence of the initial polyethylene structure on the modification with styrene and polystyrene
Authors: Milczarek P. , Pluta M. , Kryszewski M.
Published: April 2003

The influence of the initial polyethylene structure on the effects of modification with styrene and polystyrene is investigated. It is shown that the effectivity of modification is basically governed by the nature of the crystalline and amorphous phases in polyethylene. The polystyrene phase included into the polyethylene matrix changes its mechanical properties in dependence on the origin of the amorphous phase of the polyethylene. The main differences between annealing of low density polyethylene and the modification presented in this work are pointed out.
Ultraschall‐ und DSC‐Untersuchungen zur Temperaturabhängigkeit des Härtungsprozesses von Diandiglycidether
Authors: Alig I. , Häusler K. G. , Nancke K. , Domaratius E. , Fedtke M.
Published: April 2003

Die Ultraschallgeschwindigkeit und die Utraschallabsorption von Diandiglycidether wurden bei verschiedenen Härtungstemperaturen im Bereich von 60 bis 130°C in Abhängigkeit von der Härtungszeit gemessen. Aus den Härtungszeitkurven konnte die Gelzeit, das Durchlaufen des dynamischen Glasübergangs und die Endphase der Härtung bestimmt werden. Eine ARRHENIUS‐Darstellung dieser charakteristischen Zeiten und der Härtungstemperatur erlaubt eine umfassende Charakterisierung der Härtungskinetik des Systems. Für T < 100°C tritt eine Reaktionsbeschleunigung mit wachsender Härtungstemperatur auf. Das Absinken der Reaktionsgeschwindigkeit für T > 100°C wird mit einer Spaltungsrcaktion bei höheren Temperaturen erklärt. Die bei niederen Temperaturen gehärteten Netzwerkc weisen eine perfektere Netzwerkstruktur auf. Mittels DSC während der Härtung bestimmte Tg‐Zeit‐Kurven für verschiedene Härtungstemperaturen liefern analoge Resultate.
Thermal properties of copolymers of alkyl methacrylates with triallyl cyanurate
Authors: Ryttel A.
Published: April 2003

The homo‐ and copolymers of triallyl cyanurate and methyl methacrylate, ethyl methacrylate, propyl methacrylate, n‐butyl methacrylate, and cyclohexyl methacrylate were synthesized by free radical bulk polymerization using benzoyl peroxide as the initiator. The thermal properties of the polymers have been studied. The influence of the triallyl cyanurate content on the thermal behaviour of the copolymers has been investigated.
Preparation and characterization of carboxymethyl carobin
Authors: Ragheb A. , Haggag K. , Abd El‐Thalouth I.
Published: April 2003

Carboxymethyl carobin samples of different degrees of substitution were prepared from carobin by reaction with monochloroacetic acid in presence of sodium hydroxide in non‐aqueous medium. The derivatives are water‐soluble. Their pastes in water are characterized by non‐Newtonian pseudoplastic behaviour. The apparent viscosity depends on the degree of substitution. The stability of the products at storage increases with increasing degree of substitution.
Studies on the graft copolymerization of methyl methacrylate onto starch
Authors: Okieimen F. E. , Said O. B.
Published: April 2003

Methyl methacrylate was grafted onto starch by the ceric ion method with and without removing of the unabsorbed ceric ions. Graft level, molecular weight of the grafted chains, and number of the grafted chains were measured in dependence on ceric ion concentration. On base of the results the mechanism of the grafting reaction is discussed.
Structure of amorphous cellulose
Authors: Paakkari T. , Serimaa R. , Fink H.‐P.
Published: April 2003

The structure of well ground cellulose I and cellulose II samples was studied by measuring the X‐ray scattering intensities and calculating the corresponding radial atomic density functions (RDFs). Experimentally obtained results have been compared with model calculations mainly varying the packing of nearest neighbour chain segments. It was found that the local packing of chain segments is the same for both cases of milled samples and resembles that of crystalline cellulose II.
Thermomechanische Untersuchungen an Epoxid/Amin‐Carbonsäure‐Hybridnetzwerken
Authors: Klee J. , Flammersheim H.‐J. , Utschick H.
Published: April 2003

An neuen durch Polymerisation von carbonsäuremodifizierten DGEBA/Anilin‐Prepolymeren erhaltenen Hybridnetzwerken wurden thermomechanische Untersuchungen (E‐Modul, tan δ, Tg) durchgeführt. Mit steigender Glasübergangstemperatur nimmt tan δ ab, während das Verhältnis der bei 30°C und 130°C gemessenen E‐Moduln mit wachsender Molekülmasse der Netzwerkbögen ansteigt. Weiterhin wurden die Biegefestigkeit, die Härte (Kegelfließpunkt) und die Ausdehnungskoeffizienten ermittelt.
Synthesis of regular polyampholytes by copolymerization of maleic acid with allyl and diallyl amine derivatives
Authors: Hahn M. , Jaeger W. , Schmolke R. , Behnisch J.
Published: April 2003

Radical copolymerization of maleic acid with allyl amine or diallyl amine derivatives results in regular polyampholytes which are completely or to high extent soluble in water. With equimolar amounts of both comonomers the rate of the alternating copolymerization runs through a minimum. The copolymers are thermally relatively stable and can be changed to water insoluble products by tempering.
Synthesechemische Modifizierung von Cellulose zur Einführung aktiver funktioneller Gruppen unter heterogenen Reaktionsbedingungen. Fortschrittsbericht
Authors: Schnabelrauch M. , Heinze T. , Klemm D.
Published: April 2003

Die vorliegende Übersicht enthält eine zusammenfassende Darstellung von Untersuchungen zur Einführung reaktiver funktioneller Gruppen in die Cellulose. Unter synthesechemischen Gesichtspunkten werden heterogen verlaufende Reaktionen betrachtet, die sich vor allem durch die Erzielung eines möglichst hohen durchschnittlichen Substitutionsgrades, einen weitgehend selektiven Verlauf oder die Anwendung neuer präparativer Techniken und Reagenzien auszeichnen.
Catalytic degradation of polyolefines under the action of Friedel‐Crafts catalysts in solution. 1. Some new features of catalytic degradation of poly(isobutylene)
Authors: Khalafov F. R. , Novrusova F. A. , Ismailov E. G. , Krentsel B. A.
Published: April 2003

The catalytic degradation of poly(isobutylene) under the action of AlBr3 and AlEtCl2 in aliphatic solvents was studied at 20 to 60°C, and the kinetic features of the process were established. The investigation of the influence of 2,6‐di‐tertbutylpyridine showed its indifference towards the degradation process, while O2, p‐benzoquinone, and tetracyanoethylene have an inhibiting effect. On the basis of EPR studies the posibility of a radical chain mechanism of the degradation reaction could be shown.
Herstellung, Struktur und Anwendung von ionotropen Gelen aus carboxygruppenhaltigen Polysacchariden. Fortschrittsbericht
Authors: Heinze T. , Klemm D. , Loth F. , Philipp B.
Published: April 2003

Die vorliegende Übersichtsarbeit behandelt die Bildungsweise, die chemische und morphologische Struktur und die wesentlichen Anwendungsmöglichkeiten von ionotropen Gelen auf Basis natürlicher, biotechnologisch gewonnener und chemisch modifizierter Polysaccharide mit Carboxyfunktionen als anionischen Gruppen. Schwerpunkte sind dabei die Wechselwirkung zwischen den Carboxygruppen und den mehrwertigen Metallkationen und die Selektivität dieser Wechselwirkung, die Morphologie ionotroper Kapillargele einschließlich der Modellvorstellungen zu ihrer Bildung sowie die Anwendung solcher Gele zur Zell‐Immobilisierung und kontrollierten Wirkstoff‐Freisetzung.
Phase separation in poly(p‐phenylene terephthalamide)/polyamide 6 blends
Authors: Kammer H.‐W. , Kummerlöwe C.
Published: April 2003

The phase behaviour of blends of the rigid‐rod polymer poly(p‐phenylene terephthalamide) and the flexible‐coil polymer polyamide 6 and that of the ternary system of both polymers and sulfuric acid were studied. Forced mixtures of both incompatible polymers can be obtained by rapid coagulation of ternary solutions below their critical concentration. These blends undergo phase separation during thermal treatment. Different phase separation structures were obtained and discussed in terms of different mechanisms of unmixing. The phase separation temperatures and the melting points of the blends were measured.
Copolymerization of alkyl methacrylates with N‐Vinyl carbazole. Determination of reactivity parameters
Authors: Ryttel A.
Published: April 2003

The copolymerization of ethyl methacrylate and n‐butyl methacrylate with N‐vinyl carbazole was studied in bulk at 333 K using benzoyl peroxide as initiator. The reactivity ratios of the monomers were determined by the FinemanRoss and Kelen‐Tüdős methods and briefly discussed. The Alfrey‐Price Q and e values of methacrylates were evaluated.
The rate of batch emulsion polymerization of vinyl chloride
Authors: Boieshan V.
Published: April 2003

The rate of batch emulsion polymerization of vinyl chloride is described by the equation

where E is the overall activation energy. The reaction order with respect to the initiator, γ, depends on the type of the termination reaction; the reaction order with respect to the emulsifier, β, depends on the chemical nature of the emulsifier and on the amount of adsorbed emulsifier on the latex particles. The values of the coefficients and of the activation energy are determined for two initiation systems and two types of emulsifier.
Kinetics of the polyaddition reaction of 2,4‐tolylene diisocyanate with macrodiols catalyzed by tinorganic‐tertiary amine systems
Authors: Sojecki R.
Published: April 2003

The influence of tinorganic catalysts and catalytic systems of a tinorganic compound and a tertiary amine on the polyaddition reactions of 2,4‐tolylene diisocyanate with macrodiols is investigated. The reaction rate constants were calculated using an integral‐differential method on the basis of concentration changes of the NCO groups determined by a chemical method. A synergetic effect of the tinorganic compound and the tertiary amine in the catalytic system was observed.
Homo‐ und Copolymerisation von Butadien und isopren mit Ni/Ti/Al‐ und Ni/B/Al‐Katalysatorsystemen. II. Butadienhomopolymerisation
Authors: Gebauer U. , Oberdörfer A. , Gehrke K.
Published: April 2003

Bei der Butadienpolymerisation mit dem Katalysatorsystem Nioct./TiCl4/AlEt3 wurde der Einfluß der Konzentration der Katalysatorkomponenten auf die Ergebnisse der Polymerisationsreaktion untersucht. Weiterhin wurde über eine Variation wichtiger Reaktionsparameter ([M], [I], tp) deren Auswirkung auf die Polymerisationsaktivität, die Molmasse und die Mikrostruktur der synthetisierten Polymere ermittelt. Weitergehende Aussagen wurden durch die Ermittlung charakteristischer kinetischer Reaktionsgrößen möglich. Somit konnte ein Vergleich mit der entsprechenden Butadienpolymerisation mit dem Katalysatorsystem Nioct./BF3. Et2O/AlEt3 erfolgen.
WAXS investigations of the supermolecular structure of high modulus gel spun/hot drawn polyethylene fibres
Authors: Hofmann D. , Schulz E. , Walenta E.
Published: April 2003

The supermolecular structure of some commercial and laboratory made high modulus gel spun/hot drawn PE fibres is characterized by WAXS, SAXS, EM, and mechanical methods. Fibrillar and shish‐kebab morphologies have been found. The structure parameters are compared with those obtained for surface grown high modulus PE fibres and correlated with the axial Young's modulus of the samples. The deformation process during hot drawing of PE gel fibres is discussed.
Methoden zur charakterisierung von strukturumwandlungen bei der thermisch‐oxidativen stabilisierung von pan‐fasern
Authors: Fink H.‐P. , Walenta E. , Frigge K. , Büchtemann A. , Weigel P.
Published: April 2003

Im Kohlenstoffaser‐Herstellungsprozeß werden Filamente auf Basis Poly(acrylnitril) durch eine Wärmebehandlung stabilisiert, wobei komplexe physikalische und chemische Strukturveränderungen des Precursormaterials auftreten. Die kombinierte Anwendung der Methoden DSC und Schrumpfkraftmessung, IR‐ und 13C‐CP/MAS‐NMR‐Spektroskopie sowie Röntgenweit‐ und Röntgenkleinwinkelstreuung ermöglicht eine detaillierte Untersuchung der vielschichtigen Strukturveränderungen und liefert damit die Grundlagen für eine Optimierung des Stabilisierungsprozesses.
Polyaromaten mit fasertextur – die modernen hochleistungs‐carbonfasern
Authors: Fitzer E.
Published: April 2003

Die heutigen Hochleistungs‐Carbonfasern bestehen überwiegend aus stickstoffhaltigen Polyaromaten mit struktureller Vorzugsrichtung. Der Chemismus der Cyclisierung, Dehydrierung und Oxidation von Poly(acrylintril)‐Fasern zu dem sauerstoff‐ und stickstoffhaltigen Leiterpolymer wird im einzelnen diskutiert. Alle Herstellungsstufen sind verfahrenstechnisch so gestaltet, daß die im Polymer vorgebildete Fasertextur erhalten bleibt. Der weitere thermische Abbau dieser Leiterpolymere zu den einzelnen Stufen mit unterschiedlichem Stickstoffgehalt wird beschrieben. Dabei tragen neben der chemischen Analyse Ergebnisse der Ramanspektroskopie und der Transmissionselektronenmikroskopie zum Verständnis des Übergangs vom Polymer zur Carbonfaser und des Einflusses der einzelnen Prozeßparameter auf die mechanischen Eigenschaften bei.
Neue leistungsfähige werkstoffe und fasern auf der basis von thermotropen flüssigkristallinen hauptkettenpolymeren (TLCP)
Authors: Rätzsch M. , Pospiech D.
Published: April 2003

Einleitend werden die aus den bisherigen internationalen Ergebnissen bei der Entwicklung thermotroper flüssigkristalliner Hauptkettenpolymere (TLCP) resultierenden und verallgemeinerten Erkenntnisse zusammengefaßt. Anschließend werden der gegenwärtige Stand der Kommerzialisierung, die Legierungsbildung und ein Vergleich der TLCP mit anderen Hochleistungspolymerwerkstoffen und einigen Buntmetallen beschrieben. Im zweiten Teil wird das Konzept der vorgesehenen Entwicklungen begründet und experimentelle Ergebnisse bei der Synthese der Poly(ethylenterephthalat)/p‐Hydroxybenzoesäure‐Copolyester (PETP/p‐HBA) und vollaromatischer Copolyester auf der Basis von p‐HBA/Resorcinol/Terephthalsäure und p‐HBA/Isophthalsäure/Hydrochinon vorgestellt. Die Zielrichtungen für weiterführende Untersuchungen werden kurz diskutiert.
Relaxationsströme in hochohmigen polymeren
Authors: Hänsel H.
Published: April 2003

Elektrische Relaxationsprozesse und ihr Einfluß auf die Messung von Strom‐Spannungs‐Charakteristiken von hochohmigen Polymeren werden beschrieben. Die Möglichkeiten, durch Untersuchung der Relaxationsprozesse Informationen über Polarisations‐ und Raumladungserscheinungen zu erhalten, werden diskutiert und an Hand einiger Beispiele demonstriert.
Oligomercharakterisierung bei der Strukturbildung diolmodifizierter Epoxide mittels GPC, FTIR und 13C‐NMR
Authors: Schlothauer K. , Müller G. , Fedtke M.
Published: April 2003

Mittels GPC, FTIR und hochauflösender 13C‐NMR wurden Lösungen sowie niedermolekulare Fraktionen der bei der Heißhärtung von Epoxiden auf der Basis von Bisphenol‐A‐Diglycidethern (BADGE) mit Butan‐1,4‐Diol (BD) in Gegenwart von Mg(ClO4)2. 2H2O als Beschleuniger entstehenden Reaktionsprodukte untersucht und Aussagen über die Strukturbildung getroffen.
On the determination of the molecular weight distribution of poly(dimethyl diallyl ammonium chloride) by ultracentrifugation
Authors: Timofejeva G. J. , Pavlova S. A. , Wandrey Ch. , Jaeger W. , Hahn M. , Linow K.‐J. , Görnitz E.
Published: April 2003

Molecular weight distributions of poly(dimethyl diallyl ammonium chloride) were determined from sedimentation velocity measurements. After a presentation of the experimental basis for the evaluation of distribution curves, molecular weight distribution curves for different samples were discussed and compared with results of solution fractionations and kinetic‐mechanistic investigations.
Poly(methacryloyloxyalkylenoxybenz‐4‐′‐substituierte‐anilide)
Authors: Ruhmann R. , Rübner J. , Rodekirch G. , Zschuppe V. , Gnauck R. , Netopilik M. , Wolff D.
Published: April 2003

Synthese und Eigenschaften einiger Poly(methacryloyloxyalkylenoxybenzoesäure‐4′‐subst.‐anilide) werden beschrieben. Das Ziel der Synthese, Polymere mit flüssigkristallinen Eigenschaften zu erhalten, wird insbesondere durch Copolymerisation mit anderen Methacrylaten erreicht.
Influence of cooling conditions on the structure and properties of high‐speed spun polypropylene fibres
Authors: Diačik I. , Diačik I. , Jambrich M.
Published: April 2003

The influence of blasting speed of cooling air on the structural parameters and physical properties of polypropylene fibres spun with take‐up speeds of 1000 to 5000 m/min is investigated and discussed.
Polyesterification of 1,3‐di(carboxymethoxy)benzene with tetraethylene glycol
Authors: El‐Safty M. A. , Shaaban A. E. , Moustafa H. Y.
Published: April 2003

The polyesterification of 1,3‐di(carboxymethoxy)benzene with tetraethylene glycol in both equimolar and nonequimolar ratios has been studied over the range of 120 to 160°C in the absence and in the presence of p‐toluenesulphonic acid as catalyst. The experimental results for uncatalyzed reactions agreed quite well with the kinetic equations proposed by Flory. The kinetic equations for acid catalyzed reactions, however, are in agreement with the kinetic equation proposed by Lin and Hsieh. The rate constants and activation energies for the uncatalyzed and acid catalyzed reactions were calculated.
Kinetical structural model for the network build‐up during the reaction of cyanic acid esters with glycidyl ethers. 2. Application of DCBA/DGEBA‐systems
Authors: Bauer J. , Bauer M.
Published: April 2003

The previously published kinetical structural model is applied to the network build‐up during the coreaction of 2,2‐bis(4‐cyanatophenyl) propane with 2,2‐bis(4‐glycidyloxyphenyl) propane in bulk. The relative rate constants of the main reactions, which act as the free parameters of the model, were identified for this case, and the good agreement between theory and experiment is shown.
Grafting of acrylamide onto guar gum with the redox system Cu2+/Na2S2O5
Authors: Bajpai U. D. N. , Jain A. , Bajpai A. K.
Published: April 2003

The grafting of acrylamide onto guar gum in aqueous medium initiated by the redox system Cu2+/Na2S2O5 in presence of oxygen has been studied at the temperature 35°C. The effect of the concentration of the components of the grafting system and of the reaction temperature has been determined. A plausible mechanism of the grafting process is suggested.
Biologisch abbaubare Polymere. 2. Mitt.: Zur Homo‐ und Copolymerisation von D,L‐Dilactid
Authors: Rafler G. , Dahlmann J.
Published: April 2003

Die Ringöffnungspolymerisation des D,L‐Dialactids bzw. einer äquimolaren Dilactid/Digglycolid‐Mischung wurde in Gegenwart von Sn‐II‐octoat untersucht. Umsatz und Molmasse werden nicht nur durch die Kinetik der primären Ringöffnungsreaktion, sondern auch durch Intensität und Ausmaß von Folgereaktionen der reaktiven Gruppen des gebildeten Polyesters determiniert. Parallel zur Polymerbildung laufen inter‐ und intramolekulare Umesterungsreaktionen binnenständiger Estergruppen untereinander bzw. mit Endgruppen sowie irreversible Thermolysereaktionen ab.
Kinetics and mechanism of the emulsion polymerization of vinyl acetate by redox initiation
Authors: Badran A. S. , Shendy S. M. M.
Published: April 2003

The emulsion polymerization of vinyl acetate initiated by the redox system potassium persulfate‐salieylaldehyde sodium bisulfite with poly(vinyl alcohol) as emulsifier has been studied at different reaction conditions. The rate equation for the polymerization process is established and discussed.
Zur Verknüpfung von Siloxanen mit Epoxidharzen. 2
Authors: Schickert P. , Heller A. , Rühlmann K.
Published: April 2003

Das Aushärtungsverhalten von Gemischen eines Methylphenylsiliconharzes und eines Phenolnovolak‐Epoxidharzes mit Al(acac)3 als Katalysator wurde anhand von Gelzeit‐ und DSC‐Messungen charakterisiert. Aus dem Zusammenhang zwischen Gelzeit, Härtungsbeginn, spezifischer Reaktionsenthalpie und der Zusammensetzung der Gemische wird geschlossen, daß zum Beginn der Härtung bevorzugt Reaktionen von Silanolgruppen mit Oxiran‐Resten, bei der weiteren Vernetzung jedoch in hohem Maße auch Umsetzungen von alkoholischen OH‐Gruppen mit Epoxid‐Resten ablaufen. Es werden Hinweise für die optimale Zusammensetzung von Silicon‐Epoxidharz‐Bindemitteln und für geeignete Verarbeitungstemperaturen gegeben.
Condensation polymers based on acenaphthene derivatives
Authors: Korhsak V. V. , Rusanov A. L. , Jedlinski Z. , Raubach H. , Palivoda A. , Bocharov S. S. , Bulycheva E. G. , Berlin A. I. , Shifrina Z. B. , Batirov I. , Shalikiani M. O.
Published: April 2003

The reactions involving acenaphthene and its derivaties resulting in the synthesis of various classes of mononmers, namely, bis(naphthalic anhydride)s, bis(acenaphthoquinone)s, bis(acenaphthylene)s, containing various bridging groups, are considered. The synthesized monomers have been shown to be applicable for the preparation of poly‐(naphthylimide)s, poly(naphthyoylenebenzimidazole)s, poly(quinoxaline)s, and poly(acenaphthylene)s combining good thermal characteristics and good processibility.
Phosphorus containing monomers, oligomers, and polymers from itaconic acid esters and dialkyl phosphites
Authors: Doseva V. N. , Borisov G.
Published: April 2003

Dialkyl esters of 2,3‐dialkoxycarbonyl propane‐phosphonic acid have been synthesized by addition of dialkyl phosphites to dialkyl esters of itaconic acid. The transesterification of these compounds with diols has been investigated with the aim to compare the reactivity of the two kinds of alkoxy groups. Unsaturated oligoesters have been synthesized by transesterification of dimethyl itaconate with ethylene glycol and diethylene glycol. Dimethyl phosphite has been added to their double bonds.
Phosphorus‐containing fire resistant polymers on the basis of cardotype bisphenols
Authors: Sh. Papava G. , Vinogradova S. V. , Kutateladze M. K. , Papava K. R. , Borisov G. , Verbanov S.
Published: April 2003

Aromatic homogeneous and mixed polyethers were synthesized on the basis of interaction of cardotype bisphenols, 4,4′‐difluorohenylsulfone and methyl‐bis(chloromethylphosphine) oxide. The presence of phosphorus atoms in the main polymer chain increases the fire resistance of these of polymers.
Kinetic and structural effects in matrix acceptor‐catalytic polyesterification
Authors: Ignatov V. N. , Vasnev V. A. , Perov A. B. , Vinogradova S. V.
Published: April 2003

The regularities of the acceptor‐catalytic copolyesterification in the presence of poly(4‐vinyl pyridine) and its low‐molecular analog γ‐picoline have been studied. The rate constant of the reaction is determined by the molecular mass of the polymer catalyst and by the concentration of the reagents.
Synthesis and investigation of the properties of aromatic polymers prepared by using samarium diiodide
Authors: Brandukova N. E. , Vygodski Ya. S. , Vinogradova S. V. , Raubach H.
Published: April 2003

New poly(α‐diketone)s were prepared by the reaction of aromatic dicarboxylic acid chlorides and samarium diiodide in tetrahydrofurane under mild conditions. The influence of the reaction conditions on the chemical structure and the properties of the resulting polymers has been studied. In a similar manne p‐fluorobenzoic acid chloride and samarium diiodide were used to obtain 4,4′‐difluorobenzil whose reaction of nucleophilic substitution with bisphenol A gave poly(ether‐α‐diketone)s.
Different unit structure of copolymers obtained by polycondensation of asymmetric monomers
Authors: Papava K. R. , Vasnev V. A. , Vinogradova S. V. , Markova G. D.
Published: April 2003

The influence of the reactivities of the functional groups of asymmetric and symmetric monomers and of the reaction conditions on the microstructure of the formed polyesters has been investigated. A quantitative estimation is presented for the different unit structure of the polycondensation interbipolyesters obtained from asymmetric monomers characterized by two types of isomers. The microstructure depends on the sequence of introduction of the comonomer units into the reaction system.
Polyaddition von Dian‐Diglycidylether mit Butin‐2‐diol‐1,4
Authors: Penczek P. , Szczepaniak B. , Rejdych J.
Published: April 2003

Die Polyaddition von niedermolekularem Dian‐Epoxidharz mit Butin‐2‐diol‐1,4 wurde bei 80 bei 130°C mit Triethanolamin als Katalysator durchgeführt. Die Reaktion verläuft ähnlich der Polyaddition der Bisphenole mit Epoxidharz bei Harzüberschuß. Als Endprodukte entstehen Diepoxid‐Oligomere, die in der Kette CC Bindungen enthalten.
Formation of molecular‐weight distribution of alicyclic polyimides in one‐ and two‐phase polycondensation
Authors: Pavlova S. A. , Timofeeva G. I. , Zhubanov B. A. , Solomon V. A. , Yu. Sapozhnikova S. , Lyakh E. N.
Published: April 2003

With the methods of sedimentation, fractionation, and viscosimetry the influence of the reaction conditions on the molecular weight distribution of alicyclic polyimides is investigated. Under homogeneous conditions the most probable distribution occurs, whilst in the case of a two‐phase system the molecular weight distribution tends to narrow in comparison with the most probable one. The obtained data are in good agreement with the theory of the two‐phase polycondensation.
Mechanism of polycondensation of polyimides
Authors: Sazanov Yu. N. , Antonova T. A. , Stepanov N. G. , Blazo M. , Toth A. , Szekei T.
Published: April 2003

Under conditions of high temperature, polyimides and their prepolymers undergo a number of chemical transformations, the most part of which relate to reaction of polycondensation. New aspects of thermal cyclodehydration in the presence of heteroaromatic compounds used as stereospecific catalysts were studied. The mechanism of thermal decarboxylation and decarbonylation of polyimides under conditions of heating in inert and self‐generating atmosphere was ascertained. A study of the polycondensation processes leading to the formation of ordered domains in polyconjugated products of high temperature thermolysis was carried out. The principal parameters of the thermochemical transformation of the polyimide structure depending on the chemical nature of the polyimide unit were determined by means of the kinetics of the structural changes of the basic fragments of polyimide series. The role of nitrogen atoms in the formation of the turbo‐straticulate centres in the products of polyimide thermolysis is discussed.
Synthesis of new poly(phenylquinoxaline‐ester‐imide)s
Authors: Bruma M. , Sava I. , Hamciuc C. , Simionescu C. I. , Belomoina N. M. , Babich S. A. , Krongauz E. S.
Published: April 2003

New poly(phenylquinoxaline‐ester‐imide)s have been synthesized by solution polycondensation of certain dianhydrides containing performed ester groups with aromatic diamines incorporating phenyl‐substituted quinoxaline units. The thermal stability as well as the dielectric properties of these compounds are discussed and compared with those of related heterocyclic polymers.
The synthesis and investigation of thermostable soluble polybenzazoles
Authors: Izyneev A. A. , Varga J. , Mazurevskaya Sh. P. , Novak I. S. , Mazurevsky V. P. , Mognonov D. M. , Radnaeva L. D.
Published: April 2003

The poly(benzimidazole)s and poly(amidobenzimidazole)s produced on the base of different tetramines, diphenylate of dicarboxylic acids, and ε‐caprolactam or diamines are investigated. In the synthesis were used 3,3′‐diaminobenzidine or aromatic tetramines containing methylene, oxygen, or sulfon groups between the benzene cycles. The produced polymers are thermostable, soluble, and have high enough molecular weights.
Synthesis of new N,N′‐bisimides for thermostable polymers
Authors: Mognonov D. M. , Radnaeva L. D. , Varga J. , Tsyrennimaev V. Z. , Erzh B. V. , Izyneev A. A. , Golovach G. I.
Published: April 2003

New N,N′‐bisimides were synthesized by condensation of polynuclear aromatic diamines with maleic anhydride. The obtained N,N′‐bisimides are crystalline yellow‐coloured compounds, soluble in acetone, dioxan, amidic solvents, organic and inorganic acids. Their structure was identified by elemental analysis, NMR and IR spectroscopy. The N,N′‐bisimides were polycondensated with diamines in cresol solution to high polymers.
SAXS study of polyamide 6 swollen in methanol
Authors: Baldrian J. , Pleštil J.
Published: April 2003

The effect of the annealing temperature on the structure of unoriented polyamide 6 was studied by swelling in methanol and small‐angle X‐ray scattering. The observed values of mean‐square fluctuations of scattering density can be explained by using a model with an inhomogeneously swelling amorphous phase. An increase in the annealing temperature improves the internal structure of the lamellae and reduces coarseness of their surface. The concentration of polymer chains in the centre of the swollen amorphous interlayer strongly decreases.
Charakterisierung diolmodifizierter Epoxidnetzwerke mittels viskoelastischer Messungen
Authors: Wolff D. , Havránek A. , Schlothauer K. , Fedtke M.
Published: April 2003

Die viskoelastischen Eigenschaften von diolmodifizierten Epoxidnetzwerken auf der Basis von Bisphenol‐A‐Diglyeidether wurden in Abhängigkeit von der Probenzusammensetzung für zwei verschiedene Beschleuniger, Magnesiumperchlorat und N,N‐Dimethylbenzylamin, untersucht und im Zusammenhang zur Netzwerkstruktur diskutiert.
Discrete strength spectrum of natural silk fibres
Authors: Tsoj B. , Karimov C. N. , Lukashov A. V. , Feofanov V. V.
Published: April 2003

With filaments of natural silk a discrete spectrum of tlie levels of strength was observed. These levels correspond to nine discrete length values of microtlefects, calculatecl by tlic formulas of failure mechanics. There is a clear correlation with the data of x‐ray measurements. The levels of strength are not affcctctl by temperaturc antl scale factor. From the results it coulcl be conclutled that tlie effect of sample size and of external actions on the filanieut consists in the redistributinii of the strength levels.
Synthesis of polyetherols with s‐triazine ring catalyzed by tetrabutylammonium hydroxide
Authors: Kucharski M. , Lubczak J.
Published: April 2003

Some results of invesgitations of the synthesis of polytherols with s‐triazine ring by reaction of melamine with oxiranes using tetrabutylammonium hydroxide as catalyst are presented. The physico‐chemical properties of the products have been examined. By means of analytical methods, infrared and 1H‐NMR spectroscopy the structure of the compounds has been determined.
Permanganate/malonic acid initiated polymerization of acrylamide and methacrylamide
Authors: Behari K. , Gupta K. C. , Raja G. D. , Das P.
Published: April 2003

The kinetics of aqueous polymerization of acrylamide and methacrylamide using the redox pair potassium permanganate and malonic acid was studied. It was found that the order of the polymerization reaction is 0.5 with respect to permanganate and malonic acid, respectively, and 1.0 with respect to the concentration of the monomers. Polymer samples were prepared under different conditions, and their viscosity average molecular weights were determined. A plausible mechanism for the explanation of the experimental results is proposed.
Zu einigen Besonderheiten der Struktur von Kompositen aus Polyethylen und Polystyren
Authors: Bogdanov B. , Mihailov M. , Ilieva I.
Published: April 2003

Die bei der Kristallisation von Mischungen aus Polyethylen und ataktischem Polystyren entstchenden Strukturen wurden im Lichtmikroskop untersucht. Charakteristische Unterschiede wurden gefunden, wenn die Polystyrenkomponente auf das Polyethylen aufgepfropft ist.
Further studies on the stability of polystyrene suspensions
Authors: Carrique F. , Salcedo J. , Cabrerizo M. A. , González‐Caballero F. , Delgado A. V.
Published: April 2003

A device and method have been developed for the precise determination of the time evolution of the stability of suspensions. The technique is applied to the study of suspensions of well characterized spheres of polystyrene. The change with time of the light absorption properties of the studied systems were detected by computer control of the spectrophotometer employed. The experimental results, shown as stability of the suspensions as a function of KCl, CaCl2 and La(NO3)3 concentrations, are discussed in the light of the theoretically calculated curves of interaction energy between polystyrene spheres from DLVO theory. A very good agreement as represented by critical coagulation concentration is found between theory and experiment for the three electrolytes employed.
Concentration dependence of the sedimentation coefficient of poly(amidobenzimidazole)
Authors: Tarabukina E. B. , Slavina Z. N. , Frenkel S. Ya.
Published: April 2003

The concentration dependence of the sedimentation coefficient of poly(amidobenzimidazole) solutions in the neutralized form in DMAA and in the hydrochloride form in DMAA +0.3% LiCl has been investigated. With the aid of this dependence, the molecular weights Mks and the coefficients (1‐b) in the equation S0 = K = M1–b for these two systems were determined. The values of Mks obtained here agree with those obtained from sedimentation‐viscometric and sedimentation‐diffusion measurements. The macromolecules in both systems show different rigidities.
Poly(N‐vinyl pyrrolidone) as a template for the radical polymerization of 4‐vinyl pyridine
Authors: Awasthi Sanjay K. , Srivastava A. K.
Published: April 2003

The coefficient of interaction between poly(N‐vinyl pyrrolidone) and poly(4‐vinyl pyridine) is determined in solutions of the mixture of these two polymers in different solvents. The results show the complexation of the polymers. Maximum complexation occurred at molar ratio 1:1. The kinetics and mechanism of polymerization of 4‐vinyl pyridine in dimethylformamide with poly(N‐vinyl pyrrolidone) as a template is investigated.
Novolak phenol‐aldehyde oligomers as components for photoresists. Synthesis and modification
Authors: Dimitrov V. , Miloshev S. , Novakov P.
Published: April 2003

The paper presents a review of articles dealing with the synthesis and modification of novolak phenol‐aldehyde oligomers as components for the production of photoresists published in the period from 1976 till 1988. The catalysts and the reaction conditions of the synthesis of movolak oligomers using different phenols are discussed. The relationship between the initial components, reaction conditions and molecular weight characteristics of the obtained novolak oligomers is described. The modification of the novolak oligomers in order to improve their behaviour during alkaline development and etching is considered.
Influence of annealing on the dielectric properties of poly(vinylidene fluoride(0.98)‐co‐tetrafluoroethylene (0.02))
Authors: Wolak J. , Kulek J.
Published: April 2003

Measurements of dielectric properties and thermally stimulated discharge current were carried out for poly(vinylidene fluoride(0.98)‐co‐tetrafluoroethylene(0.02)) modified by polarization and annealing at high temperature. After polarization the polar β‐phase of PVDF appears. Annealing influences dielectric absorption connected with β‐α phase transformation. The increase of temperature sensitivity, monitored by dielectric measurements, in connection with decrease of tan δ forecasts the improvement of pyro‐ and piezoelectric properties.
Über die strahlenchemische Vernetzung von Halogenphenolnovolaken und Halogenphenolnovolak‐Bisazidgemischen
Authors: von Lampe I. , Wäsche M. , Lippitz A. , Lorkowski H.‐J.
Published: April 2003

XPS‐Untersuchungen und die Bestimmung der Elektronenstrahlempfindlichkeit an Halogenphenolnovolak‐Resistschichten ergaben, daß ein Vernetzungsmechanismus über Halogeneliminierung abläuft. Durch Bisazidzusatz wird der Vernetzungseffekt erhöht. Die strahlenchemisch induzierte Halogeneliminierung der untersuchten 4‐Halogenphenolnovolake steigt in der Reihenfolge Fluor‐Chlor‐Brom‐Iod.
Infrared study of polyethylene membranes during the gas diffusion process
Authors: Bratu I. , Mercea P.‐V.
Published: April 2003

The structural modifications of a polyethylene membrane caused by simultaneous action of strain deformation and the diffusion of argon or argon plus dioxan vapours through the membrane were studied with polarized IR light. For the interpretation of the results it was assumed that the absorption of the radiation depends on the orientation of the macromolecular chains of the sample and on the nature of the gases which diffuse through the membrane.
Ionotropic gels of alginate polyelectrolyte. I. Potentiometric determination of the ionization constant of alginic acid polyelectrolyte in relation to sol‐gel transformation mechanism
Authors: Hassan Refat M. , Abd‐Alla Mohamed A.
Published: April 2003

The ionization constant of alginic acid as anion polyelectrolyte has been determined potentiometrically at a constant ionic strength of 1.0 mol dm−3. The experimental observations showed that alginic acid takes up 5.4 mequ. Na+/g at pH = 3.3 and the pK is 2.93 at 25°C. The mechanism of sol‐gel transformation in relation to the ionization constant is discussed.
Physical and chemical properties of acrylamide polymers and copolymers. Review
Authors: Myagchenkov V. A. , Kurenkov V. F.
Published: April 2003

The physical and chemical properties of acrylamide polymers and copolymers in aqueous, aqueous‐salt, and aqueous‐organic media are analysed. The main emphasis is given to the assessment of the effect of the medium quality on the conformation state of the macromolecules in the solution. Particular attention is directed to acrylamide polymers and copolymers with ionogenic groups, as these exhibit most interesting features of synthesis and a complex of solution properties.
The processing and structure of composites of isotactic polypropylene and atactic polystyrene with a high dispersion of the polystyrene component
Authors: Pluta M. , Milczarek P. , Włochowicz A. , Kryszewski M.
Published: April 2003

Heterogenic polymeric systems of polypropylene and polystyrene with different morphology have been obtained by UV initiated polymerization of liquid styrene within polypropylene matrices of controlled molecular and supermolecular structure. The influence of styrene treatment and its polymerization in situ on the crystalline structure of the polypropylene matrix is determined, and the correlation between the initial structure of the matrix and the dispersion of the polystyrene component is shown.
Aromatic diamines as multifunctional ingredients in halogenated butyl rubber
Authors: Ivan G. , Tavaru E. , Giurginca M.
Published: April 2003

The crosslinking of halogenated butyl rubber by aromatic diamines is investigated. The crosslinking process was realized by thermal activation or in conditions of mechanical processing. The main investigated influencing factors were nature of the diamine, temperature, nature of halogen, presence of metallic oxides. The formation of bound antioxidant was made obvious by the determination of the extractable amount of antioxidant as well as by following the ageing behaviour of the elastomer.
Copolymerization of multimethacrylate with vinyl monomers
Authors: Jantas R.
Published: April 2003

The free radical copolymerization of multimethacrylate with styrene and acrylonitrile in dilute dimethylformamide solutions has been investigated. The effects of the copolymerization conditions on the content of unreacted double bonds, molecular weight, and composition of the copolymers were determined. Based on IR and 1H‐NMR spectra the structures of the copolymers were confirmed. The examination of copolymerization in the presence of AIBN labeled with 14C allowed to determine the number of branching points in a macromolecule. The results show that the copolymerization process results in copolymers composed partly of ladder‐type blocks and blocks of vinyl monomer units. The thermal properties of the copolymers were determined.
Characterization of diol modified epoxy resins by means of thermomechanical analysis and measurements of compressive modulus
Authors: Tänzer W. , Häusler K.‐G. , Kunze A.
Published: April 2003

Glass transition temperatures Tg of diol modified epoxy resin networks were determined using thermomechanical analysis. These temperatures depend on concentration and chain length of the diol and furthermore on the type of the accelerator. Measurements of uniaxial compressive modulus gave a similar dependence for the shear modulus G and the network density.
A critical analysis on different criteria of the mechanical stability of polymeric membranes operating in the pressure‐driven processes
Authors: Islam M. A. , Dimov A.
Published: April 2003

Different criteria for the evaluation of the mechanical stability of polymeric membranes have been discussed. It has been illustrated that the hysteresis curves are the measure only for the plastic deformation of the membrane in a given cycle. Flux‐decline rate accounts for the viscoelastic and plastic deformation of the membrane. For the appropriate characterization of the mechanical stability all types of deformation should be taken into account. In the present paper a criterion is proposed which accounts for the elastic, viscoelastic, as well as plastic deformations of the membrane.
Optical absorption in gamma irradiated poly(vinyl alcohol)‐CoCl2 composites
Authors: Sharaf F. , Khaled M. A. , Abdel‐Rahman A. A. , Basha A. F.
Published: April 2003

Optical absorption measurements were performed on cast thin films of poly(vinyl alcohol) and its composites with cobalt chloride before and after gamma irradiation. Identification of the structure and assignments of energy bands have been derived in terms of ligand field theory. A mechanism based on the equilibrium between six‐coordinated and four‐coordinated symmetry is proposed to account for the obtained spectra. The symmetry is found to be altered with both cobalt concentration and gamma irradiation dose.
Bildungsweise, Strukture und Anwendungsmöglichkeiten von Komplexen zwischen Polyelektrolyten und ionischen Farbstoffen (Literaturübersicht) Teil II: Komplexe zwischen anionischen Polymeren und kationischen Farbstoffen
Authors: Dawydoff W. , Linow K.‐J. , Philipp B.
Published: April 2003

Bildungsweise und Struktur von Komplexen zwischen anionischen Polymeren und kationischen Farbstoffen werden beschrieben, wobei sowohl synthetische Polyelektrolyte als auch saure Polysaccharide und Peptide betrachtet werden und als Farbstoffkomponente Acridinorange und Methylenblau im Mittelpunkt stehen. Auf einige praktische Anwendungsmöglichkeiten von Polyelektrolyt‐Farbstoff‐Komplexen sowie auf die Bindungsarten zwischen den Komplexbestandteilen wird eingegangen.
The copolymerization reactions of N‐(2‐methyl‐5‐dimethylaminophenyl)maleimide
Authors: Lokaj J. , Bílá J.
Published: April 2003

The radical copolymerization of N‐(2‐methyl‐5‐dimethylaminophenyl)maleimide (I) with styrene (S), methyl methacrylate (MMA), 2‐dimethylaminoethyl methacrylate (DAMA), acrylonitrile (AN), methacrylic acid (MA), and isoprene (IP) was investigated. The reactivity ratios of pairs of monomers I ‐ S, I ‐ MMA were determined, and the Alfrey‐Price constants e, Q of the imide I were calculated. Along with the copolymerization of I with IP, the Diels‐Alder addition proceeding in parallel was also followed.
Biodegradable polymers. 6th comm. Polymerization of ϵ‐caprolactone
Authors: Rafler G. , Dahlmann J.
Published: April 2003

The ring‐opening polymerization of ϵ‐caprolactone was investigated in dependence on the most important reaction parameters. It was found that the monomer conversion is above all determined by polymerization temperature just as type and concentration of initiator. High yields of polymer can be obtained by initiation with tin(II) carboxylates, tin(II, IV) halogenides and titanium alkylates. The molecular weight of the polymer depends in a complex manner on the reaction conditions because the primary ring‐opening reaction is accompanied by consecutive reactions. The values of molecular weight pass through a maximum.
Topologische Struktur und Lösungseigenschaften von verzweigten diallylesterpolymeren
Authors: Pavlova O. V. , Kireeva S. M. , Sivergin Ju. M.
Published: April 2003

Die topologische Struktur und die Eigenschaften verdünnter Lösungen von verzweigten Polymeren auf Basis von Diallylestern der Sebazin‐und Isophthalsäure wurden in einem weiten Bereich der Molekülmassen untersucht. Die untersuchten Systeme stellen stark verzweigte Polymere dar, die kammartige und statistische Kurzkettenverzweigungen sowie eine große Anzahl intramolekularer Cyclen enthalten. In verdünnter Benzenlösung haben die verzweigten Polymere eine untere kritische Mischungstemperatur. In einem guten Lösungsmittel weisen die polymeren Knäuel sehr niedrige Werte der Grenzviskosität auf. Diese Erscheinungen hängen mit der besonderen topologischen Struktur der untersuchten Systeme zusammen.
Löslichkeitsuntersuchungen an Copolymeren aus Styren und Maleinsäureanhydrid durch Trübungstitration
Authors: Francuskiewicz F. , Heinemann M. , Müller S. , Glöckner G.
Published: April 2003

Mittels Trübungstitrationen an Lösungen von Styren/Maleinsäureanhydrid‐Copolymeren wurde festgestellt, daß mit Alkoholen als Fällungsmittel bevorzugt nach der Molmasse fraktioniert werden kann, während sich Kohlenwasserstoffe besser zur Trennung nach der chemischen Zusammensetzung eignen. Methanolyse‐Reaktionen an den Anhydridbausteinen verändern die Fällbarkeit merklich.