bluuebunny/crossref_metadata_2025 huggingface dataset:
Der Einfluß von Kristallviolett auf die Strukturbildung von Poly(vinylidenfluorid)
Authors: Schmolke R. , Elling B. , Künstler W. , Danz R. , Geiss D.
Published: April 2003

Der Einfluß von Kristallviolett auf die Strukturbildung von PVDF‐Filmen aus DMSO‐Lösungen wird mittels IR‐Spektroskopie untersucht. In Abhängigkeit von der Kristallviolett‐Konzentration entstehen Filme mit bevorzugter α‐, γ‐ oder β‐Modifikation. Bei einem hohen Anteil des Additivs werden unorientierte PVDF‐Filme mit reiner β‐Struktur erhalten
Bildung strukturierter Polyethylen‐Schichten auf hochgeordneten Polyethylen‐Fäden
Authors: Schulz E. , Hirte R.
Published: April 2003

Es wird über Untersuchungen zur Herstellung von Polyethylen‐Schichten auf hochfesten PE‐Fäden berichtet. Der Einfluß der Unterlage und der Wachstumsbedingungen auf die Ausbildung der Struktur und die Kinetik der Aufwachsprozesse wird diskutiert.
Thermodynamics of cationic polymerization. 1. Cationic propagation
Authors: Hallpap P. , Bölke M. , Hartung H. , Stadermann D. , Heublein G.
Published: April 2003

Latterly, the formation enthalpies were determined for many carbocations by means of thermochemical methods. Therefore a thermodynamical view is possible for the propagation reactions of the cationic polymerization to a larger extent.
Concentration of active centres in the Ziegler‐Natta polymerization of styrene
Authors: Gehrke K. , Runge H. , Buhrow J. , Schröder S.
Published: April 2003

The kinetics of styrene polymerization with the nickel naphthenate/BF3·Et2O/AlEt3 catalyst system is studied. The concentration of active centres is calculated by various methods from the number average of the degree of polymerization and the amount of polymer.
Photoinitiierte Vernetzung eines polymeren Epoxides durch Oniumsalze
Authors: Franzke M. , Lorkowski H.‐J. , Timpe H.‐J. , Wigant L.
Published: April 2003

Durch Copolymerisation von Cyclohexylmethacrylat und Glycidylmethacrylat gewonnene polymere Epoxide bilden in Verbindung mit einigen Diaryliodonium‐ und Triarylsulfoniumsalzen auf Cr‐beschichteten Glassubstraten homogene transparente Schichten. Während der Bestrahlung mit Licht der Wellenlänge λ = 250 bis 300 nm wird das Polymer durch die kationischen Photolyseprodukte der Oniumsalze vernetzt. Die Sulfoniumsalze sind dabei effektiver als die Iodoniumsalze. Für eine optimale Vernetzung ist ein wenig nucleophiles Anion, wie z. B. Hexafluorophosphat, notwendig. Die Bildung des Katalysators kann durch Anthracen, 9.10‐Phenanthrenchinon, Benzophenon und Benzoinisopropylether sensibilisiert werden, womit der Empfindlichkeitsbereich der Lacksysteme auf 360 bis 420 nm ausdehnbar ist. Die Empfindlichkeit der Systeme ist vergleichbar mit denen anderer, bereits verwendeter Photopolymer systeme.
Bestimmung des Chlorgehaltes in Polymeren mittels der β‐Rückstreumethode
Authors: Brunner G. , Hösselbarth B. , Tannert F.
Published: April 2003

Es wurde gefunden. daß sich die Zählrate der β‐Rückstreuung für eine gegebene Zählanordnung nahezu linear zum Chlorgehalt in nachchloriertem PVC und chloriertem PE (Bereich: 35 bis 73% Chlor) verhält. Als Chlorbestimmungs methode in Polymeren gilt die β‐Rückstreumethode als zuverlässig und leicht handhabbar. Der mittlere Fehler des Mittelwertes ist ≦±0.2% Chlor.
Thermal transitions in solution cast poly(vinyl chloride)/poly(methacrylate) blends
Authors: Bittrich H.‐J. , Schlothauer K. , Steinau U.‐J. , Tanneberger H.
Published: April 2003

Phase behaviour of poly(vinyl chloride)/poly(methyl methacrylate) and poly(vinyl chloride)/poly(butyl methacrylate) blends prepared from solution was investigated using differential scanning calorimetry. Indications for compatibility were found only at small concentrations of the second component. Stereospecific association seems to be very important for such systems. Glass transition and melting behaviour is also influenced by the preparation method.
Studies on imidazolium‐p‐chlorophenacylide initiated copolymerization of methyl acrylate with styrene
Authors: Nigam S. K. , Srivastava A. K.
Published: April 2003

The radical copolymerization of methyl acrylate and styrene initiated by imidazolium‐p‐chlorophenacylide has been studied. The reaction orders with respect to initiator and monomer concentrations, and the energy of activation were determined. By NMR spectroscopy is shown that alternating copolymers resulted.
Copolymers. IX. Structural modifications in synthesis and spinning of some acrylic copolymers
Authors: Nicu M. , Nicu V. , Ricinschi C. , Asandei N.
Published: April 2003

By means of IR spectroscopy the structural modifications appearing during the synthesis, drying and spinning of some acrylonitrile copolymers containing vinyl acetate, α‐methyl‐styrene, cinnamic acid, acrylates, and monofumarates have been studied. The results are discussed.
Untersuchungen zur nickelkatalysierten Ziegler‐Natta‐Homopolymerisation des Butadiens in Benzen
Authors: Gebauer U. , Ludwig J. , Gehrke K.
Published: April 2003

Die mit dem komplexkoordinativen Katalysatorsystem Nickeloctoat/Bortrifluoridetherat/Aluminiumtriethyl ausgelöste Butadienpolymerisation im Lösungsmittel Benzen wurde hinsichtlich des Einflusses von Monomerkonzentration und Polymerisationszeit untersucht. Es sollte somit die Möglichkeit erarbeitet werden, die hierbei erhaltenen Ergebnisse mit denen in anderen Lösungsmittelsystemen zu vergleichen.
Influence of organic compounds on the cyclization, degradation and carbonization processes of poly(pyromellitimides)
Authors: Sazanov Yu. N. , Stepanov N. G. , Shibaev L. A. , Tsapovetsky M. I. , Antonova T. A. , Gribanov A. V. , Szekely T. , Bertoti I. , Toth A. , Blazso M. , Jakab E.
Published: April 2003

The methods of mass‐spectrometric thermal analysis, IR spectroscopy, pyrolysis gas chromatography and X‐ray photoelectron spectroscopy were used for the investigation of the effect of benzimidazole (BI) on the thermal behaviour of poly(4,4′‐oxydiphenylene)‐pyromellitamic acid (PAA). It is shown that the formation of a complex of PAA with BI is accompanied by the ordering of amide groups of the polymer, which leads to a decrease in the number of defective units in the resulting polyimide.
Infrared spectroscopy of polymeric core‐shell latexes
Authors: Lange J. , Hergeth W.‐D. , Wartewig S.
Published: April 2003

Infrared spectra of films of poly(vinyl acetate)/poly(styrene) core‐shell polymers were measured. Some vibrationa bands are sensitive to polymer composition. On the basis of this measurements it is possible to make some statements to the formation of the interfacial layer and to deduce its thickness. The results are in good agreement with values resulting from other methods.
Industrial recovery of poly(methyl methacrylate) topcoat
Authors: Enyiegbulam M. E.
Published: April 2003

Methyl methacrylate monomer of very high grade was recovered from an industrial dump of hard solid poly(methyl methacrylate). The recovered monomer was bulk polymerized to obtain a liquid polymer. The liquid poly(methyl methacrylate) was found adequate for reinjection into the industry as a topcoat in synthetic marble production.
Morphological aspects in photooxidation of isotactic polypropylene
Authors: Mucha M.
Published: April 2003

The photooxidation of isotactic polypropylene films with different morphological structure and various thicknesses was studied. The progress of photodestruction was followed by measurements of the intrinsic viscosity and by infrared spectroscopy. The results reveal a clear effect of the thermal history of the polymer on the photooxidation process. Thermal preoxidation during melt processing or crystallization at high temperatures in air cause the formation of hydroperoxides which accelerate the photooxidation process. No essential influence of the morphological structure on the photooxidation process was observed.
Crystallinity of poly(tetrafluoroethylene)
Authors: Ścigała R. , Wlochowicz A.
Published: April 2003

A procedure for the estimation of the crystallinity of poly(tetrafluoroethylene) is proposed. For this purpose the X‐ray intensity distribution curve has been described by the Pearson VII function. The solution is presented in full and simplified forms. The theoretical approach is confirmed by experimental data.
Besonderheiten der Strukturbildung bei der Koagulation von Polymermischungslösungen. 1. Mitt.: Voraussetzungen und Mechanismus des Entstehens hochporöser Strukturen
Authors: Albrecht W. , Makschin W. , Klug P. , Weigel Th. , Gröbe V.
Published: April 2003

Bei der Koagulation von Polymermischungslösungen entstehen bei einer Vielzahl von Polymerpaaren bemerkenswert hohlraumreiche Fällungsstrukturen, deren Porensystem gegenüber einer Trocknung weitgehend beständig ist. Ausgehend von diesem Befund wurden Ursachen ermittelt, unter denen diese erhöhte Porosität realisiert wird. Sie tritt auf, wenn gleichzeitig sowohl die Polymermischungen im gelösten Zustand zwei Phasen bilden als auch eine hohe Koagulationsgeschwindigkeit des Hauptpolymers vorhanden ist. Ein Porenbildungsmechanismus wird vorgeschlagen, der auf dem Vorhandensein von zwei Verfestigungsfronten beruht.
Polymer complexes. V. Thermal stability of poly(acrylamido‐4‐aminoantipyrinyl) homopolymer and polymer complexes of acrylamido‐4‐aminoantipyrinyl with some transition metal salts
Authors: El‐Sonbati A. Z. , El‐Dissouky A. , Diab M. A.
Published: April 2003

Poly(acrylamido‐4‐aminoantipyrinyl) homopolymer and polymer complexes of acrylamido‐4‐aminoantipyrinyl with some transition metal bromides and uranyl acetate have been prepared. The materials were characterized by elemental analysis, UV‐vis and infrared spectroscopy, and measurement of the magnetic moment. The thermal stabilities of the homopolymer and of the polymer complexes were studied by means of thermogravimetry. The activation energies of the degradation of the samples were calculated.
Strukturcharakterisierung von Polymeren mit physikalischen Methoden
Authors: Fink H.‐P. , Geiss D. , Walenta E. , Purz H. J. , Schmolke R. , Frigge K.
Published: April 2003

Die kombinierte Anwendung der IR‐ und NMR‐Spektroskopie, der Röntgenklein‐ und ‐weitwinkelstreuung und elektronenmikroskopischer Methoden wird an ausgewählten Beispielen von Polymerfestkörpern demonstriert. Neuere Ergebnisse zu PE‐Strukturen einschließlich hochfester/hochmoduliger Fasern, zur strukturellen Erklärung von PVDF‐Polarisationseffekten sowie zu Strukturveränderungen der Cellulose infolge Natronlaugebehandlungen werden vorgestellt. Die Schlüsselrolle der IR‐Spektroskopie für die Analyse chemischer Strukturen wird an Beispielen aufgezeigt.
Untersuchungen an Spiroorthoester‐Copolymeren
Authors: Haase L. , Klemm E.
Published: April 2003

Monofunktionelle Spiroorthoester werden in Gegenwart eines Bisspiroorthoesters oder Bisepoxides mit Et3O+SbCl6‐als Initiator thermisch copolymerisiert. Aus den Dichten der Monomermischungen und der entstandenen Polymerkörper wird die Gesamtvolumenschrumpfung der Polymerisation berechnet. Die resultierenden Copolymere werden hinsichtlich extrahierbarer Anteile, Glastemperatur und thermischem Abbau untersucht. Durch Variation der Zusammensetzung der Monomermischungen entstehen Copolymere mit unterschiedlichen mechanischen Eigenschaften, die als Bestandteil neuartiger Werkstoffe geeignet sind.
Kinetics of the condensation reaction of carboxylated polymers activated by dicyclohexylcarbodiimide
Authors: Dumitriu M. , Dumitriu S. , Popa M. I. , Dumitriu C.
Published: April 2003

Kinetical studies were performed on the condensation reactions of 2‐aminopropane and two carboxylated polymers (poly(acrylic acid) and xanthan) in the presence of dicyclohexylcarbodiimide as an activator. The rate constants of the second order reactions were determined and discussed.
Amino resin microcapsules. I. Literature and patent review
Authors: Dietrich K. , Herma H. , Nastke R. , Bonatz E. , Teige W.
Published: April 2003

Amino resins can be applied as well materials for the microencapsulation of drugs, agrochemicals, adhesives, and dyestuff systems for pressure‐sensitive copying paper. The microencapsulation is carried out with unmodified or modified, etherified or non‐etherified amino resins, in most cases with addition of water‐soluble polymers as protective colloids.
Association of polyoxyethylene‐polyoxypropylene block copolymers in aqueous solution
Authors: Bloss P. , Hergeth W.‐D. , Döring E. , Witkowski K. , Wartewig S.
Published: April 2003

The water‐solubility of triblock copolymers of poly(oxyethylene) and poly(oxypropylene) is caused by the binding of water to the oxygen of the OE units. Two water molecules are bound to one OE unit as can be derived from measurements of ultrasound velocity and density of the solutions. This binding is lost by increasing the temperature, and, therefore, the polymer precipitates from aqueous solution. The existence of polymeric associates can be detected by investigations of the viscosity as well as by static and dynamic light scattering.
Viscometric and diffusion investigations in the cellulose/cadoxen/water system
Authors: Okatova O. V. , Lavrenko P. N. , Cvetkov V. N. , Dautzenberg H. , Philipp B.
Published: April 2003

By means of viscometric and diffusion measurements with CMC samples of DS ≈ 1 and different molecular weight in cadoxen (conventional cellulose solvent)/water systems the minimum cadoxen concentration still securing a valid evaluation of the data was assessed. The influence of the procedure of preparation of the CMC solution was investigated. A limiting ratio of cadoxen: water of about 1:10 was found. The results are discussed on the basis of a change in ionic strength on addition of cadoxen to a CMC/water system resulting in diminishing of polyelectrolyte effects.
Besonderheiten der Strukturbildung bei der Koagulation von Polymermischungslösungen. 2. Mitt.: Einfluß der Konzentration, Art und Menge an Zusatzpolymeren auf die Porosität
Authors: Albrecht W. , Makschin W. , Weigel Th. , Klug P. , Gröbe V.
Published: April 2003

Bei der Koagulation von Polymermischungslösungen entstehen hochporöse Fällungsstrukturen. In dieser Arbeit werden neben dem mathematischen Formalismus zur Vorhersage des zu erwartenden Porenvolumens Ergebnisse zum Einfluß der Konzentration, Art und Menge an Zusatzpolymer mitgeteilt. Der Vergleich von berechneten und gemessenen Porenvolumina zeigt gute Übereinstimmung und bestätigt damit die Vorstellungen zum Porenbildungsmechanismus bei der Koagulation von Polymermischungslösungen.
Anwendung der kontinuierlichen Thermodynamik auf die Berechnung des Phasengleichgewichtes in athermischen Lösungen polydisperser steifkettiger Polymere
Authors: Wohlfarth Ch. , Rätzsch M. T.
Published: April 2003

Die kontinuierliche Thermodynamik wird auf die Berechung des isotrop‐nematischen Phasengleichgewichtes in Systemen aus einem Lösungsmittel und einem polydispersen Polymer angewandt. Die Makromoleküle werden als starre Stäbchen betrachtet und sind durch eine Schulz‐Flory‐Verteilung bezüglich ihrer Segmentzahl (Molmasse) charakterisiert. Am Beispiel des Flory‐Modells für die chemischen Potentiale starrer Stäbchen wird der Einfluß der Verteilungsfunktion und ihrer Momente auf das Phasenverhalten im athermischen Grenzfall diskutiert.
Chemical modification as a method of synthesis of organometallic polymers
Authors: Sergeev V. A. , Vdovina L. I.
Published: April 2003

Chemical modification as a prespective method for synthesizing organometallic polymers is discussed. High‐molecular compounds with benzene rings are used as macroligands to synthesize macromolecular transition metal π‐complexes.
Effects of thermal ageing on thermoluminescence of an epoxy resin composition
Authors: Subocz J.
Published: April 2003

Thermal ageing of Epidian‐2 epoxy resin results in quenching and decrease in energetic depth of dopant thermoluminescence (TL) centres. The existing correlation between the depths of TL centres and the contents of methylene and methyl groups suggests that these groups are the cause of the dopant TL peaks. The SiO2 filler exhibits catalytic effects and restricts the formation of methylene and methyl groups in the resin.
Cationic polymerization of isobutylene initiated by Friedel‐Crafts catalysts. Peculiarities of the initiation reaction in a non‐polar medium
Authors: Khalafov F. R. , Melnikova N. E. , Nasirov F. M. , Krentsel B. A.
Published: April 2003

The effect of water on the cationic polymerization of isobutylene by AlEtCl2 in n‐heptane has been studied. The condition of complete polymerization inhibition is attained at [H2O] ≦ 10−5mol/1. Slow polymerization with an induction period is detected at [H2O]/[AlEtCl2] ≦ 1. By means of 2,6‐DTBP and O2 two mechanisms of initiation proceeding at the same time have been found: a cocatalytic mechanism and direct catalysis by means of a single‐electron transfer from isobutylene to AlEtCl2. The possibility of the control of the reaction is shown.
Characterization and radiometric studies on poly(methyl methacrylate) doped with some amine derivatives
Authors: Sayyah S. M. , Sabbah I. A. , Said F. I.
Published: April 2003

Some p‐phenylene diamine condensation products with different organic acids were synthesized. The effect of γ‐irradiation on PMMA films doped with three samples of these amines was investigated by ultraviolet spectroscopy. A change in the intensity of absorption bands with increasing irradiation dose was recorded. The use of PMMA films doped with this type of amines as dosimeter is suggested.
13C‐NMR‐Untersuchungen an Phenol‐Formaldehyd‐Harzen. 5. Zur Charakterisierung von Reaktionsprodukten aus p‐Cumylphenol und Formaldehyd
Authors: Pasch H. , Goetzky P. , Hiller W.‐G.
Published: April 2003

Mit Hilfe empirischer Substituentenparameter wurden die 13C‐NMR‐Spektren des 2,6‐Bis(hydroxymethyl)‐4‐cumylphenols und des 2,6‐Bis(2‐hydroxy‐5‐cumylbenzyl)‐4‐cumylphenols (3) berechnet und interpretiert. Durch 13C‐NMR‐Spektroskopie wurde gezeigt, daß bei der Schotten‐Baumann‐Reaktion von 3 und 2‐Diazo‐1‐oxo‐1,2‐dihydronaphthalen‐5‐sulfochlorid die außenständigen Hydroxylgruppen von 3 bevorzugt reagieren.
Zur Verfolgung des Härtungsverhaltens von Epoxidharzen mit tertiären Aminen
Authors: Fedtke M. , Domaratius F. , Domaratius E. , Liška V.
Published: April 2003

Die Vernetzung von Diandiglycidether in Gegenwart tertiärer Amine wurde viskosimetrisch untersucht. Für die Beschreibung der Abhängigkeit der Viskosität von Zeit und Temperatur wird ein mathematisches Modell angegeben. Mit Hilfe dieses Modells lassen sich kritische Größen berechnen, die eine gute Beschreibung des Temperatur/Zeit‐Verhaltens der Harzmischung sowie einen Reaktivitätsvergleich ermöglichen.
The cationic polymerization of 2‐alkenyl furans. V. Kinetic of the polymerization of 2‐ethenyl furan
Authors: Martinez R. , Alvarez R. , Gandini A.
Published: April 2003

The kinetic studies of 2‐ethenyl furan polymerization in methylene dichloride catalyzed by trifluoroacetic acid, showed a pseudo second order behaviour with deviations to the first or third order in dependence on the concentration range of the initiator. The rate constant is directly proportional to the square of the initial concentration of initiator and inversely proportional to the initial concentration of monomer. During the polymerization the acid concentration decreases as a consequence of the formation of stable polymeric ions. Moreover, the alkylation of furan ring from the beginning of the polymerization is observed. A pseudo‐copolymerization mechanism is proposed to justify the experimental results.
Substitution effect in simple copolycondensation kinetics
Authors: Boryniec S.
Published: April 2003

Basing on dependences of formal kinetics for irreversible second order reactions, a kinetic equation of copolycondensation (interbipolycondensation) of bifunctional monomers has been derived for the case when the reactivity of functional groups of the intermonomer changes with the transition from monomer to dimer, while the reactivity of the functional groups of the other types of monomer does not change in the course of the process. Numerical solution of this equation makes it possible to show the action of the simultaneous occurence of the copolycondensation effect and of the substitution effect in an intermonomer.
Characterization of resins prepared by polycondensation of egyptian bagasse pith and bisphenol A. Part I. Physicochemical properties of the moulded shapes
Authors: Sayyah S. M. , Saad S. M. , Elwy E.
Published: April 2003

Optimum conditions have been established for the synthesis of linear, soluble, and easily mouldable condensation products from Egyptian bagasse pith using bisphenol A as the condensation agent. Thin layer chromatographic technique was used for characterizing the products. The obtained condensate resins were treated with phenol formaldehyde, anthracene formaldehyde, and naphthalene formaldehyde to get different types of moulded products, which were found to be mechanically harder and chemically more stable than those of a phenol formaldehyde resin of novolac type.
History, present state and future of high speed spinning
Authors: Beyreuther R. , Schauer G. , Schoene A.
Published: April 2003

The article gives a review of the development of high‐speed spinning, its to‐day position, and its scientific foundation. One of the problems of these spinning processes is the orientation of the yarns during spinning, which shall either be increased for getting fully drawn yarns or lowered for a higher productivity. Another problem is the mathematical modelling of the process as a supposition for further improvements. Therefore a modelling conception with derived knowledge is exhibited. For spinning speeds higher than 6000 m/min limitations concerning fibre structure formation, winding, reaching of necessary yarn properties, and economy come into sight. Nevertheless it is estimated that in the years after 2000 the top industrial spinning speeds will be 8000 to 9000 m/min.
Lichtinitiierte Polymer‐ und Polymerisationsreaktionen. 36. Mitt.: Photovernetzung vinlygruppenhaltiger Poly(dimethylsiloxane)
Authors: Müller U. , Timpe H.‐J. , Häusler K.‐G. , Peters K. , Wagner R.
Published: April 2003

Lineare vinylgruppenhaltige Poly(dimethylsiloxane) können durch eine photoinitiierte Radikalbildung in vernetzte Proben überführt werden. In CHCI3‐Lösungen erreichen die Quantenausbeuten der Doppelbindungsabnahme (Φp) Werte von 0,9 bis 2,5 Sie hängen vom Initiatortyp ab und sinken bei Erhöhung der Siliconkonzentration. Für lösungsmittelfreie Systeme kann ein ΦP‐Wert von 0,01 extrapoliert werden. Unter solchen Bedingungen erfolgt die Netzwerkbildung besonders effektiv mit Benzoinderivaten. Mit steigendem Vinylgruppengehalt der Silicone erhöht sich die Netzwerkdichte. IR‐spektroskopische Untersuchungen mit Benzoinderivaten als Initiator und die Charakterisierung der entstandenen Netzwerke zeigen, daß die Netzwerkbildung fast ausschließlich über die Vinylgruppen abläuft.
Characterization of resins prepared by polycondensation of Egyption bagasse pith and bisphenol A. Part II. Elemental analysis and thin layer chromatography
Authors: Sayyah S. M. , Saad S. M. , Elwy E.
Published: April 2003

Different resins were prepared by polycondensation of bisphenol A with compounds which may be produced during the acid hydrolysis of bagasse pith, e.g., glucose, xylose, and furfural. Further bisphenol A was condensed with constituents of bagasse pith, namely, pure soda lignin, holocellulose and resistant cellulose. The optimum conditions for thin layer chromatographic separation of these polycondensates were determined.
Untersuchungen zur Auflöusung von Cellulose in binäuren aprotischen Systemen. 4. Mitt.: Synthese neuer Aminoxide und Löuslichkeit eines Textilzellstoffs in Aminoxiden bzw. in binären Systemen mit Aminoxid als einer Komponente
Authors: Berger W. , Kabreklian V. , Keck M.
Published: April 2003

Neue Aminoxide wurden zur Prüfung ihrer Lösewirkung gegenüber Cellulose synthetisiert und mit N‐Methylmorpholin‐N‐oxid (NMMNO·H2O) verglichen. Untersucht wurde die Auflösung der Cellulose in aprotischen, O‐basischen Lösungsmittelsystemen, insbesondere in binären Gemischen aus NMMNO·H2O mit einer meist aprotischen Zweitkomponente. Das Celluloseausgangsmaterial und dessen Struktur wurden variiert.
Homo‐ und copolymerisation von Butadien und Isopren mit Ni/Ti/Al‐und Ni/B/AL‐katalysatorsystemen. I. Isoprenhomopolymerisation
Authors: Gebauer U. , Oberdöurfer A. , Donner C. , Gehrke K.
Published: April 2003

Die Isoprenpolymerisation mit dem Ziegler‐Natta‐Katalysatorsystem Nickeloctoat/Titantetrachlorid/Aluminiumtriethyl wurde hinsichtlich des Einflusses der Katalysatorbildungsreaktion, der Monomer‐ und Gesamtinitiatorkonzentration sowie der Polymerisationszeit auf charakteristische Kenngrößen der Polymerisationsreaktion (Umsatz, Molmassenhöhe, Mikrostruktur) untersucht. Durch die Anwendung kinetischer Auswertemethoden wurden wichtige Reaktionsgrößen ermittelt und somit ein direkter Vergleich mit Der analogen Isoprenpolymerisation unter Einsatz eines Ni/B/Al‐Katalysatorsystems ermöglicht.
Some specific features of the Valeur, Jarry, Geny and Monnerie (VJGM) lattice model
Authors: Gotlib Yu. Ya. , Torchinsky I. A. , Shevelev V. A.
Published: April 2003

In the framework of the tetrahedral lattice model of the polymer chain, a precise solution was obtained for the correlation function G(t) describing the relationships of polarized luminescence (PL) and the nuclear Overhauser effect (NOE) in polymers. The relationships of PL and NOE were compared on the base of precise and approximate (VJGM model) solutions.
Thermokinetic analysis of polymorphous transformations in the crystallization and orientation of flexible‐chain polymers
Authors: Elyashevich G. K. , Poddubny V. I. , Bezprozvannykh A. V.
Published: April 2003

The crystallization of flexible‐chain polymers capable of forming different polymorphous modifications was considered by using the thermodynamic approach and taking into account kinetic factors. Taking as examples poly(caproamide) and poly(vinylidene fluoride), the changes in free energies in the generation of different crystalline forms were calculated and phase diagrams were plotted in the coordinates degree of coiling of macromolecules and temperature. it was thus possible to establish the thermokinetic conditions for the formation of equilibrium and metastable modifications and the transitions between them.
Solution polymerization of methyl methacrylate initiated by a redox system
Authors: Abd El‐Hakim A. A. , Badran A. S. , Ayoub M. M. H. , Younan A. F.
Published: April 2003

Methyl methacrylate has been polymerized at different temperatures in water/isopropanol mixtures using sodium persulfate and sodium metabisulfite as the redox initiator system. The dependence of the rate of polymerization on the concentrations of isopropanol, initiator, and monomer, and on the reaction temperature was studied. The activation energy of the polymerization in different solvent mixtures was estimated from the temperature dependence of polymerization rate.
Rheologische Aspekte der experimentellen und theoretischen Untersuchung von Verfestigungsprozessen. Teil IV. Zum Erstarrungsverhalten gelatinehaltiger Informationsaufzeichnungsmaterialien
Authors: Schnabel R. , Schulze V. , Reher E.‐O.
Published: April 2003

Ein neues Konzept zur Bestimmung und Beschreibung des Phasenüberganges gelatinehaltiger Lösungen wurde entwickelt und getestet. Im Kurzzeitbereich wird die Erstarrung mittels der kinetischen Gleichung der Viskositätsfunktion beschrieben. Zur gleichzeitigen Erfassung der viskosen und elastischen Eigenschaften werden dynamische Charakteristiken genutzt. Der Sol‐Gel‐Phasenübergang wird von der Seite des Solzustandes in den Erstarrungs‐ und Verfestigungsprozeß eingeteilt und eine Grenze der Fließfähigkeit als Maß für den Erstarrungspunkt angegeben. Erstarrungsisothermen im Kurzzeitbereich werden durch ein Modell von Avrami‐Typ gut beschrieben.
Thermal stability of poly(acryloyl chloride) homopolymer and copolymers of acryloyl chloride with methyl acrylate
Authors: Diab M. A.
Published: April 2003

The thermal stabilities of poly(acryloyl chloride) homopolymers and copolymers of acryloyl chloride with methyl acrylate covering the entire composition range were studied by thermogravimetric analysis. The copolymers are less stable than poly(methyl acrylate). The activation energies of the decomposition of the copolymers and the reactivity ratios of the copolymerization were calculated.
Plasmaätzen dünner Schichten organischer Polymere. Teil IV. Poly(vinylalkohol)
Authors: Eggert L. , Abraham W. , Von Löwis M.
Published: April 2003

Für das Ätzen von Poly(vinylalkohol) im Sauerstoffplasma wurden einige Besonderheiten festgestellt. Die Kinetik des Schichtabtrags läßt den Schluß zu, daß eine relativ dicke, aber wenig ätzresistente „K‐Schicht”︁ im Verlauf des Plasmaätzens gebildet wird. Sie besteht möglicherweise zum Teil aus vernetzten Makromolekülen, konjugierten Doppelbindungen innerhalb der Polymerkette durch Dehydratisierung bzw. aus graphitischem und anoxidiertem Kohlenstoff. Aus der Temperaturabhängigkeit der Ätzgeschwindigkeit folgt die Annahme von zwei konkurrierenden Reaktionen, deren eine zum Schichtabbau, die andere dagegen zu weiterer Polymervernetzung führt.
Investigation of the thermal oxidative stabilization of PAN filaments in carbon fibre processing
Authors: Walenta E. , Fink H.‐P.
Published: April 2003

The thermal oxidative stabilization of PAN fibres was investigated by small and wide angle X‐ray scattering and by measurements of the fibre density. It has been proved that stabilization starts in the less ordered regions and proceeds to higher ordered domains. Dimensions of these regions were estimated.
Hybridnetzwerke – Wege zur Synthese und Nachvernetzung von methacrylatterminierten Epoxid‐Amin‐Prepolymeren. Unvernetzte Epoxid‐Amin‐Additionspolymere 30
Authors: Klee J. , Hörhold H.‐H. , Schütz H.
Published: April 2003

Die Reaktion von aminoterminierten Epoxid‐Amin‐Prepolymeren mit (2,3‐Epoxypropyl)methacrylat führt zu Prepolymeren mit Methacrylatendgruppen, deren Struktur durch Mn(VPO)‐Werte, Elementaranalyse, IR‐,1H‐NMR‐ und 13C‐NMR‐Spektroskopie gesichert ist. Durch Bestrahlung mit UV‐Licht erfolgt die Bildung von Hybridnetzwerken, die mittels Tg‐Bestimmung und IR‐Spektroskopie charakterisiert werden. Ferner wurde die Volumenkontraktion während der Polymerisation ermittelt.
Orientation ability of thermotropic liquid crystalline comb‐like siloxane polymers as studied by NMR spectroscopy
Authors: Roth H. , Krücke B.
Published: April 2003

Nematically and smectically ordered samples of comb‐like siloxane polymers were studied by FT‐1H‐NMR method to get information about the macroscopic order parameter varying the chain‐end length of the mesogenic side group. The proton spectra (line shape, splitting) reflect directly the role of the spacer in the ordering process of the comb‐like polymers.
Monomers in polymer dispersions. Part II. Sorption rates of monomers in polymer dispersions
Authors: Hörnig K. , Hergeth W.‐D. , Häusler K.‐G. , Wartewig S.
Published: April 2003

The sorption rate of monomers from the aqueous phase into polymer particles is determined by ultrasonic velocity measurements as well as by isothermal evaporation analysis. This sorption rate is higher than the sorption rate of monomer during the steady state of emulsion polymerization. Hence, the reaction proceeds under equilibrium conditions with respect to the monomer distribution between polymer particles and monomer reservoirs.
Untersuchungen zur gleichzeitigen Homo‐ und Heterosymplexbildung mit synthetischen Polyampholyten vom Pendant‐Typ
Authors: Kötz J. , Philipp B. , Kudaibergenov S. , Bekturov E. A.
Published: April 2003

Die Polyanion‐Polykation‐Wechselwirkung (Symplexbildung) Wurde bei zwei ampholytischen Copolymeren aus Vinylethinylpiperidol und Acryläure bzw. des N‐methylierten Analogen und Methacrylsäure turbidimetrisch, konduktometrisch und potentiometrisch untersucht. Die Ergebnisse werden unter dem Aspekt einer konkurrierenden Homosymplexbildung zwischen den funktionellen Gruppen des Polyampholyten und Heterosymplexbildung zwischen einer Art der funktionellen Gruppen des Polyampholyten und einem entgegengesetzt geladenen Polyion diskutiert und mit früheren Resultaten bei anderen ampholytischen Copolymeren verglichen.
Investigation of the structure of poly(dodecalactam) obtained by anionic bulk polymerization
Authors: Mateva R. , Krastev V. , Ivanova M. , Nedkov E.
Published: April 2003

The morphology and structure of poly(dodecalactam) obtained by anionic bulk polymerization in the presence of different activators have been investigated. The structure of the polymer samples was characterized by means of infrared spectroscopy, wide angle X‐ray scattering, calorimetry, and polarizing light microscopy. It was established that at cooling of the polymer melts two crystalline modifications are formed. The effect of the polymerization conditions and of the molecular weight on the formation of the α‐ and γ‐modifications is discussed.
Untersuchungen zum thermischen Verhalten von phenolharzgebundenen Cellulosepapier‐Schichtpreßstoffen. 1. Thermoanalytische Untersuchungen an den Schichtpreßstoffen und an ihren Komponenten
Authors: Goetzky P. , Gnauck Regine
Published: April 2003

Der thermische Abbau von phenolharzgebundenen Cellulosepapier‐Schichtpreßstoffen wird mit den Methoden der dynamischen Thermoanalyse untersucht und in Beziehung zum thermischen Verhalten der Komponenten und zur Flexibilisierung des Harzes mit Holzöl und Tricresylphosphat gesetzt.
Relaxation properties of an epoxy polymer plastified with maleic anhydride
Authors: Shut N. I. , Bartenev G. M. , Lazorenko M. V. , Sichkar T. G.
Published: April 2003

The relaxation properties of the epoxy dian polymer ED‐16 plastified with maleic anhydride were studied in the wide range of temperature from −150°C to + 500°C. The experimentally found great number of relaxation transitions are connected with the complex structure of the polymer and with the existence of a large number of different forms of molecular motion. The observed relaxations are classified and their characteristic constants (activation energy and preexponential factor) are given. A nonsegmental mechanism of the process of glass transition in highly crosslinked polymers is suggested.
Untersuchungen zur Polymerisation von Vinylchlorid in Mikrosuspension. Teil 1
Authors: Schirge H. , Schlegel R.
Published: April 2003

Bei der technischen Durchführung der Mikrosuspensionspolymerisation des Vinylchlorids wird eine konstante Bruttopolymerisationsgeschwindigkeit während des ganzen Reaktionsverlaufes angestrebt. Dies wird durch Verwendung eines Redoxsystems aus Dilauroylperoxid/Dicetylperoxidicarbonat, Cupfersulfat und Ascorbinsäure als Initiator erreicht.
Microporous membrane filters on the basis of poly(tetrafluoroethylene)
Authors: Kostov G. , Christova N. , Charadjiev P.
Published: April 2003

Microporous membrane filters were processed on the basis of different types of poly(tetrafluoroethylene) characterized by various enthalpies of crystallization and molecular mass, respectively. CaCO3, NaCl, and NH4Cl were used as appropriate reactants in order to form porous structure. The influence of the polymer as well as the type and concentration of the reactants on the properties of the membrane filters is studied.
Kinetical study of the condensation reaction of 2‐furaldehyde and 2‐furfurylidene methyl ketone. Solvent influence
Authors: De Los Rios M. Diaz , Planes R. L. , Cruz B. H. , Luna N. L.
Published: April 2003

The influence of solvent nature upon the formation rate of 2‐difurfurylidene ketone with the use of water, methanol, ethanol, and propanol as catalyst solvent was studied. It was verified that the reaction proceeds slowly in aqueous medium due to the low solubility of the reactants and intermediates.
Elektronenmikroskopische Untersuchungen von Polyethylenen. VII. Strukturen von UHMWPE nach Dehnung und verschiedenen thermischen Vorbehandlungen
Authors: Michler G. H. , Morawietz K.
Published: April 2003

An Polyethylen mit ultrahoher Molekülmasse (M̄w = 1,6 · 106) wurden elektronenmikroskopische Untersuchungen nach mechanischer Belastung und verschiedenen thermischen Vorbehandlungen durchgeführt. Die Dehnung erfolgte bei Raumtemperatur an ungetempertem und getempertem Material sowie bei höheren Temperaturen. Die zwischen den einzelnen Temperaturbehandlungen bestehenden Unterschiede im Dehnverhalten werden auf der Grundlage der Veränderungen der Strukturen der Lamellen und der zwischenlamellaren, amorphen Gebiete diskutiert. Der Einfluß der amorphen Phase auf Änderungen der Lamellengröße und räumlichen Anordnung während des Dehnprozesses wird ausführlich untersucht. Aus der quantitativen Auswertung der Lamellenlänge. Lamellendicke und Blöckchengröße werden Rückschlüsse auf die mikromechanischen Prozesse während des Dehnvorgangs, wie Lamellenrotation oder interlamellares Gleiten, gezogen.
Untersuchungen an photopolymerisierten Dimethacrylaten
Authors: Mallon H.‐J. , Utschick H. , Unseld W.
Published: April 2003

Die photoinitiierte Polymerisation von Dimethacrylaten mit den Initiatorsystemen Campherchinon/Dimethyl‐p‐toluidin sowie Phenanthrenchinon/Dibenzoylperoxid führt zu Produkten, die noch relativ hohe Anteile nicht umgesetzter Doppelbindungen und Restmonomere enthalten. Der Restmonomergehalt beeinflußt die Eigenschaften der Polymere. Dieser Effekt und die möglichen thermischen Nachreaktionen werden mittels DSC und thermomechanischen Messungen nachgewiesen.
Ultrasonic mechanochemical degradation of the ternary copolymer poly(acrylonitrile‐co‐vinyl acetate‐co‐α‐methylstyrene)
Authors: Oprea C. Vasiliu , Popa M.
Published: April 2003

The ultrasonic mechanochemical degradation of poly(acrylonitrile‐co‐vinyl acetate‐co‐α‐methylstyrene) in solution is studied. Based on an experimental design whose results were processed on a computer, the function correlating the intensity of mechanodegradation with the reaction parameters concentration, temperature, and duration was obtained. The radicalic mechanism of the mechanochemical degradation was proved.
Synthesis and characterization of epoxy resin derived from cyanuric acid
Authors: Jain R. K. , Chandra S.
Published: April 2003

A procedure is described to synthesize heterocyclic cyanuric acid based triglycidyl isocyanurate resin in good yield and purity. The purity and configuration of the resin were confirmed by determination of the melting point, IR and NMR spectroscopy, elemental analysis, and epoxide equivalent.
Polymerization of acrylonitrile initiated with citric acid‐ceric ion redox system
Authors: Göçmen A. , Başcaran B.
Published: April 2003

The polymerization of acrylonitrile was studied in aqueous sulfuric acid medium with the redox initiator system citric acid‐ceric ion. The effect of ceric ion, citric acid and sulfuric acid concentrations and of temperature on the monomer conversion and average molecular weights of the polymer was investigated. A polymerization mechanism is suggested.
Study of electro‐optic properties of polymer dispersed liquid crystal films with low concentration of liquid crystal
Authors: Mucha M. , Kryszewski M.
Published: April 2003

Polymer dispersed liquid crystal films were prepared from radiation cured polyester resin containing low concentration of the nematic liquid crystal hexyloxycyanobiphenyl. The electro‐optic properties of the liquid crystal domains in the polymer matrix are dependent on the time elapsed between the occurrence of phase separation of the liquid crystal from the homogeneous mixture with the polymer precursor and the onset of polymer hardening.
Preparation and characterization of novel poly(phenylquinoxaline‐imide‐amide)s
Authors: Bruma M. , Hamciuc E. , Sava I. , Hamciuc C. , Belomoina N. M. , Krongauz E. S.
Published: April 2003

Poly(phenylquinoxaline‐imide‐amide)s have been prepared by low‐temperature solution polycondensation of aromatic diamines containing preformed phenylquinoxaline units and amide or imide groups with diacid chlorides of certain dicarboxylic acids incorporating imide rings. These polymers are easily soluble in polar aprotic solvents and give transparent films with high thermal stability and good electrical insulation properties.
Thermally stimulated depolarization currents in poly(vinyl alcohol) films
Authors: Rao V. V. R. Narasimha , Krishna K. Jeevana , Rao B. Subba
Published: April 2003

Poly(vinyl alcohol) films were polarized at different electrical field strengths and temperatures. The peak temperature of the TSDC spectra shifted to higher values with increasing polarizing field strength and polarizing temperature. The activation energies and relaxation parameters of the process were evaluated. Based on the results, the origin of TSDC was attributed to space charge polarization with some contribution of dipole orientation.
Infrared spectroscopic study of the functional composition of alkylaromatic nitrooligomer derivatives
Authors: Karaivanova M. , Kostov V. , Stoeva V.
Published: April 2003

By reaction of butadiene styrene rubber with a nitrating mixture alkylaromatic nitrooligomer derivatives are formed. The reaction was carried out in dichloroethane solution for 2 to 5 h at temperature 20 to 50°C. The functional composition of the nitrooligomers in dependence on temperature, reaction time, and composition of the nitrating mixture was determined by means of infrared spectroscopy. It was established that at high concentrations of NO2+ the nitration of the aromatic ring is predominant, while at low concentrations the nitration of the hydrocarbon chain prevails.
The dynamic behaviour of longitudinal and transverse components of the emitting oscillator and the internuclear vector manifested in polarized luminescence and in the nuclear overhauser effect
Authors: Gotlib Yu. Ya. , Torchinski I. A. , Shevelev V. A.
Published: April 2003

In the frame work of the tetrahedral lattice model with a three‐unit kinetic element, the time correlation functions were found. These functions describe the dynamics of “longitudinal” and “transverse” components of the emitting oscillator vector of the luminescent marker included in the side group or the dynamics of the internuclear vector of 13C‐1H. The expressions were obtained for the factor of luminescence depolarization (Y), the spin‐latice relaxation time (T1C) and for the nuclear Overhauser effect (NOE) of the 13C nuclei. The specific features of the behaviour of Y, T1C and NOE reflect the spectral characteristics of “longitudinal” and “transverse” relaxation processes.
The inhibited copolymerization of acrylonitrile with zinc acrylate in dimethylformamide solution
Authors: Czerniawski T. , Wojtczak Z.
Published: April 2003

The results of an investigation of the inhibited copolymerization of acrylonitrile with zinc acrylate in dimethylformamide are reported. Azobisisobutyronitrile and 2,2‐diphenyl‐1‐picrylhydrazyl were used as initiator and inhibitor, respectively. The obtained values of 2kdf = 1.60·10−5s−1 at 333 K and of the activation energy E = 127 kJ·mol−1 are within the limits of error to those obtained at the homopolymerization of acrylonitrile. This may be related to the large excess of acrylonitrile in the initial mixture with zinc acrylate.
Beitrag zur Anwendung der Methode Coazervativfraktionierung zur Herstellung von Fraktionen aus Polyethylen niederer Dichte im präparativen Maßstab
Authors: Braun D. , Rätzsch M. , Weber G. , Hofmann H. , Fiedler P. , Naumann O.
Published: April 2003

Gegenstand der vorliegenden Untersuchungen ist die Beschreibung und Anwendung der Coazervativfraktionierung zur Zerlegung von 500 bis 700g Polyethylen niederer Dichte. Die erhaltenen Fraktionen wurden durch Zahlen‐bzw. Gewichtsmittel der Molmasse, die Uneinheitlichkeit U und den Kontraktionsfaktor gß charakterisiert und können für Untersuchungen zur Struktur‐Eigenschafts‐Korrelation eingesetzt werden.
Investigation of poly(arylene vinylenes), 39. Synthesis of functionalized poly(1,4‐phenylene‐1,2‐diphenylvinylenes) by dehydrochlorination of unsymmetric p‐xylene dichlorides
Authors: Raabe D. , Hörhold H.‐H.
Published: April 2003

High molecular weight (Mn > 20000) phenylsubstituted poly(phenylene vinylenes) were prepared via the dehydrohalogenation route, starting from unsymmetrically substituted p‐xylene dichlorides. The detailed synthetic procedures are given for poly(1,4‐phenylene‐1,2‐diphenylvinylene) Tg = 250°C, poly[1,4‐phenylene‐1(4‐chlorophenyl)‐2‐phenylvinylene] Tg = 253°C, and poly[1,4‐phenylene‐1(4‐benzoylphenyl)‐2‐phenylvinylene] Tg = 223°C. All of these are thermostable polymers, which are soluble in common organic solvents and can be processed to amorphous thin films.
Hydrogels based on 2.2.3.3.4.4.4.‐heptafluorobutyl methacrylate
Authors: Koßmehl G. , Volkheimer J. , Schäfer H.
Published: April 2003

Hydrogels (crosslinked polymers with a defined content of water) from hydrophilic methacrylates and perfluorobutyl methacrylate were prepared by radical polymerization, followed by swelling in buffered isotonic sodium chloride solution. The obtained hydrogel samples have been characterized by their linear expansion to hydration, weight‐percent hydration, refractive index, extractables, percent transmission of visible light, and oxygen permeability. Such hydrogels are interesting as contact lens materials.
Aromatic poly(oxadiazole)s ‐ new aspects of their synthesis, structures and properties
Authors: Schulz B. , Leibnitz E.
Published: April 2003

Aromatic poly(oxadiazole)s are a class of heterocyclic polymers that show excellent thermal and chemical stability. Also, their electrical and optoelectrical properties are of interest. Here, a short review is given about recent results in the field of aromatic poly(oxadiazole)s elaborated in our research groups that emerged from the former Institute of Polymer Chemistry in Teltow‐Seehof. New aspects are described regarding the technology of poly(oxadiazole) synthesis via the oleum route. In detail the structures of poly(p‐phenylene‐1,3,4‐oxadiazole) in solution as well as in solid state are described. Moreover, the electrochemical behaviour and the dynamic‐mechanical properties are discussed.
STM investigations on primary particle morphology of polyaniline
Authors: Wessling B. , Hiesgen R. , Meissner D.
Published: April 2003

SEM investigation of polyaniline (PAni) layers showed that it is composed of around 10 nm small primary particles. This is in accordance with other earlier results.
Partial structure factor analysis of neutron reflectometry from spread monolayers of isotactic polymethyl methacrylate
Authors: Henderson J. A. , Richards R. W. , Penfold J. , Thomas R. K.
Published: April 2003

Neutron reflectivity data for isotactic polymethyl methacrylate monolayers spread at the air‐water interface have been analysed using the kinematic approximation. For surface concentrations up to 1.0 mg m−2 the data are well modelled by a uniform layer of thickness circa 20Å. Water may be uniformly dispersed throughout the film. However, to obtain agreement with the experimental reflectivities, a proportion of air must be included in the film which agrees with the findings of an earlier optical matrix type analysis. For surface concentration above 1 mg m−2, the uniform layer model does not reproduce the surface concentrations and the data is better fitted by a layer with a Gaussian distribution of segments in the aqueous phase. The benefits of the kinematic approximation are that an insight into the organisation of polymers at the air‐water interface can be obtained rapidly without the need for detailed fitting procedures inherent in the use of optical matrix methods.
Nanophases consisting of individual polystyrene molecules on mica imaged with scanning electron microscopy
Authors: Shelden R. A. , Meier L. P. , Caseri W. R. , Suter U. W. , Hermann R. , Müller M.
Published: April 2003

Scanning electron microscope images are presented of mica surfaces treated with an initiator and heated in the presence of styrene to obtain a grafted polymer. These images show “droplets” of size corresponding to that of individual polystyrene molecules. Other experimental evidence is presented which suggests that the droplets are indeed individual molecules. The images are believed to be the first ever obtained of individual, “tethered” synthetic polymer molecules.