bluuebunny/crossref_metadata_2025 huggingface dataset:
The reaction of pyromellitic dianhydride with 4,4′‐diaminodiphenylmethane
Authors: Marek M. , Bednář B. , Králíček J.
Published: April 2003

The homogeneous polyaddition reaction of pyromellitic dianhydride with 4,4′‐diaminodiphenylmethane was investigated. The dependence of the number average molecular weights on time has a maximum; low equilibrium values of M̄n are caused by a disturbed equimolarity of functional groups due to the hydrolysis of dianhydride with water present in the solvent. In the course of establishment of the equilibrium M̄n value, the molecular weight distribution changes to the most probable value.
Zusammenhänge zwischen mechanischem Verhalten und Morphologie von eigenfaserverstärkten Poly(propylen)/Poly(1‐buten)‐Blends, kristallisiert aus der hochorientierten Schmelze
Authors: Wenig Werner , Schöller Thomas
Published: April 2003

Mechanische Parameter wie Elastizitätsmodul, Fliß‐ und Bruchspannung von aus der hochorientierten Schmelze hergestellten nadelkristallinen Mischungen aus Poly(propylen) und Poly(1‐bute) wurden mit morphologischen Parametern, die aus Röntgenmessungen abgeleitet wurden, korreliert. Es wird gezeigt, daß der Elastizitätsmodul des Verbundes aus den E‐Moduln der Fasern und der Matrix berechnet werden kann (Mischungsregel). Die an der Probe angreifenden Kräfte werden voll auf die Fasern übertragen; der Verbund kann daher als eigenfaserverstärktes System angesehen werden. Die Abschätzung der kritischen Faserlänge ergibt, daß die Festigkeit der FAsern voll ausgenutzt wird; der Bruch des Systems bei Belastung ist daher auf das Versagen der Fasern zurückzuführen. Das mechanische Verhalten des Verbundes wird stark beeinflußt durch die Komponentenzusammensetzung. Die longitudinale Struktur der Nadeln beider Komponenten bleibt unbeeinflußt von der jeweiligen Co‐Komponente.
Studies on rubber bound antioxidants
Authors: Avirah S. , Joseph R.
Published: April 2003

Antioxidants were attached to hydroxy‐terminated liquid natural rubber by modified Friedel‐Crafts alkylation reaction using anhydrous zinc chloride as catalyst. The rubber bound antioxidants were found to be less volatile and less extractable compared to conventional antioxidants. The bound antioxidants were tried both in latex compounds and dry rubber compounds. The vulcanizates showed improved ageing resistance compared to vulcanizates based on conventional antioxidants.
Studies on PE‐HD/PE‐LLD blends
Authors: Kurian P. , George K. E. , Francis D. Joseph
Published: April 2003

A high density polyethylene grade is blended with two selected grades of linear low density polyethylene and the mechanical and rheological properties of the blends are evaluated over the entire composition range. The blends show sufficient compatibility in the solid phase and in the melt and hence they can be advantageously used to capitalize on their useful properties.
Synthese und Modifizierung polymerer Kationenleiter auf der Basis von Poly(glycerinformal)
Authors: Fritz Heinz P. , Stein Klaus
Published: April 2003

Durch ringöffnende Polymerisation von Glycerinformal (GF) mit Alkalimetallen (M) in flüssigem Ammoniak konnten kationisch leitende Polymere (MxPGF) synthetisiert werden. Die Leitfähigkeiten κ hängen vom Alkoholatanteil im Polymeren ab. Na0,1PGF zeigt ein κRT = 3,75 · 10−4 S/cm. Poly(glycerinformal)‐Alkoholate lassen sich mit CO2, CS2, oder SO2 zu entsprechenden Halbestersalzen umsetzen. Das PGF‐O‐Sulfonat (NaSO2)0,1PGF ist bis 100°C thermostabil und hat ein κRT = 6,5 · 10−4 S/cm.
Interpenetrating polymer networks of polyurethanes and epoxy resin, I. Mechanical behavior
Authors: Hsieh K. H. , Chiang Y. C. , Chern Y. C. , Chiu W. Y. , Ma C. C. M.
Published: April 2003

The interpenetrating polymer networks (IPNs) prepared from polyurethane (PU) and a glycidyl ether of phenol formaldehyde (GEPF) were synthesized by using a simultaneous polymerization method. The effects of PU molecular weight and amount on the mechanical property are discussed. For the PU/GEPF IPNs based on polyester‐type PU, as the PU content was increased, the tensile strength and fracture energy decreased, but the impact strength increased significantly. However, for the PU/GEPF IPNs based on polyether‐type PU, the extent of heterogeneity was decreased with decreasing molecular weight of polyether polyol in PU and the tensile strength and fracture energy were enhanced. The impact strength increased to a maximum value and then decreased when the PU content was further increased.
Effects of long‐chain alkyl peroxydicarbonates on the properties of PVC produced by suspension polymerization
Authors: Arslanalp Caner , Erbay Erol , Bilgiç Tülin , Savaşçi Ö. Tunç
Published: April 2003

Commercially available diethyl, dicetyl, and dimyristyl peroxydicarbonate initiators are investigated in a commercial PVC suspension polymerization receipe. Diethyl peroxydicarbonate, which is formed in situ by the reaction of hydrogen peroxide, lime, and ethylchloroformate, produced PVC with less “fish‐eyes”, whereas it has the disadvantage of being toxic and gives inconsistent polymerization times, therefore the reactor efficiency decreases. Dicetyl and dimyristyl peroxydicarbonates are solid, less toxic materials easy to handle, therefore, when these initiators are used, consistency between batches is obtained. However, PVC with coarse particle sizes containing considerable amounts of “fish‐eyes” is obtained, which eventually causes processing problems. It is found that particle coarsening occurs as a result of water soluble impurities of initiators, and “fish‐eyes” occur as a result of morphological changes. When dicetyl and dimyristyl type initiators are used, the number of non‐porous PVC particles increases. This structure heterogeneity causes formation of ungellified spots, so‐called “fish‐eyes”, during processing. It is found that the non‐porous particles are formed due to accumulation of an excessive amount of initiator in a single vinyl chloride monomer droplet.

When the distribution of these solid initiators is homogenized by adding them in solution, the formation of non‐porous particles is inhibited. However, the coarsening effect still remains, which could be eliminated by extraction of initiator solutions with water just before they are fed to the reactor. Extraction also decreases the amount of crust formation.
Die Vernetzung von Perfluoralkenen aus dem strahlenchemischen Abbau von Polytetrafluorethylen zu höhermolekularen Carbonylverbindungen
Authors: Bürger Wolfgang , Lunkwitz Klaus , Platonov Viatscheslav E.
Published: April 2003

Grundlage der Untersuchungen waren mittels Elektronenstrahlung aus PTFE‐Abfällen gewinnbare Gemische von Perfluoralkenen. Untersuchungen am Perfluorhept‐1‐en zeigten, daß terminale Perfluoralkene bei der Reaktion mit difunktionellen Partnern bevorzugt ungesättigte Ether‐ bzw. Amidstrukturen ausbilden. Die Reaktion des Perfluoralkengemisches mit Nucleophilen führt zur Vernetzung, wobei primär Additionsprodukte der terminalen Perfluoralkene mit Aminen oder Phenolen/Alkoholän zu Carbonylverbindungen hydrolysieren und Allylstrukturen ausbilden. Innenständige Perfluoralkene des Gemisches bzw. Allylprodukte addieren das Nucleophil and lagern sich teilweise zu stabilen Vinylprodukten um. Es entstehen gemischte Ether‐Esterstrukturen bzw. ungesättigte Polyamide, wobei das Dinucleophil wesentliche Eigenschaften der Fluorverbindung bestimmt. Thermisch und auf chemischem Wege entstehen durch Mehrfachsubstitution hochvernetzte Strukturen, die neue Wege für Fluorcarbonausru‐stüngen eröffnen.
Synthesis and characterization of polymers containing naphthyl‐2H‐benzotriazoles, 2. Polymer synthesis and characterization
Authors: Rasoul F. A. , Shuhaibar K. F. , Attari A. , Pasch H.
Published: April 2003

2‐(2‐Hydroxy‐7‐(meth)acryloyloxynaphthyl)‐2H‐benzotriazoles were polymerized and copolymerized with styrene and methyl methacrylate in dichloromethane using azoisobutyronitrile as the initiator. The polymer composition was determined by UV spectroscopy and compared with elemental analytical data; the molecular weights were determined by GPC. In homopolymerization, low molecular weight products were obtained due to the bulky naphthyl‐2H‐benzotriazole units. In the case of copolymerization with methyl methacrylate it was found, that the composition of the polymers was very close to the initial ratio of the monomers, whereas in copolymers with styrene the amount of incorporated benzotriazole was higher.
Poly[1‐(2‐hydroxyethyl) aziridine] as polychelatogen for liquid‐phase polymer‐based retention (LPR)
Authors: Geckeler Kurt E. , Rivas Bernabé L. , Zhou Rongnong
Published: April 2003

The metal complexing properties of poly[1‐(2‐hydroxyethyl) aziridine] for the metals Co(II), Zn(II), Ni(II), Cu(II), Cr(III), Fe(III), Cd(II), Pb(II), and Sr(II) in aqueous phase were investigated. The LPR method is based on the retention of inorganic ions by soluble polymers in a membrane filtration cell and subsequent separation of low‐molecular species from the polymer complex formed. The metal interaction with the hydrophilic polymer was determined as a function of pH and filtration factor. According to the interaction pattern obtained, Cu(II) forms the most stable complexes with the polyaziridine within the pH range 3 to 7. At pH 3, it is possible to separate Cu(II) from all other metal ions. Sr(II) is only slightly retained at the pH range investigated. At pH 7, all elements, except Sr(II), did interact with the polymer and were almost quantitatively retained.
A rapid estimation of mechanical performance from hardness
Authors: Saini D. R.
Published: April 2003

This paper presents a method to estimate the stress‐strain curves of polymer materials of different hardnesses by relating stress‐strain measurements to hardness measurements. Its application is demonstrated for three thermoplastic materials.
Interpenetrating polymer networks of polyurethanes and epoxy resin, II. Compatibility and morphology
Authors: Hsieh K. H. , Chiang Y. C. , Chern Y. C. , Chiu W. Y. , Ma C. C. M.
Published: April 2003

The interpenetrating polymer networks (IPN) of polyurethanes (PU) and a glycidyl ether of phenol formaldehyde (GEPF) were prepared by a simultaneous polymerization method. The dynamic mechanical properties and morphologies of the IPNs were investigated. It was found that multiphased morphology was formed in the PU/GEPF IPNs. With the PU based on polyester‐ or polyether‐type polyols, the dynamic mechanical analysis (DMA) of these IPNs exhibited various shifts in the loss moduli (E″) of the high and low temperature transition domains depending upon the types and molecular weights of the polyols employed in the PU. Three distinct transition domains were observed as the PU content increased up to a certain level.
Extrusion behavior of starch graft copolymers: Starch‐g‐polystyrene and starch‐g‐poly(methyl acrylate)
Authors: Henderson Alex M. , Rudin Alfred
Published: April 2003

Starch‐g‐polystyrene and starch‐g‐poly(methyl acrylate) copolymers were synthesized and extruded without separating homopolymer PS or PMA. The extrusion behavior resembled that of thermoplastic melts in that these products were shear thinning and exhibited significant extrudate swelling and entrance pressure losses in capillary flow. These and other observations indicate that the materials comprise deformable polymer‐grafted starch particles suspended in the corresponding homopolymer melt. Flow is apparently by superparticle, rather than continuum melt mechanisms.
Das spezifische volumen geschmolzener polymerer in abhäungigkeit von druck und temperatur
Authors: Busch Bernhard , Lechner Manfred D. , Kleintjens Ludovicus A.
Published: April 2003

Bei der industriellen Herstellung von polymeren Werkstoffen ist eine möglichst genaue Kenntnis des spezifischen Volumens v in Abhängigkeit vom Druck p und von der Temperatur T erforderlich. Dafür ist ein sogenannter „Biegeschwinger”︁ entwickelt worden, mit dem man v im Bereich von 1 bis 800 bar und von 20 bis 200°C ermitteln kann. Dieses wird an Testmessungen mit destilliertem Wasser bewiesen. Am Beispiel von fünf flüssigen Polymeren und Copolymeren wird die Brauchbarkeit sowohl empirischer als auch theoretisch fundierter Zustandsgleichungen überprüft. Dabei zeigt sich, daß die rein empirische Tait‐Gleichung und die zum Teil theoretisch fundierte Simha‐Somcynsky‐Gleichung mit sechs bzw. fünf anpasbaren Parametern die Meßwerte am besten beschreiben.
Optimal monomer addition policies for composition control of emulsion terpolymers
Authors: Arzamendi Gurutze , De la Cal José C. , Asua José M.
Published: April 2003

An approach for the calculation of the optimal monomer addition policies for polymer composition control in emulsion terpolymerization is presented. The model allows the calculation of the composition of the initial charge of the reactor and the time dependent monomer addition rates. Monomer addition strategies for reactors with limited capacity for heat removal were obtained. A heat removal rate dependent on the latex solids content was considered. Simulation showed that the present approach leads to the production of homogeneous terpolymers in process times which are significantly shorter than that required by the classical starved process to produce a terpolymer of similar homogeneity.
Synthesis and characterization of polymers containing naphthyl‐2H‐benzotriazoles, 3. Hydrogen bonding in monomers and polymers containing naphthyl‐2H‐benzotriazole
Authors: Pasch H. , Shuhaibar K. F. , Rasoul F. A.
Published: April 2003

The UV absorption characteristics of a number of dihydroxynaphthyl‐2H‐benzotriazoles, their (meth)acryloyloxy derivatives and the corresponding polymers have been studied in a range of solvents of different polarity. It was shown that the formation of hydrogen bonds in these compounds strongly depends on the polarity of the solvent and an equilibrium exists between intramolecular and intermolecular hydrogenbonded states. The stability of the intramolecular hydrogen bond was determined quantitatively. The equilibrium between the intramolecular and the intermolecular hydrogen‐bonded state of the molecule was strongly affected by the chemical structure of the naphthyl‐2H‐benzotriazole. The stability of the intramolecular hydrogen bond increased when electron‐donating substituents were introduced into the benzotriazole or when the naphthyl‐2‐benzotriazole was fixed to a polymer backbone.
Characterization of ultra low density polyethylenes (PE‐ULD)
Authors: Kim Byung Kyu , Kim Myun Soo , Jeong Han Mo , Kim Kook Joong , Jang Jae Kwon
Published: April 2003

Ultra low density polyethylene (PE‐ULD), the newest and most recently commercialized member of polyethylene family, has been characterized in terms of structure, thermal and rheological properties, and molecular parameters. Since the prime use of PE‐ULD is polyolefin modifier, emphasis is put on the melt rheology of the samples to provide data base for blending with other resins.
Studies on new non‐shrinking, thermally stable, araldite‐type photopolymers with pendent arylacryloyl groups III. Photopolymers with pendent cinnamic acid ester and furan acrylic ester groups and their reactions with low molar mass modifiers
Authors: Budde Klaus , Quella Ferdinand , Mathes Alfred , Melchior Walter , Müller Harald , Nuyken Oskar , Spiegel Sabine
Published: April 2003

Commercially available Araldite™‐type polymers have been modified with cinnamic and furan acrylic acid chlorides. The polymers were photochemically crosslinked via a [2 + 2] cycloaddition. The resulting polymers show glass transition temperatures up to 130°C and dielectrical constants of ϵr = 3.0. Therefore, these polymers can be applied as permanent resists in multi‐layered wiring structures. Numerous well‐defined multifunctional modifiers have been synthesized. The effect of those modifiers on the polymerization and properties of the araldite‐type polymers has been studied in some detail.
Synthese und charakterisierung von butadien‐divinylbenzol‐copolymeren
Authors: Burghardt Kathrin , Häusler Karl‐Georg , Martl Michael Gerd , Hummel Klaus , Gebauer Ulrich , Gehrke Klaus
Published: April 2003

Im Rahmen von Arbeiten zur Modifizierung des cis‐1,6Polybutadiens wurde die Copolymerisation von Butadien und einer Divinylbenzolfraktion, insbesondere der Bereich mit kleinen Divinylbenzolgehalten, untersucht. Neben dem Ziegler‐Natta‐Katalysator Nickeloctanoat/Bortrifluoridetherat/Aluminiumtriethyl kam auch ein Nickeloctanoat/Titantetrachlorid/Aluminiumtriethyl‐System zur Anwendung, welches es durch seine höhere Aktivität gegenüber Vinylaromaten ermöglicht, großere Mengen der Divinylbenzolfraktion zu polymerisieren. Durch die Anwendung von spektroskopischen, pyrolysegaschromatographischen und thermoanalytischen Charakterisierungsmethoden können Beziehungen zwischen den erhaltenen Glas‐, Kristallisations‐ und Schmelztemperaturen und der Mikrostruktur des Polymeren hergestellt werden. Es zeigt sich, daß sowohl das Divinylbenzol als auch die trans‐1,4 bzw. die 1,2‐Vinyl‐Einheiten statistisch in das Polymere eingebaut werden. Damit eignet sich neben der Pyrolysegaschromatographie besonders die Differential Scanning Calorimetry als eine einfache Methode zur Charakterisierung der Struktur von aus technischen Fraktionen erhaltenen und teilweise vernetzten Polymerproben.
Morphologiebildungs‐ und dispergiermechanismen bei der herstellung und verarbeitung von polymer‐blends aus acrylnitril‐butadien‐styrol‐(ABS)‐ bzw. Styrol‐acrylnitril‐(SAN)‐copolymerisaten mit thermoplastischem polyurethan (TPU)
Authors: Radusch Hans‐Joachim , Hendrich Rea , Michler Goerg H. , Naumann Irene
Published: April 2003

An ABS/TPU‐ bzw. SAN/TPU‐Blends wurden Untersuchungen zur Morphologiebildung beim Schmelzemischen auf der Basis der Analyse des viskoelastischen Verhaltens der Komponenten angestellt. Unter definierten Bedingungen im Laborkneter gemischte und unter definierten Bedingungen mittels Hochdruckkapillarviskosimeter extrudierte Blendproben wurden hinsichtlich ihrer Phasenmorphologie elektronenmikroskopisch charakterisiert. Die mittels der rheologischen Analyse prognostizierten Morphologietypen und Morphologiebildungsmechanismen konnten anhand der elektronenmikroskopischen Aufnahmen und der quantitativen Morphologieanalyse bestätigt werden. Es zeigte sich, daß das Viskositätsverhältnis der Komponenten primären Einfluß auf die Morphologiebildung ausübt. Darüber hinaus sind auch thermomechanisch induzierte molekulare Abbauvorgänge und thermodynamische Wechselwirkungen sowie damit im Zusammenhang stehende Kristallisationsbedingungen für die TPU‐Phase hinsichtlich der resultierenden Phasenmorphologie nicht zu vernachlässigen.
Photoinitiated surface grafting of synthetic fibers, I. Photoinitiated surface grafting of ultra high strength polyethylene fibers
Authors: Feng Zhenguo , Rånby Bengt
Published: April 2003

Photoinitiated surface grafting of acrylic monomers has been carried out onto high strength polyethylene (HSPE) yarn by means of a continuous process. The grafting reaction is initiated by UV irradiation of the yarn after presoaking in an acetone solution of initiator and monomer. Four initiators, benzophenone (BP), 4‐chlorobenzophenone (4‐CBP), 2‐hydroxy‐2‐cyclohexylacetophenone (HHA), and 2,2‐dimethoxy‐2‐phenylacetophenone (DMPA), and two monomers, acrylic acid (AA) and acrylamide (AM), have been used. After short irradiation time (10 to 20 s) successful grafting is obtained, as shown by ESCA and IR‐ATR spectra, dye adsorpotion from aqueous solution, and measurements of adhesion of single filaments to epoxy resin. Grafting efficiency of 74% has been reached for AA as monomer (26% is homopolymer). The tensile strength and modulus of the HSPE yarn are retained in the grafting process. The degree of surface grafting is mainly a function of structure and concentration of monomer and photoinitiator in the presoaking solution and of the irradiation conditions used. Increasing irradiation time gives increasing amounts of grafted polymer up to a certain limiting value. The reactivities of the four initiators have been compared showing the highest grafting yields of AA with BP and of AM with 4‐CBP as photoinitiator. AA grafted HSPE yarn can be dyed to rather deep color by dipping in an aqueous solution of Crystal Violet. Increased dye absorption by a factor of up to seven has been measured for yarn grafted with AA to the maximum level obtained. The filaments of the grafted yarn show increased adhesion to epoxy resin by a factor of up to five compared with the ungrafted filaments.
Water‐soluble polyamides as potential drug carriers, V. Carboxy‐functionalized polyaspartamides and copolyaspartamides
Authors: Machado M. De L. , Neuse E. W. , Perlwitz A. G.
Published: April 2003

Poly‐α,β‐D, L‐aspartamides featuring carboxy‐functionalized side groups are synthesized by three different preparative routes: (i) aminolytic ring opening in polysuccinimide, (ii) N‐carboxymethylation of amine‐functionalized polyaspartamides, and (iii) nucleophilic addition of iminodiacetic acid to acryloylamino‐substituted poly‐aspartamides. The polymeric products, possessing inherent viscosities in the wide range of 5–30 ml g−1, are characterized microanalytically and spectroscopically. By virtue of the carboxylic acid side groups lending themselves to the reversible covalent bonding of suitably structured drug models, the polymers are designed to function as macromolecular carriers of chemotherapeutically active agents. Being perfectly soluble in aqueous media over a wide pH range, they fulfill a crucial precondition for carrier components in (parenterally administered) polymer‐drug conjugates.
Untersuchungen von dünnen filmen auf basis von poly(p‐phenylen‐1,3,4‐oxadiazolen)
Authors: Schulz Eckhard , Leibnitz Eberhard , Bauer Albrecht , Schmolke Rudolf
Published: April 2003

Es wird über die Herstellung und Charakterisierung von dünnen Filmen aus Poly(p‐phenylen‐1, 3,4‐oxadiazolen) berichtet. Die aus H2SO4‐Lösungen präparierten Filme besitzen eine gute optische Transparenz und sind mechanisch stabil. Filme aus Michungen mit Polyamiden zeigen ein ähnliches Verhalten und sind aufgrund ihrer thermischen Eigenschaften für spezielle Anwendungen interessant. Bei faserverstärkten Filmen zeigen erste Untersuchungen, daß spezielle Grenzflächenbereiche entstehen.
2,3‐dihalogen‐1,4,7‐heptantriole als flammschutzmittel in PUR‐hartschäumen
Authors: Marzec Krzysztof
Published: April 2003

Die Verwendbarkeit der aus 2‐Furaldehyd erhaltenen Halogentriole 2,3‐Dichlor‐ und 2,3‐Dibrom‐1,4,7‐heptantriol als reaktive Flammschutzmittel für PUR‐Hartschäume wurde untersucht. Zur Modifikation der Schäume wurden diese Verbindungen allein und im synergistischen System mit Antimontrioxid verwendet.
Preparation of multiphase block copolymers by redox polymerization process
Authors: Hazer Baki , Cakmak Ismail , Denizligil Selcuk , Yagci Yusuf
Published: April 2003

Redox polymerization of methylmethacrylate (MMA) using Ce(IV) with poly(oxyethylene) having azo and hydroxy functions was carried out to yield methylmethacrylate‐ethylene glycol block copolymers with labile azo linkages in the main chain. These prepolymers were used to initiate the radical polymerization of styrene through the thermal decomposition of the azo group, resulting in the formation of multiblock copolymers. Successful blocking has been confirmed by fractional precipitation, a strong change in the molecular weight distribution and spectral measurements.
Monodisperse polymer beads as packing material for high‐performance liquid chromatography. Synthesis and properties of monidisperse polystyrene and poly(methacrylate) latex seeds
Authors: S̆migol Vladmír , S̆vec Frantis̆ek , Hosoya Ken , Wang Qing , Fréchet Jean M. J.
Published: April 2003

The effects of initiator concentration, ionic strength of polymerization medium, polymerization temperature, and monomer/water phase ratio on particle size, particle size distribution and molecular weight of the resulting polymers prepared by an emulsifier‐free emulsion polymerization of styrene, methyl methacrylate and glycidyl methacrylate have been studied. Optimal conditions for preparation of uniformly sized polystyrene particles larger than 1 μm have been found. An attempt to synthesize monodisperse particles of similar size from methacrylate monomers and crosslinked particles has failed. It is shown that the swelling ability of “non‐activated” latex particles does not exceed 70 fold increase in the volume and strongly depends on the size of the original particles.
Die kristallisation eines geschmolzenen molekülkomplexes aus hochmolekularem polyoxyethylen und harnstoff
Authors: Bogdanov Bogdan , Michailov Marin , Uzov Christo , Gavrailova Girka
Published: April 2003

Die Strukturveränderungen eines Molekülkomplexes (MK) aus Polyoxyethylen und Harnstoff beim Abkühlen aus dem geschmolzenen Zustand werden kalorimetrisch und röntgenographisch untersucht. Es wird festgestellt, daß eine polymorphe Hochtemperaturform des MK entsteht, die beim Abkühlen in die bekannte Kristallform des MK mit hexagonaler Kristallmodifikation übergeht.
Synthese und koagulationsverhalten von hydrophilen copolymeren des acrylnitrils
Authors: Fritzsche Peter , Dautzenberg Herbert , Nötzel Petra , Rother Gudrun
Published: April 2003

Copolymere des Acrylnitrils (AN) mit variabler Molmasse bzw. mit variablem Anteil von Acrylsäuremethylester (ASME) und Natriumallylsulfonat (NaAS), Acrylamid (AA), Itaconsäure (IS), Polyethylenglykolacrylat (600) (PEGA), Vinylacetat (VA), Acrylsäure‐2‐hydroxyethylester (HEE) oder Natrium‐2‐acrylamido‐2‐methylpropansulfonat (NaAMPS) wurden hergestellt, wobei die erforderlichen Polymerisations‐bedingungen mit Hilfe eines mathematischen Polymerisationsmodells ermittelt wurden.

Die Fällungsuntersuchungen mit der Methode der Lichtstreuung zeigten, daß NaAS und NaAMPS einen dominierenden Einfluß haben. Bei Acrylnitril‐Homopolymeren tritt eine harte Fällung auf, und die entstehenden Partikel haben eine Dichte zwischen 0,2 und 0,4 g/cm3. Zunehmender NaAS‐bzw. NaAMPS‐Gehalt führt ab einem Gehalt von beispielsweise ca. 0,8 Gew.‐% NaAS im Monomergemisch zu einer weichen Fällung, bei der hochgequollene Partikel mit einer Dichte in der Größenordnung von < 1.10−2 g/cm3 entstehen. Ein Einfluß der Molmassen und des ASME‐Gehaltes Konnte nicht nachgewiesen werden. Beim Acrylnitril/Acrylamid‐System genügen offensichtlich 0,5 Gew.‐% Allylsulfonat im Monomeransatz, um eine stabile, weiche Fällung unter Bildung hochgequollener Strukturen zu gewährleisten. Alle Proben mit den übrigen hydrophilen Cokomponenten zeigen ohne NaAS bzw. NaAMPS‐Comonomer ein hartes Fäungsverhalten mit wenig gequollenen Partikeln.
DSC investigation on the thermal degradation of PVC in blends
Authors: Braun Dietrich , Kömmerling Stefan
Published: April 2003

The thermal degradation of poly(vinyl chloride) (PVC) has been studied by differential scanning calorimetry (DSC). Due to crosslinking, the glass transition temperature (Tg) of PVC raises during the degradation. The thermal degradation of PVC has also been studied for heterogeneous 1:1 (w/w) blends of PVC with polystyrene (PC), poly(styrene‐co‐acrylonitrile) (SAN), high‐impact PS (poly(styrene‐g‐butadiene)) (HIPS) and poly(SAN‐g‐butadiene) (ABS). Tg of the PVC phase raises slower during degradation in the PVC/PS‐blend, whereas in the other blends the crosslinking is accelerated, due to a negative influence of the double bonds and/or the nitrile groups on the thermal stability of PVC. Since most methods use the determination of eliminated HCl to study the degradation of PVC, the DSC method is very useful in investigations on PVC‐containing polymer blends, if there might be a reaction of HCl with one of the blend components.
Polyacetal/poly(tetrafluoroethylene) blends, I. The effect of Na‐treated poly(tetrafluoroethylene) on polyacetal
Authors: Chiang Wen‐Yen , Huang Chi‐Yuan
Published: April 2003

The various properties of the blends of polyacetal (POM) with up to 20 wt.‐% chemically surface‐treated poly(tetrafluoroethylene) (CPTFE) were investigated and compared with those of POM/PTFE blends. The PTFE is added to POM to improve the wear properties, however, the mechanical properties of POM/PTFE blends decrease with increasing PTFE content, but tensile strength and Young's modulus of POM/CPTFE blends are more than 2 times higher than that of the POM/PTFE blends. SEM shows that the size of inherent agglomerative PTFE is in the range of 30 to 100 μm. The particle size of major CPTFE dispersed in POM is smaller than 1 μm.
Synthesis and properties of cationic amine‐epoxy adducts and their use in electrodeposition, II. Diethanolamine/diketimine terminated cationic epoxy resins with pendent 2‐ethylhexanol‐blocked TDI groups
Authors: Yang Chin‐Ping , Chen Yahn‐Haur
Published: April 2003

A diglycidylether of bisphenol A epoxy resin (DGEBA) was first reacted with 2,4‐toluene diisocyanate partially blocked with 2‐ethylhexanol (2‐EH P. B. TDI) to form modified epoxy resins, and subsequently reacted with different molar ratios of diethanolamine and bis(2‐methylisobutylketiminoethyl)amine (DKI) (used as ring opening agents) to give diethanolamine/diketimine terminated resins. These resins were hydrolyzed and neutralized with acetic acid to give cationic resins containing various contents of primary amine groups in the terminal polymeric chain. These cationic resins can be dissolved in a suitable solvent and mixed with deionized water to obtain emulsions. The electrodeposition properties and characteristics of the resulting cationic resins were investigated in detail. The effects of hydrophobic solvents, such as hexyl cellosolve (HCS) and toluene, on the deposition properties of the emulsions are discussed.
Relation between polymer surface tension and orientation of thermotropic liquid crystals
Authors: Seeboth Arno M.
Published: April 2003

The orientation (tilt angle φ) of thermotropic liquid crystals (LC) on the interface to a polymer‐coated surface is not only determined by the numerical value \documentclass{article}\pagestyle{empty}\begin{document}${\rm \gamma }_{\rm S} {\rm }\left( {{\rm \gamma }_{\rm S} {\rm = \gamma }_{\rm S}^{\rm d} {\rm + \gamma }_{\rm S}^{\rm p} } \right)$\end{document} of the substrate surface tension. However, the ratio between the dispersive and the polar part of \documentclass{article}\pagestyle{empty}\begin{document}${\rm \gamma }_{\rm S} {\rm }\left( {{\rm\gamma }_{\rm S}^{\rm d} {\rm : \gamma }_{\rm S}^{\rm p} } \right)$\end{document} also influences the LC orientation on the substrate surface. A polyimide and an amide‐modified styrene/maleic anhydride copolymer were used as polymers.
On the polymerization of acrylonitrile in the presence of some unsaturated triazine derivatives
Authors: Konstantinova Temenoujka , Grabchev Ivo
Published: April 2003

The polymerization of acrylonitrile in the presence of some unsaturated, triazinebased fluorescent brighteners (FB) has been investigated. It was found colourimetrically that more than 80% of the FB is incorporated in the polymer. The initial concentration of 0.1 wt.‐% is sufficient to obtain a good bleaching effect without significant decrease of the molecular weight.
Photoinitiated surface grafting of synthetic fibers, III. Photoinitiated surface grafting of poly(ethylene terephthalate) fibers
Authors: Feng Zhenguo , Rånby Bengt
Published: April 2003

Photoinitiated surface grafting of acrylic acid (AA), acrylamide (AM) and 4‐vinyl pyridine (VP) onto poly(ethylene terephthalate) (PET) fibers (a commercial textile yarn) has been studied using benzophenone (BP) as photoinitiator. A continuous process as previously described has been applied, which involves presoaking of the PET yarn in a solution of initiator and monomer in acetone and UV irradiation in nitrogen atmosphere. The resulting grafted polymer on the fiber surface has been analyzed by ESCA, titration of carboxy groups (grafted AA), and dye absorption. The relative ESCA intensities (RI) of O1s/C1s and N1s/C1s are used as measure for grafted AA, AM and VP, respectively, after recording the RI‐values for ungrafted fibers. For grafting with AA, the RI‐values increased from 32.8% (background) to 48.6% after 20 s irradiation time. The amount of carboxy groups measured by titration increased from 0.045 to 0.106 mmol/m2. Assuming an even coverage of grafted AA polymer, this means a grafted layer of 4.8 nm thickness. After grafting, the adsorption of the dye Crystal Violet (CV) from aqueous solution increased by about 3 times. With AM as monomer, the RI‐values increased from 2.6 (background) to 14.8% and the adsorption of a direct dye Sirius Lichtbordo B‐LL increased by about 6 times. With VP as grafted monomer, the RI‐values increased from about 2.6 (background) to 5.1% and the adsorption of the direct dye increased by about 4 times.
Studies on hexolic anhydride based polyesters, II. Thermogravimetric analysis
Authors: Sivasamy P. , Palaniandavar M. , Vijayakumar C. T.
Published: April 2003

Unsaturated polyesters based on hexolic anhydride (5,6,7,8,9,9‐hexachloro‐1,2,3,4,4a,5,8,8a‐octahydro‐5,8‐methanonaphthalene‐2,3‐dicarboxylic anhydride), maleic anhydride, phthalic anhydride, cis‐2‐butene‐1,4‐diol, 2,3‐dichloro‐2‐butene‐1,4‐diol and 2,3‐dibromo‐2‐butene‐1,4‐diol were synthesized. The thermal behaviour of the polyesters was studied using thermogravimetric technique. The results were compared with those available for other hexolic anhydride and HET‐acid (1,4,5,6,7,7‐hexachlorobicyclo[2.2.1]hept‐5‐ene‐2,3‐dicarboxylic acid) based polyesters. The direct study and comparative study of the polyesters revealed that the bromodiol is prominent in increasing the flame retardant character of the polyesters in which it is incorporated; alkenic diols are inferior compared to saturated diols regarding the thermal stability of the polyesters; as the number of carbon atoms in the saturated diol increases, the stability and flame retardancy of the polyesters decrease; branching in the diol part decreases the stability of the polyesters, with hexolic anhydride based polyesters being thermally more stable than HET‐acid based polyesters.
Oberflächenstrukturierung polymerer Fasern durch UV‐Laserbestrahlung. 13. Oberflächenstrukturierung von Hochleistungsfasern
Authors: Kesting Wolfgang , Knittel Dierk , Bahners Thomas , Schollmeyer Eckhard
Published: April 2003

Die Oberflächenbehandlung von unterschiedlichen Hochleistungsfasertypen mit gepulstem UV‐ Laserlicht wird untersucht. Bedingt durch die hohen UV‐Absorptionskoeffizienten dieser Materialien wird der bekannte Effekt des UV‐laserinduzierten Abtrags (Ablation) bei allen Fasern beobachtet. Zusätzlich werden durch die Relaxation der orientierten Makromoleküle charakteristische Strukturierungen auf der Faseroberfläche ausgebildet. Für einen möglichen kontrollierten und gezielten Einsatz dieser physikalischen Oberflächenmodifizierung in textilen Anwendungen werden die gnaunen Bedingungen der Laserbestrahlung ermittelt und beschieben. Darüber hinaus werden geeignete Konstanten der Laserbearbeitung wie Ablationsschwellenenergie, Ätzraten und Strukturierungskonstanten für verschiedene Fasertypen bestimmt.
Studies on hexolic anhydride based polyesters, III. Mechanistic and comparative aspects of the product distributions in the thermal degradation
Authors: Sivasamy P. , Palaniandavar M. , Vijayakumar C. T.
Published: April 2003

Two systems of unsaturated polyesters based on maleic anhydride, phthalic anhydride, hexolic anhydride (5,6,7,8,9,9‐hexachloro‐1,2,3,4,4a,5,8,8a‐octahydro‐5,8‐methanonaphthalene‐2,3‐dicarboxylic anhydride) and 2‐butene‐1,4‐diol or 2,3‐dichloro‐2‐butene‐1,4‐diol were synthesized. The polyesters were pyrolysed under programmed heating from 40° to 400°C at a rate of 10 K/min. The volatile pyrolysates were separated and identified by combined gas chromatography/mass spectrometry. The formation of anhydrides, diols, hydrocarbons, chloro compounds and polychlorinated cyclopentadiene compounds etc., is explained in the light of single and double β‐scission, acyl‐oxygen and alkyl‐oxygen bond fission and carbon‐carbon bond homolysis mechanisms. It is observed that β‐scission plays a vital role in the primary degradation process of polyesters. The decreasing number of β‐hydrogens in the diol part of the polyester is reflected in the quantity of anhydrides ejected from the polymer backbone. Further it is observed that hexachlorocyclopentadiene and related compounds are ejected from the hexolic anhydride set free during pyrolysis and not from the hexolic moiety incorporated in the polymer backbone. An approximate calculation shows that about 75% of the total amount of maleic anhydride, formed in the pyrolysis of saturated diol based polyesters having fullest number of β‐hydrogens in the diol part, is derived from β‐scission and the rest via alkyl‐oxygen bond fission mechanism. A similar observation is also noted‐indirectly for the formation of hexolic anhydride.
Dielectric study of acetylated cotton cellulose and saponified cellulose acetate
Authors: Saad Gamal R. , Botros Maged G. , Nessim Refaat I.
Published: April 2003

Dielectric relaxation data are reported at frequencies of 0.1 – 10000 kHz over a temperature range of 10–80°C on cellulose acetates of different degrees of substitution, and on saponified cellulose acetate. The acetyl substitution is found to remove the low‐frequency relaxation process, γ, previously observed in medicated cotton cellulose, and to affect the other higher‐frequency process, β, in different ways, depending on the acetyl content. Conversely, saponification of cellulose acetate leads to the reversion of these two processes but with different features.

Analysis of the absorption bands is made, and an assessment of the results obtained is given.
Removal of methyl orange by a system of insoluble chloromethylated poly(styrene‐co‐2‐methyl‐2‐oxazoline)
Authors: Tashiro T. , Thirvenkatam P.
Published: April 2003

A study was made of the removal of methyl orange (MO) solutes in water by the reaction product (CMPS‐MeOZO) of chloromethylated, divinylbenzene‐crosslinked polystyrene (CMPS) with 2‐methyl‐2‐oxazoline (MeOZO).

The removal behavior was examined with regard to the conformity to the Freundlich adsorption formula and the Klotz equation, and noted to conform in wider range of initial concentration of MO to the former than to the latter. Removal rates and amounts removed were larger in CMPS‐MeOZO(3)‐Hy (hydrolyzate of CMPS‐MeOZO(3)) than in CMPS‐MeOZO(4). This is attributable to the less cationic charge of the nitrogen atoms in poly(N‐acetyliminoethylene) than that of poly(iminoethylene) side chains.
Metallization of polyacrylonitrile by reduction of polymer‐incorporated metal ions
Authors: Yosomiya Takatoshi , Ono Hitoshi , Yosomiya Ryutoku
Published: April 2003

The film properties and ionic conductivity behavior of polyacrylonitrile (PAN) containing various metal salts were investigated. Further, with a newly developed process, it was possible to cover the surface of polymer with a metallic layer. From water contact angle measurements it was found that the surface structure of PAN containing metal salt was greatly affected by properties of the material in contact with during film preparation. Ionic conductivity behaviors near Tg differed between the PAN containing a metal chloride and that containing a metal perchlorate; the activation energy for the rubber‐like state (ϵr) was greater than that for the glassy state (ϵg) with the former and ϵr < ϵg with the latter. It was clarified that a metal layer was formed on the polymer surface at a relatively low temperature by a reduction treatment with NaBH4 aqueous solution.
Preparation of polystyrene resin with pendant vicinal dioxime groups
Authors: Biçak Niyazi , Atay Tülay , Koza Güneş
Published: April 2003

Preparation of macroporous polystyrene beads having pendant vicinal dioxime groups and their metal chelating ability is described. Acetylated polystyrene resin crosslinked with 2 mol‐% divinyl benzene was oxidized with SeO2 to give the polymer bearing glyoxyloyl side groups. Then, treating with hydroxylamine, the polymer possessing dioxime groups was obtained. Metal absorbtivity and decomplexation of the resulting polymeric resin were investigated in a wide pH range.
Etude de l'oxydation de polystyrènes chlorométhylés renfermant de nouveaux radicaux tétrathiafulvalénylcarbonyloxyméthyles
Authors: Mora Henri , Fabre Jean‐Marc , Giral Louis , Montginoul Claude , Sagnes René , Schué François
Published: April 2003

Les polystyrènes chlorométhylés renfermant des radicaux tétrathiafulvalénylcarbonyloxyméthyles peuvent être oxydés. Ainsi la formation de sels d'ions radicaux obtenus à partir de ces polymères et de tétrabromure de carbone, irradiés sous UV, a été mise en évidence. Des complexes de transfert de charge ont été préparés en mettant en présence ces polymères et de la 2,3‐dichloro‐5,6‐dicyanobenzoquinone. La présence de sulfoxydes non décelés et résultant de l'oxydation de certaines unités de tetrathiafulvalène contenus dans ces polymères pourrait expliquer les problèmes rencontrés lors de la filtration de leurs solutions.
Preparation and uranyl ion adsorptivity of macroreticular chelating resins containing phosphono groups
Authors: Park In‐Hwan , Jung Jin‐Chul , Hwang Sung‐Chan , Joo Jae‐Oh
Published: April 2003

Macroreticular copolymer beads were prepared by suspension polymerization of styrene, bis(2‐chloroethyl) vinyl phosphonate (CEVP) and divinylbenzene (DVB) in the presence of toluene as diluent. The bis(2‐chloroethyl) phosphonate groups on the bead surface were converted into phosphono groups by hydrolysis with dilute nitric acid. For the additional enrichment of phosphono groups, the copolymers were phosphorylated at the phenyl rings with phosphorus trichloride in the presence of aluminum chloride and hydrolyzed and oxidized with dilute nitrics acid. The investigations on metal ion chelation characteristics of the bead‐type copolymers revealed that they have very high adsorptivity toward uranyl ions and good chemical resistance under acidic and alkaline media. It was also found that the phosphono group‐containing copolymer beads are effective adsorbents for other heavy metal ions such as Pb2+, Hg2+, Cd2+, and Cu2+.
Isocyanate reactions in and with N,N‐dimethylformamide
Authors: Joel Detlef , Müller Petra , Ahl Rosemarie
Published: April 2003

Solutions of phenylisocyanate (I) in DMF were stored at different temperatures in the presence of both polyurethane catalysts and 1,3‐diphenylurea (II). The reaction products were determined by HPLC. Beside the hydrolysis of I to II, a significant reaction of I with II to 1,3,5‐triphenylbiuret (III) was observed at 20°C. Above 60°C, I reacted with the solvent to form N,N‐dimethyl‐N′‐phenylformamidine (V). In DMF, III dissociated to I and II already at temperatures >40°C.
Zur vernetzung dünner polymerschichten durch photolyse aromatischer bisazide
Authors: Reinisch Gerhard , Wigant Lothar , Hiller Wolf , Schmolke Rudolf
Published: April 2003

Die UV‐Vernetzung in 1 μm‐Schichten aus Polymeren verschiedener Konstitution, die 10 Gew.‐% 4,4′‐Diazidobiphenyl (DABP) enthalten, wird zeitabhängig anhand der reduzierten Schichtdicke nach Lösungsmittelbehandlung verglichen. Für die hohe Vernetzungsgeschwindigkeit von Polyglycidylmethacrylat mit den photolytisch gebildeten Bisnitrenen sind die 1,2‐Epoxypropylgruppen verantwortlich. Der Oxiranring bleibt erhalten (IR‐Spektroskopie). Wahrscheinlicher Reaktionsort ist die exocyclische CH2‐Gruppe (13C‐Festkörper‐NMR‐Spektroskopie).
Investigation of synthesis and light stability of polymeric azo dyes. I. Polymeric urethane‐azo dyes
Authors: Lewandowsky Ekkehart , Mayer Roland , Marx Jörg , Böttcher Horst
Published: April 2003

Starting from 10 different 4′‐substituted 4‐[N,N‐dihydroxyethyl]aminoazobenzenes, polymeric urethane‐azo dyes (M̄n 42000–10200) were prepared by reacting those with hexamethylene diisocyanate. The dependence of spectral properties, redox potentials and photofading behaviour on the kind of substitutents was determined and then compared with corresponding monomer and dimer model compounds. Photofading is caused by a photooxidative process. In the sequence of monomeric > dimeric > polymeric azo dyes, light stability decreases due to a diminution in thermal disactivation processes and in a possible intramolecular energy transfer.
Effect of electron radiation on dyed PET and PA 66 substrates
Authors: Clauss Bernd , Weiss Mathias
Published: April 2003

PET and PA 66 fabrics were dyed with different disperse dyes under regular conditions. The dyed fabrics were irradiated with 180 kV electron radiation. It was observed that increasing radiation doses led to increasing total color differences dE if compared to the unirradiated materials.

These color differences are mainly caused by two types of reactions. First by the reversible formation of dye radicals, which can be reoxidized (in air) to the original dye molecules, and second by the irreversible reaction of dye molecules with the fiber polymer. The latter reaction causes a permanent change of the color of the fabric, which can be kept low with the proper irradiation conditions. The decision whether or not this change can be tolerated depends on the further use of the textile.
Preparation of porous bead cellulose with technical grain size
Authors: Lenfeld Jiří , Peška Jan , S̆tamberg Jiří
Published: April 2003

Bead cellulose, particle diameter 0.1 – 2.7 mm, was prepared from dispersions of viscose in chlorobenzene by applying the thermal sol‐gel transition. Technical viscose containing modifiers Berol Visco 32, Berol Glyco 1540 and Kordamin V was used. The size of cellulose beads can be controlled by means of the amount of oleic acid in the dispersion medium. The optimal result was reached at 5 – 6 mg oleic acid in 90 ml chlorobenzene.
Hydroformylation of nitrile rubber and its characterization
Authors: Bhattacharjee Susmita , Bhowmick Anil K. , Avasthi B. N.
Published: April 2003

Selective homogeneous catalytic hydroformylation of nitrile rubber (NBR) has been carried out in presence of trans‐chlorocarbonylbis(triphenylphosphine)rhodium(I) [trans‐RhCl(CO)(PPh3)3] and hydridocarbonyltris(triphenylphosphine)rhodium(I) [RhH(CO)(PPh3)3] as catalysts. At 363 K, under 5.6 MPa pressure (CO:H2 = 1:1) in presence of 0.43 mmol/l catalyst, the amount of hydroformylation is 25% in the case of trans‐RhCl(CO)(PPh3)2 and 30% in the case of RhH (CO)(PPh3)3 for NBR with 40 mol‐% acrylonitrile. Reaction kinetics suggest that both the reactions are pseudo‐first order with respect to olefinic substrate and catalyst concentration. The rate of the reaction is higher in the case of RhH(CO)(PPh3)3. The characterization of the products by IR and NMR spectroscopy shows the formation of internal aldehyde groups from 1,4‐units and terminal branched aldehyde groups from 1,2‐units of the copolymer. Measurements on intrinsic viscosity [η] and glass transition temperature (Tg) suggest a decrease in [η] and an increase in Tg with the degree of formyl functionalization. Gel formation has been observed at higher degree of hydroformylation.
Synthesis and exchange reactions of polymers containing reactive phthalimide groups
Authors: Mahmoud Amal Ahmed , Shaaban Abd‐El‐Fattah Fadel , Khalil Ahmed Abd‐El‐Salam , Messiha Nagi Naguib
Published: April 2003

N‐Methacryloyloxyphthalimide (NMPI) and N‐methacryloyloxytetrabromophthalimide (NMTPI) were prepared by the reaction of methacrylic acid with N‐hydroxy‐phthalimide and N‐hydroxytetrabromophthalimide, respectively. The resulting monomers were polymerized. The reactions of the resulting polymers with hydroxy and amine compounds have been studied.
The elastic constants of moulded polymeric composites
Authors: Jian Nianbao , Zhang Mingqiu , Zeng Hanmin
Published: April 2003

The paper makes an approach to the determination of the five independent elastic constants of uniaxial symmetric material with the ultrasonic immersion technique. Only five ultrasonic wave velocities are required during measurement. The elastic constants of the moulded composites comprised of poly(phenylene sulfide), poly(aryl ether sulfone) with cardo side groups, short carbon fiber and carbon black are measured by using the suggested treatment. The results exhibit a close relationship between the elastic properties and the structure of the materials.