bluuebunny/crossref_metadata_2025 huggingface dataset:
Comments on expressing the permeability of polymers to gases
Authors: Huglin Malcolm B. , Zakaria Mat B.
Published: April 2003

The fundamentals of permeability and diffusivity are presented briefly to demonstrate the possible dimensional forms available in principle for expressing the coefficients of permeability (Pm) and diffusion (Dm). The interrelation between Pm and Dm is discussed and two recent experimental methods specific to the permeation of oxygen are summarised. Twenty‐nine units appearing for Pm in the litearture are discussed and corrected where necessary. On the basis of its convenience, one particular unit is recommended and conversion factors to it are tabulated.
Polymerisation von Vinylchlorid bei Atmosphärendruck. 3. Thermische und photolytische Beständigkeit von U‐PVC
Authors: Braun D. , Holzer G.
Published: April 2003

Der thermische Abbau von U‐PVC unterscheidet sich von dem von herkömmlichem PVC dadurch, daß die HCl‐Abspaltung bereits bei 110°C mit erheblicher Geschwindigkeit abläft. Die Aktivierungsenergie der Anfangschlorwasserstoffabspaltung liegt beim U‐PVC zwischen 41,8 kJ/mol (10 kcal/mol) und 48,9 kJ/mol (11, 7 kcal/mol). Die Untersuchung der mit Tetrachlorkohlenstoff aus U‐PVC extrahierbaren Anteile mit den niedrigsten Molekulargewichten zeigt, daß diese Produkte mit 7‐fach höherer Geschwindigkeit Chlorwasserstoff abspalten als die Gesamtprobe. Diese Anteile enthalten auch eine insgesamt höhere Konzentration an Strukturunreglmäßigkeiten. Als Fehlstellen in U‐PVC, die dessen thermische Stabilität am meisten beeinflussen, müssen Verzweigungen mit tertiären Chloratomen und Doppelbindungen mit allylischem Chlor angesehen werden.

Beim Photoabbau von PVC durch UV‐Licht wird nur eine dünne, direkt der UV‐Strahlung ausgesetzte Schicht geschädigt; aus Folien von verschiedenen hergestellten PVC‐Proben wird dabei unabhängig vom Fehlstellengehalt der Polymeren mit ähnlicher Geschwindigkeit Chlorwasserstoff abgespalten.
Zno‐photocatalyzed oxidation of isotactic polypropylene
Authors: Penot Gilles , Arnaud René , Lemaire Jacques
Published: April 2003

The ZnO‐photocatalyzed oxidation of isotactic propylene appears to be a superposition of a photocatalytic oxidation of the pigmented zones and an oxidative photochemical reaction occurring in the unpigmented zones. The photoactivity of various zinc oxides produced at high and low temperatures varies at the most within a factor of 5 and is fairly independent of the surface area of the pigment. High activation energy and low initial quantum yield have been determined measuring the appearance of carbonyl compounds. The behaviour of ternary systems composed of isotactic polypropylene, zinc oxide and a typical antioxidant or hydroperoxide reducer is described. Direct interaction between the pigment and the reducing agent explains the inhibition of the oxidation of polypropylene, the inhibition of the chemical consumption of the reducer and the variations of the photoreactivities due to reheating.
Die Polymerisation von Lactamen, 66. Die cyclischen Dimeren von 8‐Octanlactam und 6‐Caprolactam und deren Einfluß auf die Autopolymerisation beider Lactame
Authors: Prokopová Irena , Kondelíková Jaroslava , Nejezchlebová Zuzana , Bíalá Jitka , Králíaček Jaroslav
Published: April 2003

Durch eine Analyse der extrahierbaren Anteile der Polymerisate von 8‐Octanlactam und 6‐Caprolactam, die in Abwesenheit von vorsätzlich hinzugefügten Initiatoren dargestellt wurden, wurde die Konzentrationsabhängigkeit der cyclischen Dimeren im Verlauf der Autopolymerisation beider Lactame verfolgt. Eine analoge Abhängigkeit wurde im Verlauf der hydrolytischen Polymerisation von 8‐Octanlactam, initiiert mit 2 mol‐% 8‐Aminooctansäure, beobachtet. Es wurde ferner der Einfluß von vorsätzlich hinzugefügten cyclischen Dimeren auf die Autopolymerisation beider Lactame untersucht.
Methacrylamide‐initiated graft copolymerisation of segmented polyurethanes
Authors: Egboh Sunday H.
Published: April 2003

Methacrylamide, which had been stored over weeks after purification polymerized spontaneously in N,N‐dimethylformamide when left standing in sealed degassed glass ampoules for several days at room temperature. However, freshly purified methacrylamide did not polymerize under identical conditions. A free radical mechanism was postulated to account for these observations. Using the self‐initiated polymerisation of methacrylamide as free‐radical sources, poly(urethane‐g‐methacrylamide)s were synthesized. Some of the resulting graft copolymers were partially soluble in certain common organic solvents. The properties of the unmodified and graft copolymers were investigated. The graft copolymers were relatively more thermally stable than the original polyurethanes.
Polymeric phthalocyanines and their precursors, 4. Optimization of electrochemical properties of polyphthalocyanine modified titanium electrodes
Authors: Wöhrle Dieter , Bannehr Rüdiger , Schumann Bernd , Jaeger Nils
Published: April 2003

Polyphthalocyanine (1) coatings on titanium foils were prepared by in situ synthesis starting from 1,2,4,5‐tetracyanobenzene (3). In order to optimize the electrochemical activity of the polymer modified electrodes several parameters, e.g. pretreatment of Ti‐foils, amount of 3, reaction temperature and time were varied. The layer of 1 was analyzed by UV/VIS‐ and IR‐spectroscopy. Electrochemical measurements were carried out in K3, K4 [Fe(CN)6] redox electrolyte. In comparison with a Pt‐electrode the polymer modified Ti‐electrodes show also high activity combined with stability. Electrodes prepared from other nitriles (4–8) were investigated in principle only.
Polypropylene modification by water‐soluble monomers in the presence of an emulsified water‐insoluble liquid phase
Authors: Citovický Pavol , Mikulášová Darina , Chrástová Viera , Mejzlík Jiří , Majer Josef
Published: April 2003

Low‐oxidized isotactic polypropylene containing hydroperoxides as well as other more stable peroxides was prepared by a contact of polymeric powder with O2/O3 mixture and was further used for chemical modification by water‐soluble monomers, such as acrylamide or acrylic acid. The reaction is performed at 30°C in the system containing water, an emulsifier, ferrous chelate, and a water‐insoluble liquid phase. In the case of acrylic acid, the use of non‐polar compounds, such as n‐hexane and benzene, is preferred, while acrylamide polymerization requires the presence of polar compounds, such as ethylacetate or higher alcohols. The composition of individual components may be optimized to such an extent that the highly predominating product of polymerization is polypropylene with bonded polar polymer branches, the simultaneously proceeding homopolymerization being strongly suppressed.
Alkaline degradation of styrene‐acrylonitrile copolymers and formation of block copolymers
Authors: Severini Febo , Pegoraro Mario
Published: April 2003

The styrene‐acrylonitrile (SAN) copolymer, dissolved in dimethylsulfoxide (DMSO), has been degraded in the presence of some bases such as KOH and potassium‐t‐butoxide at room temperature. The addition of 4‐vinylpyridine or propyleneoxide which can be anionically polymerized, has led to the production of copolymers. Their composition has been studied by IR, elemental analysis, and fractionation techniques. The presence of groups in the degraded products has been explained by a scission mechanism which gives rise to anions useful for the formation of block polymers.
Verwendung neuer halogenpolyole zur PUR‐hartschaumerzeugung mit verminderter brennbarkeit
Authors: Marzec Krzysztof , Lesiak Tadeusz
Published: April 2003

Es wurden Untersuchungen durchgeführt, inwieweit sich aus 2‐Furaldehyd erhaltenes 3,5‐Dibromhexan‐1,4‐diol, 3,5‐Dichlorheptan‐1,4‐diol, 3,5‐Dibromheptan‐1,4‐diol, 2‐(4,5‐Dichlorpentyl)propan‐1,3‐diol und 2‐(4,5‐Dibrompentyl)propan‐1,3‐diol zur Herstellung von PUR‐Hartschäumen mit verminderter Brennbarkeit eignen. Es wurde auch die Möglichkeit der Verwendung von Hexan‐1,4‐diol, Heptan‐1,4‐diol, 2‐(Pent‐4‐enyl)propan‐1,3‐diol und 6‐Hydroxymethylheptan‐1,2,7‐triol zur Herstellung von Polyurethan‐Schäumen untersucht.
Analytische Differenz‐IR‐Spektrometrie von Mehrkomponentenkunststoffen und Copolymeren. I. Identifizierung der Komponenten in Polymergemischen
Authors: Hummel D. O. , Votteler Christine
Published: April 2003

Die Einführung computerunterstützter IR‐ und FTIR‐Spektrometer hat die Möglichkeiten der qualitativen und quantitativen Analyse von makromolekularen Mehrkomponentensystemen erheblich erweitert. Wenn die Forderung der spektralen Superposition erfüllt ist, läßt sich mit Hilfe gespeicherter Standardspektren der Komponenten durch Differenzspektrometrie die Zusammensetzung eines Systems ermitteln. Da diese Forderung sehr oft nicht erfüllt ist, wählt man für die Differenzspektrometrie eines Systems aus n spektral definierten Komponenten n Punkte aus dem empirisch zu ermittelnden optimalen Bereich im Innern des (n‐1)‐dimensionalen Gibbsschen n‐Ecks. Bei realen Polymergemischen mit kristallisierbaren Komponenten ist deren Kristallinitätsgrad niedriger als in den ungemischten Polymeren; dies ist wahrscheinlich auf gegenseitige Durchdringung der nichtkristallinen Bereiche zurückzuführen. Hochgefüllte Kunststoffe lassen sich differenzspektrometrisch noch gut identifizieren, wenn der Füllstoff monodispers ist (Zahnzemente). Organisch gefüllte Werkstoffe mit niederem Bindemittelanteil (Hartfaserplatten mit Holzschliff) lassen sich nur dann differenzspektrometrisch identifizieren, wenn die charakteristischen Absorptionen des Bindemittels in Bereichen liegen, in denen der Füllstoff nicht stark absorbiert. —Artefakte können ein differenzspektrometrisches Ergebnis verfälschen. Ursachen und Auswirkungen von Artefakten werden diskutiert.
Reaction of maleic anhydride and molten polystyrene in the absence and presence of peroxides
Authors: Gaylord Norman G. , Elayaperumal Piramiah
Published: April 2003

Thermomechanical degradation of polystyrene (PS) at 180° and 250°C resulted in main chain scission and a small decrease in the molecular weight, as measured by inherent viscosity. The lower molecular weight was retained in the presence of maleic anhydride (MAH) although the latter was incorporated into the PS. The presence of benzoyl peroxide and dicumyl peroxide in the molten PS resulted in a significant molecular weight reduction, due to disproportionation of the internal radicals generated by hydrogen atom abstraction from the PS backbone. The extent of peroxide‐induced degradation was greatly reduced in the presence of MAH which presumably added to the internal PS radicals before their disproportionation. The low MAH content of the reaction product despite the use of high concentrations of MAH and peroxides is attributed to the quenching of MAH excimers by PS.
Veränderung von Polyvinylidenfluorid durch Gammastrahlen
Authors: Orth Helmut
Published: April 2003

Vinylpolymere mit substituierter alpha‐Stellung erleiden üblicherweise bei Bestrahlung einen Kettenabbau ohne Vernetzung. Die vorliegende Arbeit zeigt aber, daß Polyvinylidenfluorid unter Einwirkung von Gammastrahlen und Luftsauerstoff offenbar stark vernetzt wird, daneben findet auch Kettenabbau statt.
Water‐insoluble dextran polymers by grafting of hydrophobic groups. I. Reaction with butyric anhydride and heterogeneous hydrolysis of the partially modified dextran
Authors: Sánchez‐Chaves M. , Arranz F.
Published: April 2003

A study has been made on the modification reaction of dextran with butyric anhydride using pyridine as catalyst. The structures of the modified polymers were determined by means of IR and 1H‐NMR spectroscopy as well as by chemical analysis. It has been found a linear dependence of the reaction rate on the product of butyric anhydride and pyridine concentrations and a more complex dependence on the alcoholic groups concentration. The activation energy was found to be 7.0 kcal/mol. A partially modified dextran (D.S. 1.34) was hydrolyzed at several pH values and temperatures. The experimental data have been treated as a pseudo‐first‐order reaction with respect to the butyrate concentration. The activation energies obtained from the acid and base catalyzed hydrolysis reactions were 12.5 and 12.0 kcal/mol, respectively.
Untersuchungen zur Feinstruktur des PVC, V Herstellung von 1,2,6‐Trichlor‐n‐hexan als Modellsubstanz für niedermolekulares PVC
Authors: Schwenk Ulrich , Streitberger Horst , Weitze Renate , Wrackmeyer Bernd
Published: April 2003

Durch Umsetzung von 1,2,6‐Trihydroxy‐n‐hexan (IV) mit Thionylchlorid entsteht 1,2,6‐Trichlor‐n‐hexan (II), welches als Modellsubstanz für 1H‐NMR‐, 13C‐NMR‐und massenspektrometrische Vergleiche mit durch Extraktion und Hydrierung gewinnbarem niedermolekularem PVC dient.
Model compounds for the urea‐formaldehyde condensation. 1. Methylenediurea
Authors: Braun Dietrich , Günther Peter , Romeira Stella Maris
Published: April 2003

Methylenediurea was prepared in a manner slightly different from the methods mentioned in literature. The obtained product was characterized by chromatographic and spectroscopic methods. Hydrolyses were performed to investigate the dependence of reaction rate from pH and concentration of methylenediurea, which has been described formerly with more contaminated methylenediurea.
Graft copolymerization of acrylonitrile and acrylonitrile‐styrene onto carbon fibers containing unsaturated groups
Authors: Yosomiya Ryutoku , Fujisawa Takao , Kobayashi Masahiro
Published: April 2003

Graft copolymerization of acrylonitrile and acrylonitrile‐styrene onto carbon fibers containing unsaturated groups was studied. Graft copolymerization of acrylonitrile was found to result in a very low grafting yield in comparison with styrene, and it remained nearly constant in the latter stage of the reaction. The effects of monomer concentrations, initiators, solvents, and reaction temperature on the monomer reactivity ratios were studied by using Hayes's equation to calculate the reactivity ratio.

For graft copolymerization of acrylonitrile‐styrene were studied the rate of graft polymerization and the grafting yield with varying monomer compositions, both of which were found to be very low in the range of monomer compositions containing acrylonitrile at a level more than 8%. The monomer reactivity ratios for each monomer were calculated by use of the Fineman‐Ross method after the analytical determination of compositions of both grafted copolymer and ungrafted copolymer, and it was found that the monomer reactivity ratios for the grafted copolymer were very different from those for the ungrafted copolymer.
A porous glass fibre/resin composite: Structure, properties, and weather resistance
Authors: Järvelä Pentti K.
Published: April 2003

The structure and properties of a porous composite manufactured from glasswool and phenol‐formaldehyde resin with pressure and heat, were studied in a density range of 800 – 1500 kg/m3. Fibre structure of the composite is almost randomly orientated in two directions, and high open porosity is a typical property.

Specific strength of the composite is high compared to other similar materials, but the composite is relatively brittle. The composite is very durable in a normal atmosphere in spite of the open porosity of the composite. Only freezing water and a large enough thermal shock are capable of breaking the composite structure.
Gemeinsame Kondensation von Phenol, Melamin und Formaldehyd, II. Chromatographische und spektroskopische Untersuchungen
Authors: Braun Dietrich , Krauße Walter
Published: April 2003

Die gemeinsame Kondensation von Phenol, Melamin und Formaldehyd wurde bei unterschiedlichen Reaktionsbedingungen untersucht. Bei 100°C und pH 5 ist die Geschwindigkeit der Kondensation zwischen Melamin und Formaldehyd so extrem hoch, daß es nach wenigen Minuten zu unlöslichen, hochmolekularen Produkten kommt, die nicht mehr analysierbar sind. Bei niederigeren Temperaturen (z. B. 45°C) geht das Melamin nicht mit ausreichender Geschwindigkeit in Lösung. Daher ist es nicht moglich, bei pH 5 eine kontrollierbare Dreikomponentenkondensation durchzuführen. Im schwach alkalischen oder neutralen Medium und bei Temperaturen von 80 bis 100°C ist zwar eine kontrollierbare Umsetzung möglich, die gelchromatographischen Untersuchungen ergaben jedoch, daß das Phenol in den Reaktionsprodukten noch praktisch unumgesetzt vorlag. Lediglich einige Methylolphenole waren in sehr geringen Anteilen neben Methylolmelaminen und höhermolekularen Homokondensaten des Melamins nachweisbar. Diese Resultate wurden mit Hilfe der Dünn‐schichtchromatographie und der 13C‐NMR‐Spektroskopie bestätigt.
Effect of copolymers modifying PVC on its physical and mechanical properties and its UV‐radiation resistance, I. ESR investigation of UV‐irradiated PVC films containing MMA/MA, VC/VAC, MBS or ABS
Authors: Kaczmarek H. , Rozpłoch F. , Kamińska A.
Published: April 2003

ESR investigations of the concentration of radicals formed in UV‐irradiated PVC films containing 3 wt.‐% of one of the following copolymers MMA/MA, VCIVAC, MBS or ABS were carried out. The concentration of radicals in films containing the modifying copolymers was found to be several times higher than that in films of pure PVC. That was observed after an exposure time of 0.5, 1, 2, and 3 h. This points out that modifying copolymers considerably influence the UV‐resistance of PVC. Non‐uniform changes of the radical concentration observed in all the samples in the first stage of exposure point out that the yield of radical formation and radical desactivation is changing without domination of either of these processes. The equilibrium between these two kinds of processes was reached after longer exposure during the time apparently depending on the composition of sample.
Incorporation of ergotamine into un‐crosslinked poly(2‐hydroxyethyl methacrylate)
Authors: Huglin Malcolm B. , Sloan David J.
Published: April 2003

A simple procedure is described for producing thin polymer/drug discs of predetermined thickness, surface area and drug load. Discs were cut after solvent evaporation from a film obtained by mixing separate ethanolic solutions of poly(2‐hydroxyethyl methacrylate) and ergotamine tartrate, the latter solution containing added tartaric acid to enhance drug solubility. Established partial degradation of drug was evidenced by the colouration developed during casting. However, the calculated drug content of a disc accorded well with the total ergotalkaloids content measured by fluorescence on completely released drug.
Polypropylen‐nadelkristalle in orientierten blends aus polypropylen und poly‐1‐buten: Fourieranalyse der röntgenweitwinkelstreuung
Authors: Wenig Werner , Hagenbeck Gisela
Published: April 2003

Die laterale Dicke der Polypropylen‐Nadelkristalle in orientierten Blends aus Poly‐propylen (PP) und Poly‐I‐buten (PB‐1) wurde durch eine Analyse der Röntgenweitwinkelstreuung bestimmt. Die Nadeldicke nimmt von ca. 300 Å (Gewichtsmittel) bzw. 400 Å (Zahlenmittel) mit abnehmendem Polypropylenanteil auf ca. 100 Å ab. Mischkristalle, in denen sowohl PP‐ als auch PB‐1‐Ketten kristallisieren, werden nicht gefunden. Die Änderung der Nadeldicken mit der PP‐Konzentration erklärt die an den gleichen Proben gemessene Schmelzpunktsdepression. Die Gitterstörungen nehmen mit abnehmendem PP‐Anteil leicht zu. Sie sind im wesentlichen innerhalb einer lateralen Grenzschicht, deren Dicke nur wenig von der Nadeldicke abhängt, konzentriert.
Effect of copolymers modifying PVC on its physical and mechanical properties and its UV‐radiation resistance. II. Thermal stability of PVC films modified by MMA/MA, VC/VAC, MBS or ABS
Authors: Kamińska A. , Kaczmarek H.
Published: April 2003

Thermal stability of films made of PVC and blends of PVC and MMA/MA, VC/VAC, MBS or ABS was studied.

It was found that 1% of VC/VAC in PVC films improves its thermal stability while the other copolymers impair it.

Reverse effect, however, is observed in the test samples with increased content of copolymers from 1 to 10%. VC/VAC causes evident gradual decreases of dehydrochlorination temperature. The other copolymers cause its increase.

Hence it is that the influence of modifying copolymers on thermal stability of PVC depends not only on the type but also on the quantity of copolymer. The reason is the changing of compatibility with concentration of both polymers and therefore the changing conditions of their interaction.
Effect of pre‐extension on the electrical conductivity of styrene‐butadiene rubber loaded with FEF carbon black. II. Electrical conductivity in transverse direction
Authors: Amin M. , Hassan H. H. , Nasr G. M.
Published: April 2003

Continuing the previous work, the electrical conductivity, σ, of 70 phr FEF/SBR pre‐extended samples in the transverse direction is discussed in detail. The pre‐extension is a parameter which affects the anomalous behaviour which appeared as a minimum in the electrical conductivity σ vs. T curves. A correlation between the effect of pre‐extension on both the logitudinal and transverse direction has been done.

The dielectric constant, ϵ′ and the dielectric loss, ϵ″, of the above mentioned pre‐extended sample in the transverse direction and their dependence on temperature was observed.
Die elektrische leitfähigkeit von α,ω‐bis‐polyenen
Authors: Patschorke Joachim
Published: April 2003

Die Herstellung und Isolierung der farbigen Umsetzungsprodukte aus Maleinsäureanhydrid‐methylvinylether‐copolymerem (Gantrez AN) und aprotischen Flüssigkeiten führt zu α,ω‐Bis‐polyenen des Copolymeren mit jeweils gleichlangen Doppelbindungssequenzen, unabhängig vom Grad der Umsetzung. Der Polyenbildung in Hexamethylphosphorsäuretriamid (HMPA) geht eine chemische Umsetzung mit dieser aprotischen Substanz am Anhydridring des Gantrez AN voraus.

Werden die entstandenen α,ω‐Bis‐polyene mit Jod, Dichlor‐dicyan‐p‐benochinon (DDQ), Tetracyanoethylen (TCNE) und Tetracyanochinodimethan (TCNQ) dotiert, findet eine Verbesserung der elektrischen Durchgangsleitfähigkeit statt. Die Behandlung des undotierten α,ω‐Bis‐polyens in siedendem Xylol, wie auch Press‐Sinterung, führt zu spezifischen Widerständen in der Größenordnung von Polyacetylen (PA). Insgesamt wird der spezifische Widerstand um zehn Größenordnungen reduziert, Gantrez AN: 2,8 · 1013 Ω · cm, press‐gesintertes α,ω‐Bis‐polyen: 1,1 · 104 Ω · cm, joddotiertes α,ω‐Bis‐polyen: 2 · 103 Ω · cm.

Mit Hilfe der IR‐Spektroskopie ist es möglich, den Nachweis der Polyen‐ und Komplexbildung zu erbringen und schließlich zu zeigen, daß das leitfähigkeitsaktive Umsetzungsprodukt ein 3‐ bzw. 4‐substituiertes α,ω‐(Bis‐polyen‐)‐1,2‐polybuten ist.
Synthesis, characterization, and thermal behaviour of glycidyl methacrylate‐2‐ethoxy ethyl acrylate copolymers
Authors: Dhal Pradeep K. , Babu Gaddam N.
Published: April 2003

Copolymerization of glycidyl methacrylate has been carried out with 2‐ethoxy ethyl acrylate in bulk at 60°C using benzoyl peroxide as the initiator. The copolymer composition has been determined by chemical analysis as well as from 13C‐NMR data. The monomer reactivity ratios were calculated by using YBR method. The number average sequence length of the copolymers has been determined from 13C‐NMR data and compared with those obtained from reactivity ratios. The intrinsic viscosities of the copolymers were determined in DMF and the thermal properties of the copolymers were evaluated.
The kinetics of formation of diethylene glycol in preparation of polyethylene terephthalate and its control in reactor design and operation
Authors: Renwen He , Feng Yan , Tinzheng He , Shiming Geng
Published: April 2003

The kinetics of formation of diethylene glycol (DEG) (ether bond) which is an important side reaction in preparing polyethylene terephthalate was investigated. The following empirical rate expression is proposed for convenience of engineering applications

It has been found by experiment that n = 0.9; apparent activation energy E = 8.2 kcal/mol. The equation can be used to predict the quantity of DEG formed in the reaction. The influence of the process conditions and reactor types on DEG content in polymer are also discussed.
Untersuchung des phasenzustands von polyblock‐netzpolymeren auf der basis von oligoisoprendihydrazid und epoxidoligomeren
Authors: Lipatov Yuri , Shilov Valeri , Gomza Yuri , Kovernik Grigori , Kochetov Dimitri
Published: April 2003

Die aus Trübungspunktmessungen erhaltenen Zustandsdiagramme von Mischungen aus Oligoisoprendihydrazid und 4,4‐Dihydroxydiphenylpropandiglycidylether zeichnen sich durch einen oberen kritischen Mischungspunkt aus. Die Ergebnisse der Röntgenkleinwinkeluntersuchungen zeigen, daß während der Polymerisation eine Mikrophasentrennung der Komponenten vor sich geht. Der Mikrophasentrennungszustand bleibt im Netzpolymeren selbst bei Temperaturen erhalten, die die Homogenisierungstemperatur der Oligomermischung um 150°C überschreiten. Die Stabilität der Mikrophasenstruktur kann durch den Einfluß des dreidimensionalen Netzes chemischer Bindungen zwischen Dien‐ und Epoxidblöcken erklärt werden, was die „zwangsläufige Unverträglichkeit”︁ flexibler und starrer Blöcke verursacht.
Graft‐copolymerization of starch with acrylamide, I
Authors: Varma I. K. , Singh O. P. , Sandle N. K.
Published: April 2003

The graft‐copolymerization of acrylamide onto starch by cerium (IV) initiation has been investigated. The effect of the concentration of initiator, monomer and acid on % graft‐on has been determined. The kinetics of the acrylamide polymerization in absence and presence of starch has been studied. The maximum % graft‐on was obtained with 0.3 N HNO3, 0.005 M ceric ammonium nitrate and 1.0 M monomer concentration at 50°C.
Porous bead aliphatic‐aromatic methacrylate copolymers, I. Effect of polymerization conditions on porous structure formation of methyl methacrylate — di(methacryloyloxymethyl)naphthalene copolymers
Authors: Wójcik Anna B.
Published: April 2003

The influence of inert porogenic mixture and monomer mixture composition and concentration on specific surface areas, pore size distribution, volumes of pores capable of capillary condensation of nitrogen and true density of copolymers were investigated for a new type of methacrylate monomer system: methyl methacrylate and di(methacryloyloxymethyl)naphthalene. The obtained copolymers exhibit similar character as it is typical for PPS

PPS = Porous by Precipitant and Solvent.

styrene‐divinylbenzene resins.
Stoichiometry of sulphuric acid sorption by nylon 6
Authors: Ichimura Ayako , Iijima Toshiro , Petropoulos John H.
Published: April 2003

Sorption of sulphuric acid by Nylon 6 has been investigated. The results have been interpreted by considering the two‐step dissociation of sulphuric acid in aqueous solution. Sorption occurs predominantly in the 2H+ + SO2−4 mode, but the contribution of the H+ + HSO−4 mode becomes considerable at higher concentrations. Standard affinities for both modes have been estimated.
Synthesis and thermal properties of poly(phenoxy trifluoroethoxy phosphazenes)
Authors: Kajiwara M. , Miwa E. , Saito H.
Published: April 2003

Copolymers were prepared by the reaction of poly(dichloro phosphazene), phenoxide, and trifluoro ethoxide in THF. Elastic copolymers having lower Tg than that of poly(trifluoroethoxy phosphazene) were formed when the ratio of phenoxide: trifluoro ethoxide was between 0.5:1.5 and 1.5:0.5.
Versuche zur pfropfung von polystyrol auf rußoberflächen
Authors: Braun Dietrich , Kamprath Axel
Published: April 2003

Schlagfeste Polystyrole auf der Basis von Polybutadienkautschuk als Elastomerkomponente besitzen im Vergleich zu Standard‐Polystyrolen eine deutlich reduzierte Witterungsbeständigkeit. Einer wirkungsvollen Stabilisierung dieser Werkstoffe mit feinverteiltem Ruß steht die Tatsache entgegen, daß infolge einer mangelnden Ruß‐Polymer‐Verträglichkeit das Pigment eine Kerbwirkung zeigt, die den Hauptvorteil des schlagfesten Polystyrols — seine hervorragende Zähigkeit — deutlich vermindert. In dieser Arbeit wird über Versuche berichtet, durch Aufpfropfen von Polystyrolketten auf die Rußoberflache eine Verbesserung der Ruß‐Polymer‐Verträglichkeit und damit der technologischen Eigenschaften zu erreichen.
Incidence of heterogeneity due to polymer incompatibility on the reaction between telechelic prepolymers and on the mechanical properties of the multiblock copolymers formed
Authors: Chaumont Philippe , Beinert Gérard , Prud'Homme Christian , Herz Jean
Published: April 2003

The polycondensation reaction between telechelic poly(dimethylsiloxanes) and α,ω‐difunctional polystyrenes (or substituted polystyrenes) in toluene solution is very fast, in spite of the heterogeneous nature of the reaction medium. In the first part of the article is reported a qualitative approach of the condensation reaction in relation to the microscopic structure of the reaction medium. The second part is devoted to an investigation of the mechanical and thermomechanical behaviour of the multiblock copolymers which results from intramolecular phase separation.
Dielectric behaviour of styrene‐methyl methacrylate copolymer foams at microwave frequencies
Authors: Bandyopadhyay Pranab C. , Banthia Ajit K. , Chaki Tapan K.
Published: April 2003

Ambient dielectric effects were studied by the short‐circuited waveguide method at 9.375 GHz microwave frequency in foams from copolymers of styrene and methyl methacrylate of varying compositions, generated under identical conditions of solvent‐nonsolvent ratio, impregnation time and steaming period. The results were correlated with foam‐density, porosity and composition and were interpreted in terms of dipole‐dipole interactions and the applicability of Wiener's inequalities, logarithmic law of Lichtenecker and Rother with an empirical factor of 0.64 in the index based on the additive law of mixtures and the Böttcher‐Bruggeman's relation. Scanning electron micrography on copper‐coated fractured surfaces of the samples was done in order to examine the degree of foamability, cell‐size distribution and the mechanism of failure. Microhardness, compressive and flexural strength were also measured. Loss characteristics were similarly ascribed to copolymer foamability and dipoleorientability. A prudent choice in the monomer reactivity ratio might therefore yield an optimum reinforcement and a proper dielectric requirement suitable for electronic and radar device constructions.
Viskosimetrische bestimmung des polymerisationsgrades von oxycellulose mit hilfe der EWNN‐methode
Authors: Blaha Jan , Černý Pavel , Jahn Karel
Published: April 2003

Für die Bestimmung der Grenzviskositatszahl [η] von nitroso‐oxydierter Cellulose in verdünnter Losung wurde die EWNN Methode (alkalische Lösung eines Eisen‐Weinsäure‐Natrium‐Komplexes) angewandt. Die bisher bekannten Berechnungsmethoden von [η] mit Hilfe der Polynome für verschiedene Arten von Polymeren, verschiedene Lösungsmittel und Meßsysteme sowie auch für reine Cellulose erwiesen sich als unbrauchbar. Es wurde eine empirische Berechnungsformel in expliziter Form

mit A1 = −2,348, A2 = 3,584 und A3 = 0,006 (ηsp: spezifische Viskosität, c: Konzentration g/100 ml) vorgeschlagen, die die Berechnung von [η] bei Oxycellulose aus einer bei einer einzigen Konzentration der Probe durchgeführten Messung ermöglicht. Für die Berechnung eines Mittelwertes für den Polymerisationsgrad nach der Staudinger‐Mark‐Houwink‐Gleichung war es möglich, die für nichtoxydierte Cellulose geltende Konstante zu verwenden.
Mechanisms of degradation of cotton and effects of mercerization‐stretching upon the course of these mechanisms, part VII. Characterization of microstructural differences between scoured cotton and slack mercerized‐stretched cottons
Authors: Hebeish A. , Waly A. , Abou‐Zeid N. Y. , Ibrahim N. A. , El‐Rafie M. H. , El‐Aref A. T. , Bayazeed A.
Published: April 2003

Conditions were established to introduce almost equal and reproduciple amounts of diethylaminoethyl (DEAE) substituents into the molecular structure of scoured cotton (substrate I), slack mercerized cotton (substrate II), slack mercerized‐stretched (94%, substrate III), and slack mercerized‐stretched (103%, substrate IV) cotton. Similarities between the original structures of these substrates before and after the chemical modification were assessed by X‐ray analysis. Comparison between the DEAE cottons and the corresponding unmodified cottons upon acid hydrolysis with respect to moisture regain, loss in weight and degree of polymerization was also made. Chemical analysis was used to study the compositions and structures of the hydrolyzates (i.e., hydrocelluloses and solublized fractions) resulting from hydrolysis of the modified cottons with 2.5 N HCl under reflux for different lengths of time. Studies of rates of hydrolysis of the cellulose, rates of removal of substituted glucoses and rates of removal of individual types of substituted glucose units were considered as means to provide information regarding: (a) distribution of DEAE substitutents throughout the structure of cellulose, (b) nature of accessible regions where the DEAE substituents are developed, and (c) selective availability of the hydroxyl groups at C‐2, C‐3 and C‐6 of the D‐glucopyranosyl units in the cellulose elementary fibril.
Effect of copolymers modifying PVC on its physical and mechanical properties and its UV‐radiation resistance. III. Changes in thermal stability of PVC films modified by MMA/MA, VC/VAC, MBS or ABS induced by UV‐irradiation
Authors: Kamińska A. , Kaczmarek H.
Published: April 2003

The influence of UV‐radiation on thermal stability of PVC films, depending on the type and quantity of modifying copolymers, was studied. It was found that UV radiation can induce various changes in thermal stability of PVC decreasing its dehydrochlorination temperature T01 while increasing temperature of decomposition T02.

Particularly distinct changes in sampels containing VC/VAC indicate that even 1% of this copolymer accelerates the photodehydrochlorination and the processes which decrease the temperature of decomposition of PVC.

Smaller changes than in pure PVC in thermal parameters in samples containing ABS after irradiation show that this copolymer increases the PVC resistance to UV radiation.

Films containing MBS, ABS, MMA/MA reveal the largest changes in T01 after irradiation in the case of a content of 1% of these copolymers in the samples. In the case of bigger quantity (3 to 10%) the changes are smaller and may even diversify their direction. These copolymers, contrary to VC/VAC, make PVC films a little turbid indicating the limited compatibility of both components. Hence, the conclution is that the structure of a film, depending on compatibility of components and changing with their differing concentration, has decisive influence on the thermal and photochemical processes.
Pyrolysis field desorption mass spectrometry of polymers. III. Aliphatic polyamides
Authors: Bahr U. , Lüderwald I. , Müller R. , Schulten H.‐R.
Published: April 2003

Pyrolysis field desorption mass spectrometry has been performed from various polyamides such as nylon 6, 8, 12, and nylon 66. The pyrolytic behaviour of these compounds depends strongly on the solvent and the temperature program employed. Using formic acid as solvent strong thermal fragmentation is observed, while with 1,1,1,3,3,3‐hexafluoro‐2‐propanol almost exclusively molecular ions or cationized molecules of the monomer building block M are produced. With increasing temperature larger clusters of polymeric subunits (Mn + Na)+ are generated, but thermal fragmentation on the emitter surface also increases. The cationized molecules dominate all spectra. They are found from M3 to M5 or M15 depending on the chain length of the polymer subunit. With increasing temperature, the base peak of the spectrum is shifted to the higher mass end and small signals up to m/z 2000 and above are recorded. Thermal products are mainly formed by water elimination (−18 mu), loss of the acid amide group (−44 mu) after rearrangement and from longer polyamides by loss of the methylene groups (− 42 or 56 mu) by cis‐elimination.

These thermal fragmentations of the polymeric substances on the emitter surface can be controlled by appropriate emitter heating and correlate directly with the common chemical knowledge of these materials in the liquid or solid phase. Together with the options of integrating recording, high mass resolution and direct isotope determination, the combination of pyrolysis and field desorption mass spectrometry offers a unique tool for characterization of building blocks and high mass sequences in synthetic polymers.
Lattice expansion of the core‐fibrils in polypropylene‐poly(1‐butene) blends
Authors: Wenig Werner
Published: April 2003

Lattice parameters of the core‐fibrils in annealed polypropylene/poly(1‐butene) blends, crystallized from the oriented melt, have been measured.

The unit‐cell parameters for pure PP and PB‐1 agree well with literature values, while in the blends a lattice expansion is measured: the lattice spacings of both components increase with decreasing concentration of the respective second component.
Polymerization of lactams, 67. Modification of polyamide 6 with poly(oxyethylene) and its derivatives, part I
Authors: Cupák František , Kubánek Vladimír , Kondelíaková Jaroslava , Týfová Ilse
Published: April 2003

The polymerization of 6‐caprolactam by various mechanisms was investigated in the presence of poly(oxyethylene) (POE) of moleculare mass 1000 and 3000 terminated with hydroxyl or methoxy groups. Whereas the rate of hydrolytic polymerization (6‐aminocaproic acid as initiator) is not affected by addition of POE, the acidolytic polymerization (initiator: lauric acid) and spontaneous polymerization (without initiator intentionally added) are pronouncedly accelerated. The equilibrium content of polymer decreases with the increasing of POE concentration in initial reaction mixture in all mechanisms. A block copolymer probably results; the content of chemically bound POE is highest in the acidolytic polymerization and lowest in the hydrolytic polymerization.
Reaktive Träger mit Maleinimidgruppen zur Immobilisierung von Enzymen, 2
Authors: Manecke Georg , Middeke Hermann‐Josef
Published: April 2003

Vernetzte Copolymere aus Acrylnitril oder aus Acrylnitril und Acrylsäure wurden mit N‐Methylolmaleinimid zu maleinimidgruppenhaltigen reaktiven Trägern umgesetzt. Enzyme mit SH‐Gruppen oder solche, in die in einer Thiolierungsreaktion SH‐Gruppen eingeführt worden waren, konnten an diesen Trägern erfolgreich immobilisiert werden.
Compatibility of poly(vinyl chloride) and polyurethane blends
Authors: Shen C. H. , Wang Y. Y.
Published: April 2003

The compatibility and the mechanical properties of the blends of polyurethane (PU) elastomer and poly(vinyl chloride) (PVC) were studied. The results showed partial compatibility between PU and PVC. When the portion of PVC in blends exceeded 75%, the compatibility decreased. On the other hand, increasing the molecular weight of the glycol in PU improved the compatibility. The elongation decreased and the Young's modulus increased as the proportion of the weight of PVC in blends was increased. The tensile strength reached a minimum when PU/PVC was 50/50.
Functional metal‐porphyrazine derivatives and their polymers, 10. Secondary fuel cells based on oxygen reduction on platinum electrode modified by polymers and metal‐phthalocyanines
Authors: Hirabaru Okikazu , Nakase Tomohiro , Hanabusa Kenji , Shirai Hirofusa , Takemoto Kiichi , Hojo Nobumasa
Published: April 2003

Secondary fuel cells based on oxygen reduction of platinum electrode modified by polymers and metal‐phthalocyanine (Mt = Fe(III), Co(II), Ni(II), and Cu(II)) were studied. The discharge curves for the platinum electrode modified by poly(2‐vinylpyridine) (or polystyrene) and Co‐phthalocyanine in 30% KOH aqueous solution, for a 30 min charge at 500 μA, followed by a 100 μA discharge showed a stable plateau at about −0.24 V SCE (Saturated Calomel Electrode). The open circuit voltage (vs. Zn) of the cell was 1.2 V, and the discharge capacity was of 46 A · h/kg. For this battery there was no significant decay in its characteristics after more than 30 charge‐discharge cycles. In Mt‐phthalocyanines, the values decreased in the order of Co(II) > Fe(III) > > Cu(II) > Ni(II). From a cyclic voltammogram for the electrode modified by the polymer and Co‐Pc, the cathodic reactions were discussed.
Graft copolymerization of styrene, methylmethacrylate, and acrylonitrile onto jute fibres
Authors: Abou‐Zeid N. Y. , Higazy A. , Hebeish A.
Published: April 2003

The contribution of jute constituents, namely, water soluble matters, waxes, pectins, lignin, hemicelluloses, and α‐cellulose in the graft copolymerization reaction of jute fabric with some vinyl monomers was investigated. Styrene, methylmethacrylate, and acrylonitrile were used as the monomers and Fe2+/H2O2 redox system as initiator. The graft copolymerization reaction was carried out at 80°C using different concentrations of monomer and initiator for different lengths of time. The water soluble matters, pectins, and lignin were found to accelerate the graft copolymerization reaction during the initial stages of the reaction and in the meantime impede termination during the latter stages of the reaction. Generally, the magnitude of grafting is governed by nature of the substrate, nature of the monomer, and the conditions of the polymerization reaction. Grafting decreases the moisture regain of jute and substrates derived thereof irrespective of the monomer used within the range studied. Also, grafting decreases the tensile strength and imparts rot‐proofing properties to the substrates examined.
Porous bead aliphatic‐aromatic methacrylate copolymers, II. The estimation of the structure of methyl methacrylate—di(methacryloyloxymethyl)naphthalene copolymers by means of scanning electron microscopy
Authors: Wójcik Anna B.
Published: April 2003

Scanning electron microscopy was used to obtain complementary data concerning the surface and inner structure of porous aliphatic‐aromatic methacrylate copolymers. Depending on the amount of a porogenic (toluene and dodecane) or crosslinking agent, the suspension copolymerization of methyl methacrylate and di(methacryloyloxymethyl)naphthalene (DMN) leads to either porous polymers with measurable surface areas or gel type polymers with no measurable surface areas. Porous polymers are visualized as one or two level organization of microglobules within the beads whereas gel type polymers exhibit no pores or microglobules neither in the surface layer nor in the bead interior.
Reactive polymers, 47. Sorption properties of the reaction product of macroporous poly (glycidyl methacrylate‐co‐ethylene dimethacrylate) with 8‐aminoquinoline
Authors: Švec F. , Jehličková A.
Published: April 2003

The sorption of Fe(III), Al(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Au(III), Pd(II), Pt(IV), and Hg(II) ions on a sorbent prepared by reacting the copolymer of glycidyl methacrylate and ethylene dimethacrylate with 8‐aminoquinoline was investigated. Gold and palladium are strongly absorbed in hydrochloric acid. Results of static and dynamic tests indicate the possibility of separation of Au(III) and Pd(II) from Pt(IV) and from the other metal ions investigated in the study. The sorption of Hg(II) by the polymer increases in nitric acid.
A contribution to the study of the polymer‐filler interface in polyester and surface treated sepiolite composites
Authors: Linares Amelia , Acosta Jose Luis
Published: April 2003

The acetalation and esterification of the sepiolites with different acids and aldehydes have been carried out in order to study the interface phenomena through their technological properties. Also, a complete study of the characterization of all the organic minerals obtained has been done. It must be pointed out the strengthening effect which is produced when some of the organic minerals obtained are present in polyester compounds.
Study of the structure and properties of phosphorinated segmented polyurethanes
Authors: Vilenskyj V. A. , Kercha Y. Y. , Lipatov Y. S. , Goncharova L. B. , Grecov A. P. , Shapoval R. L.
Published: April 2003

The effect of an expanded set of physical bonds in rigid polyurethane segments has been studied by X‐ray measurements, thermography, thermomechanics, etc. It has been shown that, by varying the nature and structure of quaternizing agent, the structure and properties of the segmented polyurethanes can be purposefully varied. Heat treatment (annealing) of polyurethanes, and polyurethane‐ionomer samples has proved that the growth of hard domains is first of all due to the rigid segments associating with hard domains already existing.
Studium der alkalischen hydrolyse der ester‐bindungen in einem acrylsäureethylester‐acrylnitril‐divinylbenzol‐perlcopolymeren
Authors: Matějíaček Alois , Seidl Josef , Krejcar Emil , Matyáš Josef
Published: April 2003

Aufgrund der Resultate früherer Arbeiten wurde die mathematische Auswertung der bei der alkalischen Hydrolyse der Ester‐Bindungen von Acrylsäureethylester‐Acrylnitril‐Divinylbenzol‐Perlcopolymeren erhaltenen Zeit‐Umsatz‐Kurven durchgeführt. Der Einfluß der Reaktionstemperatur, des molaren Verhältnisses zwischen den Bestandteilen des reagierenden Systems, der Perlgröße des Copolymeren und seiner Vernetzungsdichte wurde mit Hilfe der Reaktionskonstanten und der Diffusionskoeffizienten verfolgt.
Characterization of nylon 6 fibers grafted by acrylic monomers
Authors: Mukherjee A. K. , Goel H. R.
Published: April 2003

Samples of nylon 6 fibers grafted with the acrylic monomers methyl methacrylate (MMA), ethyl methacrylate (EMA), and n‐butyl methacrylate (n‐BMA) with various graft levels were investigated by infrared, X‐ray and scanning electron microscopic studies and the changes due to grafting with respect to the parent nylon 6 fibers were studied.

The IR spectra of grafted nylon 6 samples show that there is a little change in the peak heights by grafting of nylon 6 with various monomers. The characteristic peaks of parent nylon are, more or less, maintained in the case of grafted samples. A peak at 1730 cm−1 of the ester group was noted which confirms that the polymer has been grafted with the monomer.

X‐ray diffraction data on the grafted samples show some remarkable variations with the degree of grafting, depending upon the nature of the graft monomer. The percentage of crystallinity varies with the degree of grafting. In the initial stages of grafting it shows a decrease in the case of PMMA graft and an increase in the case of PEMA and Pn‐BMA graft. At higher degrees of grafting (above 50% graft add‐on) the percentage of crystallinity decreases in all the three cases. Orientation index has been found to increase in the initial stages of grafting in the case of EMA and n‐BMA grafted nylon 6 and it decreases later on, whereas in the case of MMA graft it decreases continuously even at low graft level.

The studies of surface characteristics for the parent and grafted samples show that spectacular changes on the surface of the various samples have taken place. With the increase in the graft level the diameter of the fiber increases and also the voids and cracks appear on the surface.
Wasserlösliche kationisch modifizierte copolymere mit acrylamid
Authors: Okay Oguz , Schindlbauer Hellmuth
Published: April 2003

Die Copolymerisation von Acrylamid mit N‐[3‐(N′‐Diethyl‐N′‐methyl)ammoniumn‐propyl]‐maleinimid‐methylsulfat in Aceton/Wasser‐Gemischen mit Persulfat‐Initiator führt zu pulverförmigen kationischen Polymeren mit hoher Molmasse, die leicht wasserlöslich sind und sehr gute Ausflockungseigenschaften zeigen. Das Copolymere weist praktisch die gleiche Zusammensetzung auf wie das eingesetzte Monomerengemisch. Sowohl die Ausbeute als auch die Molmasse des Copolymeren steigen mit zunehmender Acetonmenge (bis ca. 52 Vol.‐%) im Lösungsmittelgemisch an.