bluuebunny/crossref_metadata_2025 huggingface dataset:
Multimerisation: Assoziation und aggregation von makromolekülen. V. Assoziation „ataktischer”︁ polypropylene
Authors: Elias Von Hans‐Georg , Dietschy Hansjörg
Published: April 2003

Das Lösungsverhalten von Polypropylenen unterschiedlicher Konfiguration und verschiedenen Molekulargewichtes wurde untersucht. Die hochmolekularen isotaktischen Polypropylene zeigen zeitabhängige Aggregation. Die niedermolekularen, ätherlöslichen Fraktionen wiesen Konzentrationen an isotaktischen Triaden zwischen 0 und 73% auf. Sie erwiesen sich in allen untersuchten Lösungsmitteln (Benzol, Toluol, Cyclohexan, Methylcyclohexan, Brombenzol, Tetrachlorkohlenstoff und Trichloräthylen) nach dampfdruckosmotischen Messungen als assoziiert. Die Gleichgewichtskonstanten der Assoziation lagen zwischen 20 und 82000 l. mol−1. Die Messungen in Brombenzol folgten der VAN'T HOFFschen Gleichung nicht. Aus den thermodynamischen Daten wurde auf einen Desolvatationsprozeß als treibende Kraft für die Assoziation geschlossen. Die Assoziationskonstanten nehmen mit steigender Konzentration an isotaktischen Triaden ab.
Graft copolymerization of methyl methacrylate onto cellulose
Authors: Namasivaya D. , Patnaik B. K. , Thampy R. T.
Published: April 2003

Methyl methacrylate has been grafted onto cellulose pulp using manganic ion as the initiator. The variable parameters studied are initiator and monomer concentrations, temperature and reaction time. The grafting efficiency, degree of grafting and frequency of grafting are found to be dependent on the above mentioned variables.
Polymerization of methyl methacrylate initiated by 3.3.4.4‐tetraphenyl hexane and 1.1.2.2‐tetraphenyl cyclopentane
Authors: Borsig E. , Lazár M. , Čapla M.
Published: April 2003

The kinetics of polymerization initiated by mono‐ and biradicals formed by decomposition of 3.3.4.4‐tetraphenyl hexane (TPH) resp. 1.1.2.2‐tetraphenyl cyclopentane (TPCP) have been investigated. The results point to a larger participation of the biradicals from TPCP in the termination reactions than of the monoradicals with TPH. It has been further established that with both above mentioned initiators the usual rate increase in consequence of the gel effect does not occur. On the other hand, in both cases a considerable growth of the average molecular weights takes place in the course of polymerization.
Über probleme der kationischen polymerisation des caprolactams. I. Die polymerisation mit caprolactam‐hydrochlorid
Authors: Doubravszky Von Sándor , Geleji Frigyes
Published: April 2003

Wir untersuchten die Caprolactampolymerisation mit Caprolactam‐hydrochlorid mit Hilfe der dilatometrischen Methode. Auf Grund des Zusammenhangs zwischen Geschwindigkeitsmaximum und Katalysatoranfangskonzentration sollten beide funktionelle Gruppen der bei der Initiierungsreaktion entstandenen Produkte am Kettenwachstum teilnehmen. Nach dem Maximalwert zu Reaktionsbeginn sinkt die Polymerisationsgeschwindigkeit bis zu einem Minimum und wächst dann wieder bis zum Erreichen eines stationären Wertes. Der Gesamtcharakter der kinetischen Kurven deutet darauf hin, daß der Polymerisationsmechanismus verwickelt ist und sich wahrscheinlich das Kettenwachstum nicht auf dem Wege ein und desselben Elementarschrittes abspielt.
A theoretical interpretation of the BUECHE‐HARDING master curve
Authors: Conti W. , Gigli I.
Published: April 2003

The extension of the BUECHE theory to heterogeneous polymers is performed by assuming that (a) the maximum relaxation time of the fractions is proportional to the 4.5 power of the molecular weight and (b) the same mixing rule for the fractions is valid at every shear rate. For bulk polymers the Mn and Mw mixing rules are considered. For values of η/η0 ≥ 0.2 and 3 ≥ Mw/Mn ≥ 1.2 the flow curves of the heterogeneous polymers may be expressed by means of the following equation:

where the δ and K values are dependent on the heterogeneity ratio Mw/Mn, the mixing rule, and the type of molecular weight distribution. (erfc = complementary function to error function).

The BUECHE‐HARDING standard curve is very close to an erfc function and by comparing it with our theory it can be proved that the BUECHE‐HARDING curve is the flow curve of a polymer with Mw/Mn = 1.20. Consequently we have MR = Mw or MR = 0.58 Mw whether the Mw or Mn mixing rule is considered.

Experimental data is compared with the theoretical results and this comparison is discussed.
Étude de la cristallisation des polyèmres. III. Détermination de la température de fusion et cinétique de fusion isotherme des polyoxyéthylènes de faible masse moléculaire
Authors: Spegt Par P. A. , Terrisse J. , Gilg B. , Skoulios A.
Published: April 2003

On décrit dans ce travail une étude dilatométrique de la fusion isotherme de polyoxyéthylénes de faible masse moléculaire. On a interprété les données expérimentales en supposant que seule la vitesse d'évacuation de la chaleur gouverne la cinétique de fusion.

On a déterminé la temipérature de fusion des polyoxyéthylénes en fonction de la masse moléculaire et on en a déduit le rapport de l'énergie de surface et de l'enthalpie de fusion.
Monodisperse polymers by anionic polymerization
Authors: Guzmán G. M. , Bello A.
Published: April 2003

Nearly monodisperse styrene and methyl methacrylate polymers of high molecular weight have been prepared by anionic polymerization at low temperatures. A. single‐stage vapour addition method has been used to mix the catalyst and monomer. Styrene was polymerized by Na‐biphenyl in tetrahydrofuran, and methyl methacrylate by Li‐biphernyl in dimethoxyethane as the solvent. The poly(methyl methacrylate) was syndiotactic. Deviations from ideal monodispersity and the appearance of bimodal distributions have been interpreted in terms of two kinds of active centers during polymerization: ion‐pairs and free anions. A quantitative estimate of both kinds has been carried out.
Über substituierte polystyrol‐phenyl‐disulfimide
Authors: Koch Von Ursula , Wolf Friedrich , Skilandat Peter
Published: April 2003

Es wurden Polystyrol‐phenyl‐disulfimide hergestellt, die im Phenylkern durch Methyl‐Chlor‐ oder Carboxylgruppen substituiert waren. Die Bestimmung der thermischen Beständigkeit ergab keine Verbesserung gegenüber dem unsubstituierten Polymeren.
Bemerkung zur molekulargewichtsbestimmung nach TRAUTMAN
Authors: Sutter Von W. , Burchard W.
Published: April 2003

An verschiedenen Systemen werden Messungen mit Hilfe des TRAUTMAN‐Verfahrens vorgenommen und die Ergebnisse mit denen von Sedimentationsgleichgewichts‐ und Sedimentationsgeschwindigkeitsmessungen verglichen. Während die Ergebnisse der YPHANTIS‐ und Sedimentationsgeschwindigkeitsmethode gut übereinstimmen, ergeben sich nach dem TRAUTMAN‐Verfahren große Unterschiede sowohl im Molekulargewicht als auch in der Konzentrationsabhängigkeit des scheinbaren Molekulargewichts.
Cyclopolycondensations. IV. Investigation of the polymerization mechanism of aromatic diaminodicarboxylic acid in polyphosphoric acid and the thermal stability of aromatic polyamide amino acids
Authors: Kurihara Masaru , Yoda Naoya
Published: April 2003

In order to elucidate the reaction mechanism of the polyphosphoric acid solution Polymerzation of aromatic diaminodicarboxylic acid, a model reaction with anthranilic acid in Polyphosphoric acid was studied. It was established that the polymerization procceds via the formation of phosphorylated reaction intermediates followed by self‐polycondensation to form high molecular weight aromatic polyamides containing benzoxazinone rings along the polymer main chain. The effect of additives such as benzidine and naphthalene was studied, and the mechanism of polymerization is discussed based on the elementary analyses and on infrared spectral and proton magnetic resonance spectral data. Furthermore, the thermal stability of aromatic polyamides was determined by thermogravimetric and differential thermal analyses, and the crystallinity of the polymer was measured by X‐ray diffraction.
The mechanism of dispersion of starch by urea and by guanidinium and lithium salts
Authors: Erlander Stig R. , Tobin R.
Published: April 2003

The ability of various aqueous salt solutions to disperse high‐amylose corn starch (70 % apparent amylose) was examined. The results were interpreted in light of a proposed theory concerning the structure and properties of hydrated ions and molecules. In those solutions where both cation and anion have negative hydration (possess only B‐regions) such as guanidinium thiocyanate, the solubility of starch continues to increase to the saturation point of the salt. On the other hand, if the cation has positive while the anion has negative hydration, then the solubility of starch goes through a maximum (at 6 M LiBr or 6 M LiSCN). It is proposed that only the negatively hydrated domains of a salt disperse starch. The negatively hydrated domains of an anion or cation disperse starch granules in one of two ways. If the effective dielectric constant of the ion is greater than that of water, then the dispersion occurs by swamping out the electrostatic forces involved in a hydrogen bond. If the effective dielectric constant of the negatively hydrated ion is less than that of water, then the ion can disperse starch granules only when it becomes unhydrated as in the case of 9 M LiCl. In other words, dispersion occurs by hydrating the hydroxyl groups to the ions. Such electrostatic interactions may be involved in some proteinpolysaccharide complexes.
Polymerisation von Lactonen 7. Mitt.: Polymerisation von β‐trichlormethyl‐β‐lactonen
Authors: Ohse Von Helmut , Cherdron Harald
Published: April 2003

Es wurde die Polymerisierbarkeit folgender, nunmehr leicht zugänglicher, β‐Lactone untersucht: β‐Trichlormethyl‐β‐propiolacton (TCPL), β.β‐Bis(trichlormethyl)‐β‐propiolacton (HCPL) und α.α‐Dimethyl‐β‐trichlormethyl‐β‐propiolacton (DMTCPL). Lediglich von TCPL und DMTCPL konnten Polymere erhalten werden, und zwar nur mit kationischen Initiatoren. HCPL dagegen polymerisierte unter den gleichen Bedingungen nicht.
Sur le mécanisme du gonflement des hauts polymères cristallins par les solvants
Authors: Descamps‐Carlier J. , Homès G. A. , Point J. J.
Published: April 2003

Specimens of polyethylene laminated at room temperature and annealed at 110°C were swelled at 85°C by biphenyl and then quickly allowed to cool to room temperature.

X‐ray diffraction studies at large and low angles revealed that during the cooling process, biphenyl crystallizes into flat crystals of about 10 Å thickness, located between the polyethylene single crystals. The swelled specimens are friable. It is possible to desaggregate them into single crystals as shown by electron diffraction. Swelling does not affect the texture of the initial polyethylene specimens which is that of a b̄ axis fibre. Further more during the cooling process the orientation taken by the biphenyl crystals depends only on the polyethylene texture. The texture of biphenyl is that of a b̄ axis fibre parallel to the polyethylene fibre.
Condensation polymerization of N‐dithiocarbonyl alkoxyearbonyl amino acids. Part V. Studies on reaction mechanism
Authors: Kato H. , Higashimura T. , Okamura S.
Published: April 2003

N‐Dithiocarbonyl ethoxycarbonyl amino acids (DTE‐amino acids) (I) are easily converted to high molecular polypeptides by heating in dioxane. To elucidate the reaction mechanism, the formation of by‐products or intermediates in the polymerization of DTE‐glycine and ‐alanine were studied. Thiazolid‐2.5‐dione (IV) and 2‐thio‐oxazolid‐ 5 ‐one (III) were isolated as by‐products. (III) is unstable and changes to polypeptide and (IV). The IR‐absorption of a isothiocyanate group is observed keeping (I) and (III) in KBr disks at room temperature and in the initial stage of the polymerization of (I). These results suggest the following predominant mechanism for the formation of poly‐peptides proceeding via the isothiocyanate carboxylic acid (II):
magnified image
Osmometry with membrane‐permeating solutes of low molecular weight
Authors: Coll H.
Published: April 2003

Experimental osmotic pressure (p)‐time (t) curves for several low‐molecular weight Solutes in toluene were studied by means of a recording automatic osmometer. The results for a monodisperse solute can be expressed by p = r π exp (−αt), with π the theoretical osmotic pressure. In the case of more than one solute the pressures are additive. for a given set of experimental conditions, the parameters r and α depend on the molecular weight of the solute, but to some extent also on its structure. It is shown how an approximate estimate of molecular weight and concentration of a polymer additive can be made from p versus t plots in the course of a molecular weight determination of the polymer.

The results could not be brought in agreement with the equation of HOFFMANN and UNBEHEND. Also, the assumptions underlying the theory of LAIDLER and SHULER do not seem to be adequate in the general case to relate α to r.
Mechanical relaxation in poly(2.6‐dimethyl‐1.4‐phenylene oxide) in the glassy state
Authors: de Petris S. , Frosini V. , Butta E. , Baccaredda M.
Published: April 2003

Dynamic mechanical properties (sound velocity, v, and damping factor, Q−1) have been determined in poly(2.6‐dimethyl‐1.4‐phenylene oxide) over a wide range of temperature (from 80 to 500°K) at acoustic frequencies.

The examined polymer exhibits two mechanical relaxation effects, one, α, at temperatures above 480°K, characterized by a sudden strong drop of the elastic modulus and by a rapid increase of the damping factor with increasing temperature, and another, β, below the glass transition point, Tg, characterized by a small drop of the elastic modulus, between 290 and 370°K, and by a damping maximum at about 370K (fm = frequency corresponding to the maximum ⋍ 7000 Hz).

The α relaxation effect has been attributed to the thermal excitation of cooperative motions in the chain, while the secondary β relaxation has been interpreted as due to oscillation of aromatic rings around COC bond. The damping maximum, for the lateer, is shifted toward higher temperatures with increasing frequency, following an ARRHENIUS‐type equation with an apparent activation energy of about 20 kcal/mole.
On the polymerization and copolymerization of sulfolenes
Authors: Goethals E. J.
Published: April 2003

3‐Sulfolene is not polymerizable at temperatures below 80°C with radical or ionic catalysts. At 100°C or higher and in the presence of AIBN polybutadienesulfone is formed. Attempts to copolymerize 3‐sulfolene with various vinyl compounds were unsuccessful. Likewise 2‐sulfolene is not polymerizable; but it was possible to copolymerize it with acrylonitrile or vinyl acetate. The reactivity ratios were found to be: r (vinyl acetate) = 1.52 ± 0.12; r (2‐sulfolene) = 0.0 ± 0.1. A transfer mechanism with 2‐sulfolene is discussed.
Studies on polymers from cyclic dienes. VII.. Cationic polymerization of methylcyclopentadiene
Authors: Aso Chuji , Ohara Osamu
Published: April 2003

Polymerization of methylcyclopentadiene was carried out with FRIEDEL‐CRAFTS catalysts. The monomer contained 1‐methyl and 2‐methyl isomers only. No isomerization of the monomer occurred during polymerization. All the polymers obtained were soluble in organic solvents such as toluene. The rate of polymerization and the intrinsic viscosity of the polymer decreased with increasing concentration of 1‐methylcyclopentadiene in the monomer feed. The structure of the polymer was determined by NMR spectroscopy and it was shown that most of the 1‐methylcyclopentadiene units were incorporated as the 3.4‐structure, 70 to 95% of the 2‐methylcyclopentadiene units as the 1.4‐structure and the residual part as the 3.4‐structure. The ratios of the 1.4‐ and 3.4‐structures of the 2‐methylcyclopentadiene units changed with polymerization conditions but not with monomer composition.
Über den einbau von chlor bei der polymerisation von methacrylsäuremethylester XV. Mitteil. Polymerisationen und polymerisationsinitiatoren
Authors: Bredereck Von Hellmut , Franz Raimund , Krämer Botho
Published: April 2003

Bei der Polymerisation von Methacrylsäuremethylester in Gegenwart von methyleneaktiven Initiatoren sowie Chlorid und Luftsauerstoff wird Chlor in das Polymere eingebaut. Der Einbau wurde radiochemisch bestimmit. Der in Gegenwart von α‐Benzoyl‐propionitril gefundene, von der Chlorid‐Konzentration abhängige Chlor‐Einbau wird durch einen durch Chlorid bewirkten Zerfall des intermediär gebildeten Hydroperoxids gedeutet. In Gegenwart von N‐Äthyl‐bis‐(p‐toluolsulfonylmethyl)‐amin bzw. 1.3.5‐Trimethyl‐barbitursäure ist der Chlor‐Einbau von der Chlorid‐Konzentration unabhängig. Es wird ein bevorzugt thermischer Zerfall des intermediären Hydroperoxids angenommen.
Gemische von polymeren durch cofällung, III. Mitt. Untersuchung der binären polymersysteme: Polyacrylnitril/acetylcellulose, polyvinylacetat/acetylcellulose und polyvinylacetat/polyacrylnitril
Authors: Vasile Von Cornelia , Sandru Florica , Schneider I. A. , Asandei N.
Published: April 2003

Die Änderung der Aktivierungsenergie des thermischen Abbaues von Polymergemischen mit ihrer Zusammensetzung kann zu wertvollen Hinweisen auf die Verträglichkeit oder Unverträglichkeit von Homopolymeren führen. Durch Messung dieser Aktivierungsenergie können sowohl geringe Abweichungen von der Additivitätsregel hervorgehoben und Bereiche maximaler Verträglichkeit abgegrenzt, als auch die thermische Stabilität der gebildeten Pseudolösungen im Vergleich zu den entsprechenden Homopolymeren vorausgesagt werden.

Beim Mischen von pseudoverträglichen Polymeren sind im allgemeinen zwei entgegengesetzte Tendenzen zu beobachten: (a) ein Anwachsen der Aktivierungsenergie infolge von Assoziatbildung und somit ein Anstieg der Thermostabilität, (b) ein Abfall der Aktivierungsenergie infolge Bildung fester Lösungen mit Eutektikum, die durch eine geringere thermische Stabilität charakterisiert sind.

So bestehen bei AcC/PAN‐Cofällungsgemischen negative Abweichungen der Aktivierungsenergie, wobei sich für das Eutektikum ein Wert von ΔE = −14,8 kcal/Mol ergibt. Tatsächlich sinken die Anfangszersetzungstemperaturen der Cofällungsgemische bis zu 25°C unter die entsprechenden Temperaturen bei den Homopolymeren. Dagegen weisen PAN/PVA‐Cofällungsgemische positive Abweichungen auf, wobei sich für ein 1:1‐Gemisch ein Wert von ΔE = 12,3 kcal/Mol ergibt; entsprechend liegt die Anfangszersetzungstemperatur um 15°C höher als die der Homopolymeren.

Bei AcC/PVA‐Gemischen sind keine Abweichungen von der Additivität zu beobachten, was auf das Fehlen von Wechselwirkungskräften hindeutet und somit für Unverträglichkeit dieser Polymergemische spricht.

Es wird versucht, eine strukturelle Erklärung für die beobachteten Erscheinungen zu geben.
Vinyl polymerization 177. Polymerization of acrylonitrile initiated with the imidazole — carbon tetrachloride system
Authors: Imoto Minoru , Takemoto Kiichi , Otsuki Takeki , Ueda Nasuo , Tahara Seiichiro , Azuma Heiichi
Published: April 2003

Acrylonitrile, methyl methacrylate, styrene, methyl acrylate, acrylic acid, and methacrylic acid were found to be polymerized by the system of imidazole and carbon tetrachloride. The polymerization proceeded through radical mechanism. In spite of the presence of carbon tetrachloride, the molecular weight of the polymer obtained was very high. The polymer contained chlorine, and from the reaction product Cl− could be extracted by water. From these results and the data of NMR measurements, an initiation mechanism was proposed. Also some polymers of N‐vinyl compounds, such as poly‐4‐vinylpyridine or poly‐2‐ethyl‐N‐vinylimidazole, were found to be active. However, the initiation mechanism seemed to differ from that by the above imidazole‐carbon tetrachloride system.

In the polymerization initiated by imidazole and carbon tetrachloride, various macromolecules, such as cellulose, poly‐N‐vinylpyrrolidone or poly‐N‐vinylcarbazol, could accelerate the polymerization of acrylonitrile. A matrix mechanism is still in question for this interesting reaction.
A rapid method for the determination of Θ‐conditions of polymer solutions
Authors: Talamini G. , Vidotto G.
Published: April 2003

A method for the rapid determination of the Θ‐conditions of polymer solutions is proposed. According to this method the Θ‐conditions are determined by using an equation, obtained theoretically, which relates the temperature (for binary systems) or composition (for ternary systems) for incipient phase separation, to the molecular weight of the polymer.

The values of the Θ‐conditions obtained using this method are in very good agreement with that determined by other methods.
Copolymerization of vinyl and cyclic monomers in the solid state
Authors: Herz J. H. , Stannett V. , Turner D. T.
Published: April 2003

A study has been made of the polymeric product obtained by exposure to γ‐rays of carefully dried eutectic mixtures of styrene and β‐propiolactone which were sealed in vacuum and maintained at a few degrees below the melting point. No copolymer was formed, only a mixture of homopolymers. However, evidence was obtained which supports an earlier claim that a copolymer is formed by γ‐irradiation of a solid mixture of acrylonitrile and β‐propiolac tone.
The polymerization of acrylamide initiated with ceric ion in the presence of ferric ion
Authors: Narita Hiroshi , Okamoto Susumu , Machida Seishi
Published: April 2003

In the presence of ferric ion, polymerization of acrylamide initiated with ceric ion was studied. The resulting polyacrylamide was found to contain cerium and iron, and the total metal content of the polymer corresponded to one atom per macromolecule. Experimental data of paper electrophoresis, polarography and IR spectroscopy suggested that the metals combined chemically with the polymer molecule. A probable mechanism of introduction of the metal into the polymer chain is discussed.
Application of an absolute X‐ray method for the determination of the crystalline fraction of a series of polymers
Authors: Martuscelli Ezio , Martynov Michael A.
Published: April 2003

An absolute X‐ray method for the determination of the crystalline fraction in polymers based on the comparison of the integrated intensities of some of the low order lines of polymers with those of the completely crystalline standard substances, is described. The crystallinity data are obtained for six polymers: 45.6% for isotactic polypropylene, 73% for polyethylene, 52.1% for nylon‐6, 50.8% for nylon‐66, 32% for isotactic polystyrene, and 33.4% for poly‐4‐methylpentene‐1.

These data are in a reasonable agreement with the data obtained by the other X‐ray procedures. The accuracy of the method, however, is restricted by the general impossibility to know precisely the structure factors and the corrections to the intensities due to the thermal vibrations of the atoms and lattice imperfections.
Graft‐polymerization of styrene on polyethylen single crystals
Authors: Iguchi Masatoshi , Kōyama Yukihiko , Tonami Hiroaki , Kawai Tōru
Published: April 2003

The graft polymerization of styrene through use of γ‐ray irradiation was carried out in vapour phase onto polyethylene single crystals, bulk films of polyethylene and paraffine crystals. It was found that the grafting yield for a given dosage was much less for polyethylene single crystals than for bulk films. The similar difference was also found between the pure paraffine (n‐tetracosane) and mixed paraffines, and these results were interpreted in the light of crystallinity.

In order to characterize the polystyrene branches grafted onto the crystals, a new method based on chain transfer reaction was proposed for obtaining number of the grafted points and the length of the branches and was applied to the graft polymerization onto the polyethylene single crystals.

The results were compared with those obtained for the graft polymerization onto paraffine crystals. In the latter case, molecular weight of the graft polymer obtained after extracting paraffines from the whole material could be obtained by assuming the copolymer as polystyrene homopolymer. In both of the cases the polymer branch was very long and the sites of grafting were very few.

The crystallinities of the samples measured by a X‐ray diffraction method before and after the grafting showed that the grafting did not practically affect the original crystals. The surfaces of the grafted crystals were also examined by an electron microscope and the result implied that the reaction took place mainly on the surfaces of the crystals.
Vinyl polymerization. 186. Polymerization of methyl methacrylate initiated by 9‐anthryldiazomethane
Authors: Nakaya Tadao , Ohashi Koichi , Imoto Minoru
Published: April 2003

A study of the polymerization of methyl methacrylate initiated by 9‐anthryldiazomethane (ADM) has been made. The initial rate of polymerization, Rp, followed the equation:

This equation may be interpreted by the termination reaction of the growing radical with the primary radical. The rate of decomposition of ADM was measured in bulk or in benzene solution and the following rate equation was obtained:
Gelpermeationschromatographie. 1. Mitt. Die trennung oligomerer modellsubstanzen aus diphenylcarbonat und 4.4′‐dihydroxy‐diphenyl‐2.2′‐propan (bisphenol A)
Authors: Sotobayashi Von H. , Lie S. L. , Springer J. , Ueberreiter K.
Published: April 2003

Es wurde versucht, Gemische oligomerer Modellsubstanzen aus Diphenylcarbonat und 4.4′‐Dihydroxy‐diphenyl‐2.2′‐propan (Bisphenol A) mit Hilfe der Gelpermeationschromatographie an Sephadexgelen (LH‐20) zu trennen. Die Messung der Verteilungskoeffizienten (Kd‐Werte) ergab, daß diese bei Substanzen mit phenolischen Endgruppen über den nach dem Molekulargewicht zu erwartenden Werten liegen, woür Adsorptionseffekte am Säulenmaterial verantwortlich gemacht werden. Bisphenol A besitzt einen besonders hohen Verteilungskoeffizienten. Seine Trennun von anderen Substanzen wurde theoretisch und experimentell untersucht. Daraus ergab sich eine neue Methode zur quantitativen Bestimmung, von Bisphenol A.
Some preliminary studies of the photo and photo‐oxidative degradation of polyoxymethylene
Authors: Grassie N. , Roche R. S.
Published: April 2003

Under both 2537 Å and 3650 Å irradiation i. vac. polyoxymethylenes evolve hydrogen and carbon monoxide in a molar ratio of 3.5–4.0. Irradiation in air produces well defined changes in the hydroxyl and carbonyl regions of the infrared spectrum. 2537 Å radiation is approximately 100 times more effective than 3650 Å radiation. Carbonyl absorption has been resolved into three components at 1750, 1785, and 1815 cm−1. Under 3650 Å radiation carbonyl absorption increases autocatalytically while under 2537 Å radiation and equilibrium concentration is quickly achieved. These observations are accounted for qualitatively in terms of current theories of organic oxidation processes.
Synthesis of optically active polymers by asymmetric catalysts. VIII. Asymmetric polyaddition of dimercaptan to dimethacrylate by optically active amine as catalyst
Authors: Inoue Shohei , Ohashi Shin'ichi , Tabata Akira , Tsuruta Teiji
Published: April 2003

Optically active polymers could be obtained by the asymmetric polyaddition of tetramethylene dimercaptan to ethylene dimethacrylate using S‐isobutylethylenimine or its polymer as catalyst. Polymer catalysts showed an enhanced activity in the asymmetric polyaddition.
Conformational studies on oligo‐l‐iso‐butylethyleneurethans. Oligourethan. VII
Authors: Iiwata Kaoru , Iwakura Yoshio , Hayashi Katsumi
Published: April 2003

The conformations of oligo‐l‐iso‐butylethyleneurethans,

(L‐form, n = 1–7), in various solvents were studied by optical rotatory dispersion and infrared spectroscopy.

All oligomers showed simple dispersion in solvents such as alcohols, cyclic ethers, m‐cresol, pyridine, chloroform, and tetrachloroethylene. On the other hand, the hexamer and heptamer showed anomalous dispersions in solvents such as benzene, toluene, and anisol, while lower homologues up to the pentamer showed simple dispersion in these solvents.

The anomalous dispersions were interpreted as a helix

The term “helix” used in this paper for oligourethans means an ordered helical structure, it does not mean an α‐helix of peptides.

formation due to the intramolecular hydrogen bonding.

Small angle X‐ray analysis demonstrated that the observed long spacings of the oigomers agreed well with the calculated chain lengths based on the fully extended models.
Anionic copolymerization of β‐lactones in correlation with the mode of fission. studies on the syntheses of aliphatic polyesters. XI
Authors: Yamashita Yuya , Tsuda Tetsuo , Ishida Hiroyasu , Uchikawa Akihiko , Kuriyama Yasuhisa
Published: April 2003

The copolymerization behavior of β‐propiolactone (PL) and α.α‐bischloromethyl β‐propiolactone (α‐BCPL) is correlated with the mode of fission. With sodium acetate as catalyst, the formation of β‐acetoxy propionic acid at the initiation reaction was observed and α‐BCPL was more than five times as reactive as PL in copolymerization. Thus propagation by carboxylate anion through alkyl‐oxygen fission was presumed in the case of pyridine and the acetate of Na, Li, and Mg as catalyst. On the other hand, the formation of ethyl β‐hydroxy propionate and the decreased reactivity of α‐BCPL in copolymerization was observed with magnesium and aluminum ethoxide as catalyst. In the case of the ethoxide of Na, Li, and Al, and Et2Mg or Et3Al as catalyst, propagation by alkoxide anions through acyl‐oxygen fission of the coordinated lactones was presumed.
Über die synthese polymerer indophenine und deren elektrische eigenschaften
Authors: Kossmehl Von G. , Manecke G.
Published: April 2003

Durch Kondensation von Bis‐{dioxopyrrolino[2′.3′: 1.2; 2″.3″: 5.4]}benzol mit Thiophen sowie durch Reaktion eines Poly[6‐vinylisatin]‐harzes mit Isatin und Thiophen wurden zwei verschiedenartig aufgebaute, Indophenineinheiten enthaltende Polymere synthetisiert, die polymere Küpenfarbstoffe sind.

Das polymere Indophenin I mit einem System konjugierter Doppelbindungen und einem koplanaren Molekülaufbau besitzt bei 25°C und einem Druck von 1500 kp · cm−2 eine spezifische elektrische Leitfähigkeit von σ = 1,1 · 10−4 Ω−1 · cm−1. Die Spinkonzentration beträgt 1,9 1020 spins g−1. Außerdem wurden zum Vergleich die elektrischen Eigenschaften und Spinkonzentrationen von einigen Redoxharzen, die indigoide Farbstoffe bzw. chinoide Strukturen aufweisen, untersucht.
Radiation polymerization of perhydrotriphenylene‐included butadiene
Authors: Löffelholz Marco , Farina Mario , Rossi Umberto
Published: April 2003

The planar isomer of perhydrotriphenylene (PHTP) is a new host molecule for the inclusion polymerization of butadiene. By γ‐irradiation of the PHTP‐monomer adduct an inclusion compound between PHTP and the polymer is obtained, as revealed by its melting point. The recovered polymer has a highly regular trans‐1.4‐structure. The effect of different variables (dose, dose‐rate, PHTP/monomer ratio) has also been studied.
Vinyl polymerization. 202. Polymerization of styrene initiated with the imidazole/carbon tetrachloride system: A kinetic study
Authors: Imoto Minoru , Takemoto Kiichi , Azuma Heiichi
Published: April 2003

The polymerization of styrene initiated with the imidazole/carbon tetrachloride system was studied kinetically in a benzene/acetone solution at 85°C. It was found that the rate of polymerization could be expressed by the following equation:

From the results the initiation mechanism was discussed.
Polymerization of cyclic acetals. Cationic polymerization of 2‐vinyl‐4.5‐dimethyl‐1.3‐dioxolane
Authors: Jedliński Z. , Łukaszczyk J.
Published: April 2003

The cationic polymerization of 2‐vinyl‐4.5‐dimethyl‐1.3‐dioxolane (VDMD) with BF3·Et2O, SnCl4, TiCl4, and various cocatalysts was investigated, and probable reaction mechanisms were proposed. Linear oily products of low molecular weight have been obtained. In contrast, the unsubstituted 2‐vinyl‐1.3‐dioxolane forms cross‐linked polymers. Methylene substituents in positions 4 and 5 in acetal rings make it less reactive. Crosslinked polymers from VDMD were also obtained, when epichlorohydrine was used as cocatalyst. These cross‐linked products contain halogen. This shows the possibility of copolymerization of epichlorohydrine and VDMD beside a cocatalytic effect.
Versuche zur herstellung eines makroporösen polymethacrylat‐gels
Authors: Determann Helmut , Kriewen Manfred , Wieland Theodor
Published: April 2003

Durch Copolymerisation von Methacrylsäuremethylester und Äthylenglykoldimeth acrylsäureester in Gegenwart verschiedener, nachträlich entfernbarer Füllstoffe (Polystyrol, Glukose, Calciumcarbonat and Natriumcarbonat) wurden Gele erhalten, die nach Zerkleinerung auf ihr chromatographisches Trennvermögen für Makromoleküle in Tetrahydrofuran geprüft warden. Die Gele zeigen im Bereich hoher Molekulargewichte eine gewisse Trenniwirkung.
Catalytic effects of poly(acrylhydroxamic acid)‐copper chelates on decomposition reaction of hydrogen peroxide
Authors: Hatano Masahiro , Nozawa Tsunenori , Yamamoto Takakazu , Kmbara Shu
Published: April 2003

Decomposition reaction of hydrogen peroxide was effected under various conditions by using poly(acrylhydroxamic acid)‐copper chelates as catalysts. The catalytic effect of these chelates is discussed on the basis of kinetic data concerning, with chelate formation from the polymeric ligands (L). The initial rate of the decomposition reaction which depended upon the initial concentration of hydrogen peroxide, increased with the ratio of total concentration of cupric ion to total concentration of the ligand group (TCu/THL). The relation between initial rate and the initial concentration of hydrogen peroxide varied in accordance with the rate expression of MICHAELIS‐MENTEN type. These experimental results are discussed on the basis of values of chelate formation constants obtained in the preceding paper. Thus, the chemical species which contribute to the catalytic activity were assumed to be CuL+, e.i., the chemical species derived from a cupric ion and one hydroxamic group. So, an addition of this ligand in excess with respect to formation of CuL+ caused competitive inhibition for the decomposition reaction of hydrogen peroxide.
Über Derivate des Poly‐α‐chloracroleins. II. Dehydrochlorierung von Poly(α‐chloracroleindimethylacetal‐co‐vinylchlorid) und Poly‐α‐chloracroleindiacetat mit Basen
Authors: Lengweiler Von Willi
Published: April 2003

Die Dehydrochlorierung des Poly(vinylchlorid‐co‐α‐chloracroleindimthylacetals) mit Natriumamid in Ammoniak oder Tetrahydrofuran führt schon bei einem Chlorgehalt unterhalb 36,5% zu unlöslichen Produkten. Mit Kalium‐tert‐butylat waren die Dehydrochlorierungsprodukte dagegen noch his zu einem Gehalt von ca. 10% Chlor löslich. Die Delhydroclorierungsgeschwindigkeit ist beim Kalium‐tert‐butylat praktisch unabhüngig von der Copolymerzusammensetzung. Bei hohen Basenkonzentrationen und kleinen Dehydrochlorierungsgraden hängt die Geschwindigkeit nur von der Chlorkonzentration ab, bei hohen Dehydrochlorierungsgraden dagegen nur noch von der Basenkonzentration. Für diese Grenzfälle wurden die ungewöhnlichen Exponenten von 3,3 Für die Chlorkonzentration bzw. 4,3 Für die Basenkonzentration gefunden. Das Heptaen weist unterhalb eines Chlorgehaltes von etwa 34% immer das höchste Absorptionsmaximum auf, wenn von einem Copolymeren mit 74 Mol‐% Vinylchlorid ausgegangen wird. Die Reaktionstemperatur hat keinen Einfluß auf die Sequenzverteilung der konjugierten Doppelbindungen. Dien‐ und Trien‐Sequenzen sind bei allen Reaktionszeiten am häufigsten vorhanden.
Anionic copolymerization of ω‐lactams with ω‐lactones
Authors: Komoto Hiroshi
Published: April 2003

Copolymerizations of ε‐caprolactam, α‐pyrrolidone or α‐piperidone with ε‐caprolactone or δ‐valerolactone have been carried out in the presence of alkali metal. It has been shown that in copolymerizations of ε‐caprolactam or α‐pyrrolidone with ε‐caprolactone and α‐pyrrolidone with δ‐valerolactone conversions of above 70 % and reduced viscosities of above 0.5 in m‐cresol at 35°C for all compositions were obtained. In the case of copolymerization of ε‐caprolactam with δ‐valerolactone at 180°C a conversion of 25 % and a reduced viscosity of 0.5 were obtained, but the polymer was polycaproamide, while at 90°C the conversion was 50 % but the polymer was polyvalerolactone. In copolymerizations of α‐piperidone with ε‐caprolactone or δ‐valerolactone the copolymer contained only polyester.

A mechanism is proposed for the copolymerization of ω‐lactams with ω‐lactones with alkali metal, which involves chain propagation by the stepwise addition of the lactam ring at an end of the chain molecule and by the stepwise addition of the lactone ring at the other end of the chain molecule, resulting to a certain extent in the formation of polyester and polyamide segments.

This mechanism is supported by experimental results obtained through the reaction in the presence of alkali metal salts of ω‐lactam, data on infrared analyses and elementary analyses, and by experimental results obtained through measurements of physical properties of these copolymers.
The butyllithium initiated bulk anionic polymerization of α‐methylstyrene
Authors: Wyman D. P. , Song I. H.
Published: April 2003

Butyllithium (BuLi) initiates α‐methylstyrene polymerization in bulk at room temperature. Both initiation and propagation reactions are very slow and propagation/depropagation occurs along with other side reactions, e.g., transfer. At slightly elevated temperatures (40–50°C) irreversible termination takes place. Molecular weights change inversely but not linearly with changes in [BuLi] and distributions are broad (M̄w/M̄n = 1.55 to 2.2) as would be expected from equilibria considerations. These results are generally different than those reported with sodium initiated reactions.
Studies on organometallic compounds as polymerization catalysts. II. Diethylzinc/water system for epoxide polymerization
Authors: Ishimori Michihiro , Nakasugi Osami , Takeda Nobuyuki , Tsuruta Teiji
Published: April 2003

Diethylzinc/water system was studied using infrared spectroscopy, X‐ray diffraction, and vapor phase chromatography. The main reactions of diethylzinc with water are considered to be as follows:

Relative LEWIS acidity for ether is found to be in the order:

Initiators for the polymerization of propylene oxide by diethylzinc/water system are found to be Et(ZnO)nZnEt, Et(ZnO)nH, or HO(ZnO)nH, which have disordered wurtzite structures concerning zinc‐oxygen bond. On the hydrolysis of the polymerization system, 2‐methyl‐l‐butanol, 2‐pentanol, and propylene glycol are found as initial products. The main reaction of the polymerization of propylene oxide catalyzed by diethylzinc/water system was discussed in terms of the coordinate ionic mechanism.
Copolymere von Vinylhalogeniden mit Olefinen. 1. Qualitative IR‐spektroskopische Untersuchungen an Vinylchlorid‐Propen‐Copolymeren
Authors: Pohl Von H. U. , Denaxas J. , Hummel D. O.
Published: April 2003

Zwei Reihen von Vinylchlorid‐Propen‐Copolymeren, strahlenchemisch polymerisiert bei −63 und +23°C, wurden im Bereich von 5000 bis 400 cm−1 IR‐spektroskopisch untersucht. Die Zuordnung der Banden zu den einzelnen Strukturen basiert auf ihrer Intensitätsänderung mit zunehmender Polymerisations‐ und Meßtemperatur sowie steigendem Propengehalt der Proben. Die Spektren ermöglichen Aussagen über die Struktur der Copolymerenketten.
Copolymere von Vinylhalogeniden mit Olefinen. 2. Quantitative IR‐spektroskopische Untersuchungen an Vinylchlorid. Propen‐Copolymeren
Authors: Pohl Von H. U. , Hummel D. O.
Published: April 2003

Die überlagerten ν(CCl)‐Schwingungen im Bereich von 600 bis 700 cm−1 sowie die δ(CH3)‐ und δ(CH2)‐Schwingungen zwischen 1370 und 1470 cm−1 wurden in Einzelbanden aufgetrennt. Die Halbwertsbreiten und relativen integralen Extinktionen dieser Banden wurden in Abhängigkeit von der Zusammensetzung an zwei Copolymerenreihen der Polymerisationstemperatur +23°C und −63°C bestimmt. Verschiedene Möglichkeiten einer IR‐spektroskopischen Ermittlung der Zusammensetzung von Vinylchlorid‐Propen‐Copolymeren wurden untersucht.
Synthesis and conformational studies of oligo‐1‐iso‐propylethyleneurethans. Oligourethans. VIII.
Authors: Iwata Kaoru , Iwakura Yoshio , Hayashi Katsumi
Published: April 2003

Oligo‐1‐iso‐propylethyleneurethans with one to four repeating units,

were synthesized by a stepwise method. Their conformational aspects in solution were investigated by optical rotatory dispersion, infrared spectroscopy, and nuclear magnetic resonance.

It was concluded that the monomer through trimer exist as random coils in all solvents tried while the tetramer forms a helical structure in such solvents as ethanol, benzene, toluene, and xylene. Dioxane and chloroform were random‐coil solvents for the tetramer. The helical structure was destroyed by the addition of a random‐coil solvent or by elevating temperature.

The intramolecular hydrogen bonding between NH and CO was demonstrated to participate in the helix

The term „helix”︁ used in this paper for oligourethans means an ordered helical structure and does not necessarily mean the α‐helix of peptides.

formation.
Ternary polymerization catalyst consisting of group ii metal halide, triethylaluminum and carbon tetrachloride
Authors: Saito Kazuo , Saegusa Takeo
Published: April 2003

The present paper describes the ternary catalyst system consisting of Group II metal halides, AlEt3, and CCl4, which initiatesatroom temperature the polymerizations of ethylene (60 atmospheres), styrene, vinyl acetate, methyl methacrylate, acrylonitrile, and isobutyl vinyl ether. As the component of Group II metal halide, ZnCl2, ZnI2, CdCl2, MgCl2, and BeCl2 were effective. This catalyst system induced the cationic polymerization of vinyl ether. On the other hand, the copolymer composition curve of the styrene‐methacrylate copolymerization with this catalyst system was close to that of free radical copolymerization. In addition, this catalyst system has also been characterized by the 1:1 alternating copolymerization of ethylene with vinyl acetate at room temperature.
Comparative studies of the solution properties of vinyl aromatic polymers
Authors: Utracki Lechoslaw A. , Simha Robert
Published: April 2003

Viscosity and NMR studies of poly‐1‐vinylnaphthalene, (PIVN), poly‐2‐vinylnaphthalene, (P2VN), and poly‐vinylbiphenyl, (PVB) solutions were carried out over a range of temperatures and molecular weights. For these polymers as well as polystyrene the viscosities at finite concentrations indicate two transition regions at about 20 and 50°C. At infinite dilution no transitions were observable except for P2VN, where a transition region around 45°C was noted. From the temperature and molecular weight dependence of [η], the conformational parameter σ = (〈r〉/〈r〉)1/2, interaction parameter B and their temperature dependence are obtained. For P1VN and P2VN, dσ/dT < 0, whereas the opposite holds for PVB. At 30°C, σ is a linear function of the volume of the pendant group. The transition observed by viscosity and NMR is not reflected in B. For P2VN and PVB dB/dT < 0. For P1VN which was found to be partially crystalline, dB/dT > 0. From the NMR studies of P2VN solutions the activation energy of the main transition at 50° is calculated as E = 23 ± 4 kcal/mole for 100% polymer, indicating strong hindrance of motions. The transition has been ascribed to motions of the backbone chain.
The bulk and suspension polymerization of vinyl chloride
Authors: Crosato‐Arnaldi A. , Gasparini P. , Talamini G.
Published: April 2003

The bulk and suspension polymerization of vinyl chloride are studied.

The comparison between the two processes demonstrates that they are kinetically equivalent.

It is found that an equation recently suggested to describe the bulk polymerization of vinyl chloride agrees quite well with the experimental data.
Ionic polymerization under an electric field. XI. Field effect and catalyst strength
Authors: Ise Norio , Hayashi Yuzuru , Chen Shou‐Xyng , Sakurada Ichiro
Published: April 2003

The influence of an electric field on homopolymerizations and copolymerizations of styrene catalyzed by stannic chloride/trichloroacetic acid (SnCl4/TCA) or titanium tetrachloride‐trichloroacetic acid (TiCl4/TCA) in binary mixtures of toluene and 1.2‐dichloroethane was investigated. The field enhancement in the homopolymerization increased with increasing dielectric constant of solvent, and, passing through a maximum value, decreased with further increase in the dielectric constant. The value of the dielectric constant, at which the field effect showed a maximum value, increased with catalyst in the order: TiCl4/TCA < SnCl4/TCA < boron trifluoride etherate (BF3OEt2). This order was the same as that for the field effect on the rate of homopolymerization in pure 1.2‐dichloroethane. The reactivity of styrene in the copolymerization of styrene and indene in pure 1.2‐dichloroethane increased in the order: BF3OEt2 < SnCl4/TCA < TiCl4/TCA. The electric field increased the reactivity of styrene in the copolymerization in the order: TiCl4/TCA < SnCl4/TCA < BF3OEt2. It was concluded from the observed sequence, on the basis of the mechanism proposed previously, that the catalyst strength for the Styrene polymerization increases in the order: BF3OEt2 < SnCl4/TCA < TiCl4/TCA. This sequence was in agreement with that reported earlier.
6‐O‐methacryloyl‐D‐galactose: A reactive, water‐soluble monomer
Authors: Black W. A. P. , Colquhoun J. A. , Dewar E. T.
Published: April 2003

Deacetonation of the crystalline monomer, 1.2:3.4‐di‐O‐isopropylidene‐6‐O‐methacryloyl‐α‐D‐galactopyranose(DGM, I) in 80% formic acid solution at 20°C gave the syrupy, water‐soluble monomer 6‐O‐methacryloyl‐α‐D‐galactopyranose (α‐GM) was a white crystalline compound which showed characteristic infrared absorption. The NMR spectrum of α‐GM in deuterium oxide was complicated by two variable: (i) mutarotation and (ii) gradual polymerisation. Syrupy GM was polymerised with ammonium persulphate to a water‐insoluble, cross‐linked hydrogel.
Thermal degradation of polyacetaldehyde having polyvinylalcohol‐type structure
Authors: Matsubara Tsutomu , Imoto Tatsuya
Published: April 2003

It was reported that an acetaldehyde polymer (PACH) having the polyvinylalcohol type structure was obtained by polymerization of acetaldehyde with alkali metal amalgam as catalyst. The thermal degradation of this polymer was carried out at 81.5, 110.8, 136.5, 170.0, 2104.0, and 219.5°C by thermogravimetric analysis. The two samples studied had molecular weights of 487 and 530 resp. At an early stage the rate of thermal degradation is of the first order with respect to polymer concentration. At a later stage, the degradation rate is not first order, because of some side‐reactions. At 219.5°C, the thermal degradation rates are 9.5·10−2%/sec. (Mol. wt. = 530), and 1.3·10−1%/sec. (Mol. wt. = 487). Activation energy is 13 kcal/mole for both polymers.
The mean activity coefficient of polystyrenesulphonic acid
Authors: Dolar D. , Leskovšek H.
Published: April 2003

The electromotive force of the concentration cell (Pt) H2/polystyrenesulphonic acid polystyrenesulphonic acid/H2 (Pt) with liquid‐liquid junction was measured in the concentration range of the polystyrenesulphonic acid from 0.1 to 0.001 monomolal. The values of the mean activity coefficient, derived from these measurements, were compared with those calculated on the basis of the rodlike model. A very good agreement between theory and Zxperiment has been found.
Polymer deformation. XIII. Deformation of thin films of polyoxymethylene
Authors: O'Leary K. , Geil P. H.
Published: April 2003

The deformation of four types of thin films of polyoxymethylene is discussed. Failure, even at elevated temperatures, occurred by micronecking or in a brittle manner. Slip bands were observed in some of the samples. Moiré patterns from portions of the sample indicated little internal distortion of the lamellae during the brittle failure. Micronecking with fibril formation occurred primarily during draw at temperatures near the α transition temperature. The results are in general agreement with concepts of the deformation process previously developed on the basis of work with thin films of polyethylene but cannot be applied directly to the mechanism of deformation of bulk samples.