bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of unsaturation in cyclized rubber using phenyl iododichloride
Authors: Rao N. V. C. 
Published: April 2003

AbstractUnsaturation in cyclized rubber was estimated using phenyliododiochloride and the values obtained are in close agreement with the theoretical values predicated by Flory and Gordon. They are significantly different from those obtained by Van Veersen using hydrogen chloride, earlier described in the literature. This new method for determination unsaturation is simple and gives accurate results.
Light scattering and viscosity studies on some branched starch polymers
Authors: Stacy Carl J. , Foster Joseph F. , Erlander Stig N. 
Published: April 2003

AbstractPreliminary studies are reported regarding the molecular weight of amylopectins and limit dextrins from various sources, using the light scattering method. Apparent molecular weights of all samples are in the millions, and centrifugation studies conclusively demonstrate that the high value determined by light scattering is not due to the presence of relatively insignificant percentages of undispersed material of much larger particle weight. One normal KOH was used as solvent. Since the possibility of air‐alkaline degradation exists using this solvent, some studies designed to determine the importance of this factor are reported. It was found that if air was excluded the particle weights remained in the millions for as long as 54 days, during which time the samples were degraded to less than one hundredth the original weight if air or pure oxygen were present. Further experiments demonstrated that the dispersions were stable during the time necessary for light scattering runs.Intrinsic viscosity data on the amylopectins and their limit dextrins are reported. The intrinsic viscosity of a given amylopectin and the derived limit dextrin are very similar, and in general it is found that there is a very low positive dependence of intrinsic viscosity upon molecular weight for these materials, a result to be expected on the basis of the extensive branching.
Studies on the polymerization of bifunctional monomers. XI. The cyclic polymerization of divinyl ether and the structure of the polymer
Authors: Aso Chuji , Ushio Sunao , Sogabe Masateru 
Published: April 2003

AbstractThe radical polymerization of divinyl ether was further studied. In order to clarify the cyclic structure of poly (divinyl ether), the saponification and the oxidation of the polymer were studied.While the conversion of the polymer to poly (vinyl acetate) was tried without sucess, about 1% of succinic acid was obtained by oxidation with nitric acid. This indicates the presence of head‐to‐head bonds in the polymer. Moreover, a bicyclic telomer composed of two moles of monomer and one mole of chloroform was obtained by the telomerization of divinyl ether in chloroform. The IR‐ and NMR‐spectra indicated the presence of a methyl group in that telomer. From these results, a structure containing bicyclic rings is sugessted for poly (divinyl ether) which was obtained by solution polymerization in benzene. This bicyclic ring is considered to have partly tail‐to‐tail addition and at least one five‐membered ring.
Chain transfer to ethers in the 3,3‐bis(chloromethyl)oxetane polymerization catalyzed by Al(iso‐C4H9)3
Authors: Penczek Irena , Sazanov Yurǐ N. , Penczek Stanislaw 
Published: April 2003

AbstractIn the polymerization of 3,3‐bis(chloromethyl)oxetane catalyzed by Aliso‐C4H9/water catalyst, according to the previously reported data (FURUKAWA, SAEGUSA et al.) insoluble polymers are formed. Although neither the exact mechanism of oxetanes polymerization in the presence of AIR3/H2O catalysts nor the nature of the insoluble polymers are known it is possible to use chain transfer agents to obtain perfectly soluble polymers. The addition of low molecular weight ethers (C2H5)2O, (n‐C4H9)2O, (Allyl)2O, 1,4‐dioxane, (β‐ClC2H4)2O, CH3OPh, and (C6H5)2O in low concentrations leads to the formation of soluble polymers with a very large range of mol. wts. (up to 106). The chain transferabilities of ethers increase with their proton‐attracting powers (basicity). In the presence of a chain transfer agent the kinetics of polymerization virtually changes. On the basis of the discussion of the general kinetic behaviors of the system and the dependence of D̄P̄ on conversion it was deduced that in this type of polymerization long living species are formed.
Syntheses of some polymers containing cyclopropane rings in the main chain. III
Authors: Oku Akira , Shono Tatsuya , Oda Ryohei 
Published: April 2003

AbstractSome poly (5‐iminohydantoins) containing a cyclopropane ring in the main chain were synthesized from trans‐1,2‐cyclopropane diisocyanate (trans IC) and trans‐1,2‐cyclopropane diacylisocyanate (trans AIC). For example, the polymer obtained from methylene bis‐(4‐phenyl isocyanate) and trans‐1,2‐cyclopropane di(carbamoyl cyanide) prepared from trans IC showed an intrinsic viscosity of [η] = 0.45. Furthermore, the cyclic polymerization of cis‐1,2‐cyclopropane diisocyanate was studied; the highest intrinsic viscosity of the cyclic polymer was 0.11.
Beiträge zur lösungsviskosität. I. Über zusammenhänge zwischen kH (HUGGINS) und dem ausdehnungs‐koeffizienten αη und zwischen den verschieden definierten grenzviskositätszahlen [η]Θ, [η]T und [η]R untereinander
Authors: Berger Von Ralf 
Published: April 2003

AbstractAn Hand von Ergebnissen aus der Literatur und darauf aufbauenden Überlegungen wird eine Beziehung zwischen kH (HUGGINS) und αη (FLORY):

und eine zwischen verschieden definierten und verschieden bestimmbaren Grenzviskositätszahlen [η]Θ, [η]T und [η]R:

angegeben. Eine mögliche Anwendung dxieser letzten Beziehung zur Berechnung der realen Knäueldichte im Θ‐Zustand wird kurz diskutiert.
The role of various inorganic solid additives in radiation‐induced solid state polymerization of 3,3‐bis‐chloromethyloxetane
Authors: Kagiya Tsutomu , Izu Masatsugu , Fukui Kenichi 
Published: April 2003

AbstractThe effects of solid additives on the radiation‐induced polymerization of 3,3‐bis‐(chloromethyl) oxetane were studied. Some of the additives which acelerate the polymerization rate of the unpurified monomer, showed no effect with the purified monomer. The results obtained with the pure monomer, showed, that (1) the number of polymer chains under the same conditions was independent of the kind of solid additive, and was constant; (2) the rate of polymerization and the intrinsic viscosity of the polymer increased with irradiation time. From these results, it was concluded that the role of the additive was to depress a termination reaction by trapping the poison for polymerization.
Some remarks on the origin of weak chemiluminescence during polymer oxidation
Authors: Reich Leo , Stivala S. S. 
Published: April 2003

AbstractVarious kinetic expressions for the autoxidation of relatively simple hydrocarbons, based on chemiluminescence studies, were obtained by Russian workers. They assumed that the emitted light intensity, I, was a function of RO2•2 in order to explain their experimental data. This paper purports to show that much of their kinetic data can also be explained by assuming that I is a function of [RO2H].
Reaction modes and polymerization of crotonic esters with lithium aluminum hydride
Authors: Tsuruta T. , Makimoto T. , Miyazako T. 
Published: April 2003

AbstractThe reaction products of lithium aluminum hydride with crotonic esters under polymerization conditions were analyzed by gas chromatography. The ratios of carbon‐carbon double bond‐ to carbonyl‐addition of the hydride ion toward methyl, iso‐propyl, iso‐butyl and sec‐butyl crotonates are determined as 3:1, 20:1, 9:1, and 40:1, respectively. The intermediate double bond addition product was confirmed to be a precursor of the polymerization. The precursors undergo successive carbonyl‐addition onto monomer, terminating the propagation rapidly in the reactions with methyl and isobutyl esters; in case of iso‐propyl and sec‐butyl esters double bond additions yielded high polymers. The reaction product of methyl crotonate and lithium aluminum hydride showed good catalytic activity for polymerization of crotonates.
Catalyst behavior of aluminum alkyl systems in the polymerization of cyclic ethers
Authors: Saegusa Takeo , Ueshima Takashi , Tomita Shimpet 
Published: April 2003

AbstractThe polymerization of cyclic ethers, especially of epichlorohydrin, by AlEt3 and AlEt3/H2O system was studied. From the effects of solvent (CH2Cl2) and of a small amount of pyridine upon the copolymerization of epichlorohydrin with tetrahydrofuran, it has been assumed that there are at least two active species in these polymerizations: one is responsible for cationic polymerization and the other is for coordinate anionic polymerization. This assumption has been supported by the stoichiometric reactions of these catalysts with epichlorohydrin and also by the behavior of the alkoxide modified systems of AlEt3 and AlEt3/H2O.
Vinyl polymerization. 170. Grafting of some acrylates and methacrylates onto cellulose and silk in absence of radical initiators
Authors: Imoto Minoru , Takemoto Kiichi , Azuma Hei‐ichi , Kita Nobuyuki , Kondo Mitsuru 
Published: April 2003

AbstractThe polymerization and copolymerization of various acrylates and methacrylates in presence of cellulose or silk and water were studied without radical initiators. The polymerization of methacrylates proceeded more easily than that of acrylates, and in general the grafting was much higher onto silk than cellulose. It was also found that methyl methacrylate could be grafted onto OH‐group containing synthetic copolymers. Both optical and electron microscopic observations were made on the methyl methacrylate‐grafted silks.
Base‐catalyzed polymerization of sorbamide and β‐vinylacrylamide
Authors: Tsunetsugu T. , Matsuo T. , Furukawa J. 
Published: April 2003

AbstractSorbamide and β‐vinylacrylamide were polymerized using tert‐BuONa and n‐BuLi as catalysts. The resulting polymers were analysed by infrared spectroscopy and hydrolyzed to subject to paper chromatography. The hydrolysis products were primarily δ‐amino acids. Thus it was concluded that the polymerization proceeded mainly by the hydrogen transfer mechanism, leading to poly‐δ‐amides.Poly‐β‐vinylacrylamides obtained by basic catalysts were insoluble, whereas polysorbamides were soluble at first but became insoluble on standing under air. Both these polyamides were amorphous.
Synthèse de nouvelles N‐glycidylamides cycliques. 14ième communication sur la chimie des résines époxydes1
Authors: Porret Par D. 
Published: April 2003

AbstractLa synthèse de nouvelles N‐glycidylamides cycliques est décrite et le mécanisme de la réaction est discuté. Certaines des nouvelles combinaisons sont bien solubles dans l'eau et permetient ainsi de nouvelles applications dans le domaine des résines époxydes. Celles qui sont peu solubles, durcies avec des anhydrides d'acides ou des amines, donnent des résines présentant de bonnes propriétés mécaniques et électriques.
The thermal degradation of poly(methyl acrylate). Part II. The mechanism of chain breaking
Authors: Cameron G. G. , Kane D. R. 
Published: April 2003

AbstractThe rate curves for the conversion of poly(methyl acrylate) to volatiles at 286–310°C show maxima in the region 10–20% conversion, consistent with random degradation with transfer. The molecular weight changes in the early stages of the reaction also suggest random breakdown. A reaction mechanism involving initiation by random homolytic back‐bone bond scission followed by a chain of free radical transfer reactions, inter‐ and intramolecular, is proposed. Chain‐end initiation appears to be unlikely. The free radical inhibitor 1.4‐diaminoanthraquinone was found to retard both volatile formation and random chain scission thus supporting the proposed mechanism. The energies of activation for volatile formation and random chain scission are 35 and 33 kcal/mole respectively.
Cross‐Linking efficiency of styrene‐butadiene rubber with dicumyl peroxide and evaluation of interaction parameter
Authors: Bhatnagar S. K. , Banerjee S. 
Published: April 2003

AbstractThe cross‐linking efficiency of dicumyl peroxide with styrene‐butadiene rubber (SBR‐1507) has been measured by the swelling method. The values are found to be 2.5 and 5.0 for unpurified and purified SBR, respectively. The lower value in the former case has been ascribed to the destruction of peroxy radicals by the antioxidants present in the rubber. The physical cross‐links due to chain entanglement for purified SBR are found to be 0.14 . 10−4 mole/g of rubber (0–07.10−4 cross‐links due to chain entanglement/g of rubber). The solubility parameter for purified SBR as determined from both swelling and viscosity measurements is found to be 8.45 (kcal/ml)1/2 or cohesive energy density as 71.403 kcal/ml. Using this value of the solubility parameter, the solvent‐polymer interaction parameter is calculated and is further verified by HUMMEL'S method. The average value is found to be 0.37.
Polycondensation‐addition. VI. Optically active polyurethan‐ureas
Authors: Lwakura Yoshio , Hayashi Katsumi , Inagaki Koichi 
Published: April 2003

AbstractHigh molecular weight of optically active polyurethan‐ureas were prepared from optically active 2‐alkyl‐2‐isocyanatoethyl chloroformates and optically active diamines by interfacial polycondensation‐addition.No dramatic differences in solid properties such as polymer melt temperature and crystallinity were observed between the optically active polyurethan‐ureas and the corresponding racemic polymers. The optical rotatory dispersions of the polymers in various solvents simply obeyed the one‐term DRUDE equation.
Polymerization of methyl isopropenyl ketone and coloration of the polymers
Authors: Matsuzaki Kei , Lay Ting Che 
Published: April 2003

AbstractIsopropenyl methyl ketone was polymerized with γ‐ray radiation and with phenylmagnesium iodide in toluene. The polymers obtained with phenylmagnesium iodide as catalyst were separated into methyl ethyl ketone‐soluble and ‐insoluble parts. The soluble parts were amorphoas, while the insoluble parts were crystalline.Treatment of the polymers by heat, alkali and chlorinated solvents induced aldol condensation. It was confirmed by infrared and ultraviolet spectrometry that the crystalline polymer underwent aldol condensation between adjacent units more easily than the amorphous polymer at temperatures lower than 180°C, forming monocyclic structures predominantly, whereas the amorphous polymer resisted in the earlier stage of heating but was more rapidly degraded between 180‐260°C than the crystalline polymer. The length of the conjugated double bond sequences produced in the amorphous polymer showed random distribution.
Copolymerization of cyclic ethers with vinyl compounds. II. Effects of copolymerization conditions on cationic copolymerization of epichlorohydrin with styrene
Authors: Mitoh Motonori , Minoura Yuji 
Published: April 2003

AbstractCationic copolymerization of epichlorohydrin with styrene was carried out under various conditions. The copolymer obtained was fractionated into two fractions: one was a methanol‐soluble liquid, and the other was a methanol‐insoluble solid polymer. The liquid polymer was found to be very rich in epichlorohydrin and the solid one was on the contrary very rich in styrene. The effects of catalysts, catalyst concentration, polymerization temperature and some other conditions on the copolymerization were investigated.
High resolution NMR studies on sequence distribution of vinylidene chloride copolymers
Authors: Ito Koichi , Iwase Seigo , Yamashita Yuya 
Published: April 2003

AbstractSequence distributions of several radical copolymers of vinylidene chloride were examined by NMR spectroscopy, including methyl methacrylate, benzyl methacrylate, methaeryloyl chloride, methyl acrylate, α‐methylstyrene, styrene, and vinyl acetate as comonomers. Except for the α‐methylstyrene and styrene systems, some of the diad, triad, and tetrad sequences were observed in the CH2 and αCH3 resonances and are discussed in the light of the usual copolymerization theory.
Polymerization of vinyl acetate under high pressure
Authors: Nakamoto Hideo , Ogo Yoshiaki , Imoto Tatsuya 
Published: April 2003

AbstractHigh pressure radical polymerization of vinylacetate with and without solvents has been investigated in the range of 1–2000 kg/cm2.The pressure has the ability to interrupt an occurrence of branching in bulk polymerization and the overall chain length of polyvinylacetate increases with pressure.In solution polymerization, the magnitude of the activation volume of chain transfer to solvent is in following order: toluene > chlorobenzene > bromobenzene. In both cases, the overall rates of polymerizations and the molecular weights of polymers obtained increased with increasing pressure.The overall activation volumes of vinylacetate polymerization are −17.4 ml/mole without solvent and −12.0 ml/mole in benzene.
Initiation of polymerization by sulphur dioxide and pyridine in the presence of organic halides
Authors: Bamford C. H. , Reynolds R. J. W. , Seddon J. D. 
Published: April 2003

AbstractThe initiation of the polymerizations of methyl methacrylate and styrene by sulphur dioxide + pyridine in the presence of organic halides has been studied. The kinetics are consistent with free‐radical reactions and indicate the occurrence of a rate‐determining step not involving the halide, forming an intermediate which yields radicals on reaction with the halide.When polyvinyl trichloracetate (PVTCA) is the halide gelation occurs, showing that the primary radicals are attached to the PVTCA chain, and suggesting that radical formation involves removal of a halogen atom from the halide molecule.This initiating system shows resemblances to those composed of a derivative of a zerovalent metal in association with an organic halide.
Catalytic activity of some chelate polymers derived from cupric ion and polymeric ligands having hydroxamic acid groups
Authors: Nozawa Tsunenori , Nose Yoshinori , Hatano Masahiro , Kambara Shu 
Published: April 2003

AbstractThe following chelate‐polymers were synthesized and their catalytic activity was investigated:

These chelate‐polymers were found to catalyse the decomposition of hydrogen peroxide. For purposes of comparison, the copper‐chelate of methyl hydroxamic acid (IV) also was synthesized; it showed no catalytic effect. The chelates (I) and (II), on the other hand, were found to have large catalytic activity for the decomposition reaction of hydrogen peroxide in aqueous solution, while their polymeric ligands alone exhibited no catalytic activity for this reaction, or, at least, less activity than the chelates themselves. In the case of the chelate (II), it was found that the catalytic activity depends on the molecular weight of the polymeric ligand.On the basis of structural analyses by means of visible and infra‐red spectroscopy, the catalytic activity of these chelate polymers is assumed to depend on the bond strength between the ligand and the copper ion.
Pfropfcopolymerisationen mit makromolekularen polyradikalanionen und polyanionen
Authors: Braun Von Dietrich , Neumann Werner , Arcache Gilbert 
Published: April 2003

AbstractAus Copolymeren aus p‐Vinylbenzophenon, aus p‐Vinylbenzophenonanil und aus p‐Vinyl‐p′‐dimethylaminoazobenzol und Styrol entstehen mit Natrium in Tetrahydrofuran Lösungen der entsprechenden Polyradikalanionen und Polydianionen. Die makromolekularen Radikalanionen der beiden erstgenannten Copolymeren starten die Pfropfcopolymerisation von Acrylnitril und Methylmethacrylat, die entsprechenden Polydianionen darüber hinaus auch die Pfropfcopolymerisation von Styrol; mit Styrol entstehen dabei „lebende”︁ Seitenzweige. Vom Mononatriumaddukt des Copolymeren aus p‐Vinyl‐p′‐dimethylaminoazobenzol und Styrol wird nur Acrylnitril polymerisiert; die entsprechende Dinatriumverbindung bringt neben Acrylnitril noch Methylmethacrylat zur Pfropfcopolymerisation, aber nicht Styrol. Durch Lösungsversuche läßt sich zeigen, daß in den Pfropfprodukten mit Acrylnitril und Methylmethacrylat praktisch keine ungepfropften Rückgratpolymeren und keien Homopolymeren enthalten sind.
Polymerization of propylene to syndiotactic polymer. III. Behaviour of the catalyst system VCl4‐Al(C2H5)2Cl in the presence of lewis bases
Authors: Zambelli A. , Pasquon I. , Signorini R. , Natta G. 
Published: April 2003

AbstractPolymerizations of propylene to syndiotactic polymer have been carried out in the presence of the catalyst system VCl4‐Al(C2H5)2Cl‐anisole. The data obtained have been related to those previously reported concerning the catalyst system, VCl4‐Al(C2H5)2Cl. It was thus possible to propose a mechanism of formation of the catalytic complexes and to put forward or confirm some hypotheses on their constitution.A polymerization mechanism is also proposed that can justify both the type of stereoregularity of the polymer and the variation of steric regularity on varying the polymerization conditions.
Zur anionischen copolymerisation von α‐methylstyrol und styrol
Authors: Tölle Von J. , Wittmer P. , Gerrens H. 
Published: April 2003

AbstractIm System α‐Methylstyrol (M1)/Styrol (M2) wurden die Copolymerisationsparameter für die anionische Copolymerisation bestimmt. Dazu wurde in Tetrahydrofuran als Lösungsmittel mit variiertem Monomerengehalt copolymerisiert. Die Reaktion kommt nach völligem Verbrauch des Styrols zum Stillstand, da α‐Methylstyrol unter den Versuchsbedingungen nicht homopolymerisiert. Aus dem Restgehalt an Monomeren kann man mit der integrierten Copolymerisationsgleichung die Parameter ermitteln. Gefunden wurden r1 = 0,015, r2 = 17 (25°C); r1 = 0,024, r2 = 28 (0°C); r1 = 0,029, r2 = 43 (−20°C).Auf Grund der sehr unterschiedlichen r‐Werte verschiebt sich das Monomerenverhältnis während der Copolymerisation erheblich. Alle Makromoleküle wachsen im gesamten Umsatzbereich („living”︁‐Polymerisation) und sind untereinander gleichartig aufgebaut, zeigen aber entlang der Kette eine starke Änderung der Zusammensetzung. Wir bezeichnen dies als „chemische Uneinheitlichkeit 2. Art”︁.
Synthesis of α.α′‐dibromomethyl sulfid and some reactions
Authors: Komoto Hiroshi , Kobayashi Hidehiko 
Published: April 2003

Abstractα.α′‐Dibromomethyl sulfide was obtained by reacting sym‐trithiane with bromine. Bromomethyl sulfenyl bromide was postulated as an intermediate in this reaction. The latter substance also condenses with ethylene to produce α.α′‐dibromomethyl ethyl sulfide. α.ω Dibromopolythimethylene was obtained by treating sym‐trithiane in bulk at 180°C with α.α′‐dibromomethyl sulfide. Polythiomethylene was obtained by treating α.α′‐dibromomethyl sulfide with water.
Vinyl polymerization. 194. Polymerization of methyl methacrylate in the presence of partially hydrolyzed polyvinyl acetate and water
Authors: Imoto Minoru , Takemoto Kiichi , Okuro Akyo , Izubayashi Masuji 
Published: April 2003

AbstractThe polymerization of methyl methacrylate was carried out without radical initiators,in the presence of partially hydrolyzed polyvinyl acetates and water. It was found that high molecular polyvinyl acetate and polyvinyl alcohol could not initiate the polymerization of inethyl methacrylate in the presence of water, while partially hydrolyzed polyvinyl acetates and formalized polyvinyl alcohol could initiate the polymerization. The results were discussed in connection with those of our series of studies.