摘要:

AbstractOriented poly(ethylene oxide) fibers form a complex with mercuric chloride, with the empirical formula (CH2CH2O)4·HgCl2. Tentatively the unit cell of the complex is orthorhombic with dimensions 13.5, 17.1, and 11.6 A. (c, the fiber axis). In spite of a major change in the unit cell, fiber orientation is maintained. The infrared spectrum of the complex is more detailed than that of the polymer alone, a fact consistent with a change from trans to gauche state of one OC bo

ISSN:0449-2951    

DOI:10.1002/pol.1964.100020601

出版商:John Wiley&Sons, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractA study has been made of the kinetics and mechanism of the liquid‐phase, γ‐radiation‐induced, alkyl chloride solution polymerization of ethylene. The γ‐radiation was provided by a 4.07 × 105r/hr. Co60source. The kinetics of these polymerizations were studied up to 10% conversion and over the temperature range 0 to −25°C. Three solvents (n‐propyl chloride,iso‐propyl chloride, andtert‐butyl chloride) were used with concentrations of ethylene ranging from 6.76 to 8.89 moles/l. Two different grades of ethylene were used: the first contained an upper limit of 1000 ppm of oxygen, the second 60 ppm. The ethylene containing only 60 ppm of oxygen was found to give a smaller induction period, and faster rate of polymerization than the ethylene containing 1000 ppm. Activation energies of 5.0 kcal./mole for the reaction inn‐propyl chloride and 7.4 kcal./mole for the reaction intert‐butyl chloride were observed for the temperature range studied. These values were higher than the 4.4 kcal./mole obtained for the bulk polymerization of ethylene in this temperature range. The order of the reaction with respect to ethylene concentration inn‐propyl chloride at 0°C. was found to be 1.41. Although the heterogeneity of the system is a complicating factor, this rate expression agrees well with the general scheme proposed for other heterogeneous polymerizations. Molecular weight information which shows an increase in molecular weight with increasing temperature leads to the conclusion that a termination step involving weakly reactive solvent

ISSN:0449-2951    

DOI:10.1002/pol.1964.100020602

出版商:John Wiley&Sons, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractThe rubber elasticity of lightly crosslinked, preswollen polymers is studied by both stress‐relaxation and torsion measurements. The equation of state of rubber elasticity is applied to evaluate their front factors. It is found that both elastic moduli and front factors decrease linearly as the diluent content increases. This relationship is independent of the type of crosslink and the diluent used. Properties of deswollen polymer networks are also investigated. No significant change in front factor is apparent before and after deswelling. All these observations are attributed to the network topology. One factor is that effective chemical crosslinks may be decreased by the formation of intramolecular loops. Also, trapped entanglements become less significant at higher diluent concentration

ISSN:0449-2951    

DOI:10.1002/pol.1964.100020603

出版商:John Wiley&Sons, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractHomopolymers and vinyl chloride copolymers have been prepared from the vinyl esters of mixed hydrogenated cyclized linolenic acid, 9,10‐dichlorostearic acid, 9,10,12,13‐tetrachlorostearic acid, 13,14‐dichlorobehenic acid, 9(10)‐phenylstearic acid and technical behenic acid. Vinyl 13,14‐dichlorobehenate (29%)‐vinyl chloride (71%) gave a copolymer with a brittle temperature of ‐2°C. All of the other copolymers with vinyl chloride had brittle temperatures of 16°C. or higher and behaved more like

ISSN:0449-2951    

DOI:10.1002/pol.1964.100020604

出版商:John Wiley&Sons, Inc.    

年代:1964

数据来源: WILEY

摘要:

Abstract9‐Vinylanthracene has been polymerized in a wide variety of cationic systems. Under these conditions of polymerization, the vinyl group and the center ring of the anthracene nucleus act as a 1,3,5‐triene system. Evidence for the structure of the product was obtained from infrared, ultraviolet, and particularly nuclear magnetic resonance spectroscopy. In the presence of trifluoroacetic acid, poly‐9‐vinylanthracene was converted to poly‐9,10‐dimethylen

ISSN:0449-2951    

DOI:10.1002/pol.1964.100020605

出版商:John Wiley&Sons, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractAn apparatus is described for the determination of number‐average molecular weights, based on the thermoelectric method as proposed by Hill. With this improved instrument, temperature differences of down to approximately 5 × 10−5°C. can be recorded. This allows determination of molecular weights up to 40,000 for the case of coiled macromolecules in a poor solvent. The accuracy of measurements, for all molecular weights, has been established by using benzene solutions of polyisobutenes of narrow and defined molecular weight distribu

ISSN:0449-2951    

DOI:10.1002/pol.1964.100020606

出版商:John Wiley&Sons, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractAllylD‐glucopyranoside tetraacetate is prepared by reaction of acetobromo‐D‐glucose with allyl alcool. The glycoside is not readily polymerized by free radical mechanism but on conversion to the epoxide with peracids, polymerization is easily induced with triethylaluminum. The product with a D. P. of 250 is soluble in organic solvents. On alkaline deacetylation the hydrophylic polymer is water soluble but the aqueous solution possess comparatively low visc

ISSN:0449-2951    

DOI:10.1002/pol.1964.100020607

出版商:John Wiley&Sons, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractPolybenzimidazoles have been prepared from 2,3‐, 2,7‐, and 2,6‐naphthalenedicarboxylic acids, 1,1′ ‐ferrocenedicarboxylic acid, maleic acid, fumaric acid, 4,5‐imidazole‐dicarboxylic acid, perfluoroglutaric acid, perfluorosuberic acid, and 3,3′ ‐diaminobenzidine. A copolymer has been prepared from a mixture of terephthalic acid and 2,2′‐diphenic acid. Thermogravimetric curves have been obtained for m

ISSN:0449-2951    

DOI:10.1002/pol.1964.100020608

出版商:John Wiley&Sons, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractThe living polymer technique of Szwarc has been employed to synthesize α,ω‐bifunctional derivatives of polybutadiene, polyisoprene, and polystyrene. The glycols derived from polybutadiene have been hydrogenated to give saturated glycols. The glycols from polyisoprene have been partially hydrogenated. Some block polymer esters and urethans have been characteri

ISSN:0449-2951    

DOI:10.1002/pol.1964.100020609

出版商:John Wiley&Sons, Inc.    

年代:1964

数据来源: WILEY

摘要:

AbstractRing‐opening polymerization of 5,6‐dideoxy‐5,6‐epithio‐1,2‐O‐isopropylidene‐α‐L‐idofuranose is catalyzed by boron trifluoride at 60°C. Soluble polymer is produced at monomer: catalyst ratio of 7 : 1 and monomer concentration 0.077Mafter 1 1‐hr. polymerization period. This polymer has a wide molecular weight distribution. A number‐average molecular weight of 72,000 is found for the first 40% of the polymer precipitated from aN,N‐dimethylformamide solution by the addition of water. Polymer is produced in increasing amounts as temperature is raised, catalyst concentration increased, and as water concentration is decreased. Transglycosylation may be the cause of branch formation or crosslinking. Hydrolysis of the soluble polymer removes isopropylidene groups to produce a water soluble reducing polymer which oxidizes with hypoiodite to a polymer

ISSN:0449-2951    

DOI:10.1002/pol.1964.100020610

出版商:John Wiley&Sons, Inc.    

年代:1964

数据来源: WILEY