摘要:

AbstractThe polymerization of toluene with aluminum chloride and cupric chloride was performed in carbon disulfide and in a neat system. The solvent reaction produced an insoluble, light‐brown product which did not melt below 350°C. In the neat system, polymerization was much more vigorous, yielding a dark, purple‐brown solid with mp ∼250°C and molecular weight of 634. Infrared, NMR, and ultraviolet spectroscopy, along with elemental analysis and oxidative degradation, indicated that the backbone chain containso‐polyphenylene units with the methyl group situated in the 4‐position. Somep‐polyphenylene structures may also be present. Evidence for small amounts of benzyl and polynuclear moieties was obtained. The mechanistic aspects are discussed. Our principal conclusions concerning oligomer structure are in disagreement with th

ISSN:0449-296X    

DOI:10.1002/pol.1969.150070111

出版商:John Wiley&Sons, Inc.    

年代:1969

数据来源: WILEY

摘要:

Abstract2,5‐Dichlorothiophene was polymerized to a solid in 93% yield on treatment with aluminum chloride–cupric chloride in carbon disulfide under mild conditions. The product is believed to be poly‐5‐chloro‐2,3‐thienylene on the basis of elemental analysis and infrared and NMR spectral data. Hydrogen chloride was collected in 90% of the theoretical amount. Dimer‐ and tetramer‐type fractions were isolated from the polymer. 2,3,5‐Trichlorothiophene underwent an analogous transformation in trichlorobenzene at 90–100°C. Polythienylenes coupled through the 2,3‐positions have not been reported previously. The net effect of the reaction is nuclear coupling by dehydrohalogenation. We believe that the mechanism involves cationic polymerization accompanied by loss of hydrogen chloride. 2‐Chlorothiophene and thiophene gave pro

ISSN:0449-296X    

DOI:10.1002/pol.1969.150070112

出版商:John Wiley&Sons, Inc.    

年代:1969

数据来源: WILEY

摘要:

AbstractThe condensation polymers formed by condensing aromatic hydrocarbons or their derivatives with aromatic acids are quite conductive. The room temperature resistivities of 42 polymers studied here range from 102to 1012ohm‐cm. It is found that the resistivities are inversely related to the number of fused rings in the hydrocarbon portion of the monomer for either the homopolymers or copolymers. The resistivities are strongly dependent, inversely, upon the acid strength of the acid monomer reactants. For all the polymers studied, the conductivity σ depended upon the pressurePas ln(σ/σ0) = (b*/k)P1/2whereb*is seen to be an inverse function of the number of fused rings in the monomer in accord with theory. The resistivity ρ varied with absolute temperatureT, as ln ρ ∞ (1/T) for all polymers. Thermoelectric powers were determined, and the various relationships established among energy interval, resistivity at “infinite temperature,” carrier concentrations and mobility ratios, number of fused rings, and pressure coefficients are discussed. The polymers arep‐type. Doping by Be++or Cu++has a small effect, increasing the conductivity slightly. Electron spin concentrations and carrier concentrations are directly related among the polymers, being found nearly equal for the most conductive but differing by up to nine orders of magnitude in the least condu

ISSN:0449-296X    

DOI:10.1002/pol.1969.150070113

出版商:John Wiley&Sons, Inc.    

年代:1969

数据来源: WILEY

摘要:

AbstractSelf‐protective polyesters were synthesized in two ways: by polymer analog transformations on polymers obtained and by introduction of inhibiting groups into the polymer during synthesis. It is shown that the Fries rearrangement takes place in the aromatic polyesters in the presence of the Friedel‐Crafts catalysts and on ultraviolet irradiation as well. Thermogravimetric analysis of the rearranged polymers and investigations of the influence of the ultraviolet irradiation on their properties show that the rearrangement markedly increases the photochemical and thermal stability of the polymers. Photostabilization may also be accomplished by the introduction of inhibiting groups, such as hydroxyl, sulfur, or phosphorus into the polymer molec

ISSN:0449-296X    

DOI:10.1002/pol.1969.150070114

出版商:John Wiley&Sons, Inc.    

年代:1969

数据来源: WILEY

摘要:

AbstractTrialkylboron–oxygen, an active, low‐temperature free‐radical initiator, has been employed to investigate the effects of very low temperatures on the copolymerizations of vinyl acetate withcisandtrans‐1,2‐dichloroethylenes. The low temperatures favor the propagation rate relative to the transfer rate, such that high molecular weight copolymers containing substantial quantities of 1,2‐dichloroethylene can be prepared. The molecular weights of the copolymers depend only on the amounts of 1,2‐dichloroethylene in the copolymers, regardless of the isomer which takes part in the copolymerization. Since the double bond of thetransisomer is about six times as reactive as that of thecisisomer, this indicates that the dominating chain transfer reaction occurs by chlorine atom elimination subsequent to the addition of the dichloroethylene unit to the growing free radical chain. It is suggested that a similar chain‐transfer mechanism occurs in the polymerization of vinyl chloride, wherein an infrequent head‐to‐head placement of monomer unit is followed by ejection of a chlorine atom to form an olefinic bond and termination of that growing chain. The presence of the 1,2‐dichloroethylene unit in the copolymer increases the glass transition temperature approximately 1°C per weight per cent copolymerized

ISSN:0449-296X    

DOI:10.1002/pol.1969.150070115

出版商:John Wiley&Sons, Inc.    

年代:1969

数据来源: WILEY

摘要:

AbstractThe γ‐ray copolymerization of carbon monoxide with cyclic ethers, such as ethylene oxide, phenyl glycidyl ether, 1,3‐dioxolane, 2‐vinyl‐1,3‐dioxolane, terahydrofuran, 1,4‐dioxane, and acetaldehyde was studied. A yellowish or brownish powdery copolymer was obtained in most of the cases examined. The infrared spectra showed that copolymers containing the ester structural unit were produced in the copolymerization with cyclic ethers which have no vinyl groups, and that a copolymer containing a ketone structure was produced from cyclic ether having vinyl group. It was found that the copolymer with ethylene oxide also had a β‐propiolactone ring structure at the chain end or the side chain. The copolymers were confirmed to be partially crystalline from the x‐ray diffraction diagrams. Further, a ring‐opening polymerizability of the cyclic ether by γ‐radiation was discussed. And it was found that as the bond dissociation energy between the carbon–oxygen linkage of the cyclic ether is small, the polymer yield both in the homopolymerization and copolymerization with carbon monoxide is high. A mechanism for the copolymerization is proposed on

ISSN:0449-296X    

DOI:10.1002/pol.1969.150070116

出版商:John Wiley&Sons, Inc.    

年代:1969

数据来源: WILEY

摘要:

AbstractThe unit cell dimensions of isotactic polyvinylcyclopropane were determined, based on crystalline, oriented fiber and film samples. Two structures were found: (1) a hexagonal structure witha= 13.6 Å,c= 6.48 Å, 31helix, space group P31and P32, ρ(calc) = 0.9805 g/cm3, ρ(obs) = 0.975 g/cm3; (2) a tetragonal structure witha= 15.21 Å,c= 20.85 Å, 103helix, space group I4, ρ(calc) = 0.926

ISSN:0449-296X    

DOI:10.1002/pol.1969.150070117

出版商:John Wiley&Sons, Inc.    

年代:1969

数据来源: WILEY

摘要:

AbstractTrioxane–1,3‐dioxolane copolymers of high molecular weights and good thermal stability are obtained with high yields by a crystallization‐polymerization method. The feed consists of concentrated solutions of trioxane in cyclohexane in the presence of dissolved 1,3‐dioxolane. The 1,3‐dioxolane/trioxane molar ratio in the feed lies in the range 2 to 10%. The results are compared with those obtained from isothermal copolyme

ISSN:0449-296X    

DOI:10.1002/pol.1969.150070118

出版商:John Wiley&Sons, Inc.    

年代:1969

数据来源: WILEY

摘要:

AbstractSeveral α‐olefins containing the trifluoromethyl group were prepared and characterized. 4,4,4‐Trifluoro‐1‐butene, 3‐trifluoromethyl‐1‐butene, 5,5,5‐trifluoro‐1‐pentene, and 4‐trifluoromethyl‐1‐pentene were homopolymerized with VCl3–Al(i‐Bu)3catalyst. The trifluorobutenes gave low‐melting polymers with low fluorine contents. Polymers obtained from the trifluoropentenes were soluble having moderately high intrinsic viscosities. Copolymerizations of these monomers with their nonfluorinated homologs by the same catalyst system indicated low reactivities of the fluoromonomers. Nuclear magnetic resonance spectra of the fluorinated and nonfluorinated monomers and their respective spectroscopic studies with the catalyst (C5H5)2TiCl2–Al(CH3)3indicated an electron deficiency of the vinyl group of the fluorobutenes. This was related to the inductive effect of the trifluoromethyl group. The inductive effect of this group was absent in the fluoropentenes and the nonfluorinated monomers. The electron‐deficient vinyl group of the fluorobutenes apparently did not allow these monomers to coordinate with the active sites of the catalyst. Polymerization studies of the nonfluorinated monomers, 1‐butene, 3‐methyl‐1‐butene, 1‐pentane, and 4‐methyl‐1‐pentene, with the catalyst VCl3–Al(Bu)3, were performed in the presence of compounds containing the trifluoromethyl group. Results indicated that this group did not retard the rate of polymerization of these monomers. Evidence is presented to show that a catalytic amount of benzotrifluoride enhanced the rate of polymerization of α‐olefins, particularly that

ISSN:0449-296X    

DOI:10.1002/pol.1969.150070119

出版商:John Wiley&Sons, Inc.    

年代:1969

数据来源: WILEY

摘要:

AbstractThe photo‐oxidation of PVC and its model compounds, thedl‐ andmeso‐2,4‐dichloropentanes, were studied by high‐resolution NMR spectroscopy. The structure, CHClCH2COCH2 was found to be present in PVC after photo‐oxidation. Two peaks, which corresponded to the CHCl and CH2groups next to the carbonyl group, were observed in carbon disulfide–acetone‐d5mixture, at 6.15 and 7.25τ, respectively. From the NMR spectra, the ratio of the CH2to CHCl protons in PVC and the model compounds were found to increase linearly with the time of photo‐oxidation after induction periods. The initial rates of the model compounds were comparable with that of PVC; i.e., 1.6 × 10−2hr−1, at 30°C. Since similar gaseous products were also detected by mass spectrometry in the initial stage, their photo‐oxidation probably assumed the same rate‐determining step. According to the results that thedl‐2,4‐dichloropentane was photo‐oxidized 1.5 times faster than themeso‐compound, it would be likely that the syndiotactic sequences in PVC might be more easi

ISSN:0449-296X    

DOI:10.1002/pol.1969.150070120

出版商:John Wiley&Sons, Inc.    

年代:1969

数据来源: WILEY