摘要:

AbstractThem‐cresol‐insoluble polymer of ϵ‐caprolactam obtained with NaAl(Lac)4catalyst is converted to a soluble polymer on treatment with dilute (0.1 wt‐%) aqueous hydrochloric acid without any accompanying degradation of polymer chain. Aluminum contained in the polymer was not removed completely by extensive extraction with methanol, regardless of the solubilities of the polymers. This fact suggests the existence of two forms of aluminum in the polymer: one contributes to insolubility of the polymer and the other does not. The polymerization behavior in the case of NaAl(Lac)3(OEt) was somewhat different from that of NaAl(Lac)4and of NaAl(Lac)3(NHBu). These results are considered to reflect a difference in the stability of the Al‐O, Al‐(Lac), and Al‐N bonds i

ISSN:0449-296X    

DOI:10.1002/pol.1970.150080221

出版商:John Wiley&Sons, Inc.    

年代:1970

数据来源: WILEY

摘要:

AbstractThis paper reports the results of copolymerization of trimethylvinylsilane and dimethyldivinylsilane, respectively, with maleic anhydride. The former forms a 1:1 alternating copolymer while the latter, being a 1,4‐pentadiene, forms a 1:2 cyclocopolymer. Consistent with the theory that charge‐transfer complexes are involved in certain copolymerizations, it has been shown in this work that both of the vinyl silanes studied form charge‐transfer complexes with maleic anhydride. The stoichiometric composition of these complexes have been shown by ultraviolet analysis to be 1:1 molar complexes. The equilibrium constants for complexation of trimethylvinylsilane and dimethyldivinylsilane with maleic anhydride have been determined by NMR and are 0.061 and 0.1071./mole, respect

ISSN:0449-296X    

DOI:10.1002/pol.1970.150080222

出版商:John Wiley&Sons, Inc.    

年代:1970

数据来源: WILEY

摘要:

AbstractThe effects of lithiumtert‐butoxide on rates of initiation, propagation, and polymerization of butyllithium‐initiated polymerization of butadiene and styrene were examined. Toluene and cyclohexane were used as solvent and the experiments covered BuLi/‐t‐BuOLi ratios from 1:0 to 1:6. Both polymerization and propagation rates declined in the presence of alkoxide. The initiation rate in cyclohexane increased to a maximum at BuLi/t‐BuOLi ratio of 1:0.5 and then decreased. A mechanism of rapid dissociation of butyllithium oligomer by alkoxide and multiple complexation of butyllithium with excess alkoxide is proposed. Lithium alkoxide also reduced the copolymerization rate but did not affect the copolymerization characteristies. Water reacted with organolithium compound rapidly to form hydroxide. It was found that the hydroxide reacted very slowly with more organolithium compound in hydrocarbon solution to form oxide. Their effects on polymerization were inv

ISSN:0449-296X    

DOI:10.1002/pol.1970.150080223

出版商:John Wiley&Sons, Inc.    

年代:1970

数据来源: WILEY

摘要:

AbstractPrevious work from this laboratory has shown that certain 1,4‐dienes which readily undergo cyclocopolymerization with certain alkenes also form charge‐transfer complexes with the same alkenes. The results observed and the proposed cyclocopolymerization mechanism are consistent with participation of the charge‐transfer complex as a distinct species in the copolymerization. It was the purpose of this investigation to determine whether there was a dilution effect on the relative reactivities of the monomers in support of the charge‐transfer participation concept, and whether the results of a suitable terpolymerization study would also support this postulate. In the divinyl ether–fumaronitrile system, the maximum rate of copolymerization occurred at a monomer feed ratio of 1:2 and the composition of the copolymer was also 1:2 at a total monomer concentration of 3 mole/l. However, when the concentration was progressively lowered to 0.5 mole/l. at the same monomer feed ratio, the fumaronitrile content of the copolymer decreased in a linear manner. In a series of terpolymerization experiments with the divinyl ether–maleic anhydride–acrylonitrile system, it was shown that the divinyl ether–maleic anhydride ratio in the terpolymer was always less than 1:1 and had an upper limit of 1:2, regardless of the feed ratio of the termonomers. These results are consistent with the participation of the charge‐transfer complex of divinyl ether and maleic anhydride in a copolymerization process with either maleic anhydride or acrylonitrile

ISSN:0449-296X    

DOI:10.1002/pol.1970.150080224

出版商:John Wiley&Sons, Inc.    

年代:1970

数据来源: WILEY

摘要:

AbstractA series of polyiminobenzothiazoles was synthesized by the polymerization of either 2,6‐dichloro‐ or 2,6‐diphenoxybenzobisthiazole with a number of aromatic diamines. A polymer was also obtained from the self‐condensation of either 2‐chloro‐ or 2‐phenoxy‐6‐aminobenzothiazole. The polymers were characterized by their elemental analysis and infrared spectra. Thermogravimetric analysis, differential thermal analysis, and softening under load were used to evaluate their thermal properties. The polymers were found to be light tan to brown powders which showed only slight softening below their decomposition temperatures. Onset of breakdown under thermogravimetric analysis in a nitrogen atmosphere generally occurred at 375–400°C. The polymers were sparingly soluble in organic solvents and had inherent viscosities in th

ISSN:0449-296X    

DOI:10.1002/pol.1970.150080225

出版商:John Wiley&Sons, Inc.    

年代:1970

数据来源: WILEY