| 摘要 |
1,205,093. Polylactones. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 27 Aug., 1969 [21 Oct., 1968], No. 49860/68. Heading C3R. Polyesters are made by polymerizing one or more #-propiolactones, at least 90% m. thereof being pivalolactone, in the presence of a polymeric anionic initiator having a solubility parameter of at least 9. The initiator is preferably a quaternized polyamide, a quaternized acrylamide-formaldehyde-secondary amine condensate, a polylactam, a polyoxadiazole-1,3,4, a polyphenylenetriazole - 1,2,4, a polydithiazole, a polyimide, a polybenzimidazole, a polyquinoxaline, a polybenzoxazole, a polybenzothiazole, a polyquinazolone, a polyimidazopyrrolone, a polyhydrazide (which may be quaternized), a polysulphonamide, a polysulphone, a polyphenylene ether having polar substituents such as nitro groups or bromine atoms, a polyanhydride, a polycarbonate, a polycarbamate, a polyurethane, a polyvinylpyrrolidone or polyvinylpyridine or a copolymer thereof. |
