| 摘要 |
<p>1,164,186. Polymerizing beta-lactones. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 21 June, 1967 [23 June, 1966], No. 28671/67. Heading C3R. Polyesters are made by polymerizing a betalactone (especially an alpha, alpha-dialkyl-betapropiolactone) in the presence of an anionic initiator and at least one chain-transit agent selected from (a) carboxylic acids and their anhydrides and acid halides, (b) phenols and thiophenols, (c) mercaptans and (d) enolizable compounds. Specified initiators are trimethylamine, triethylenediamine, tetraphenylphosphonium bromide, triphenylbutylphosphonium bromide, triphenylphosphine and betaines. Specified initiators are: (a) formic, acetic, propionic, beta-chloropropionic, isobutyric, pivalic, cinnamic, benzoic, alpha-naphthoic and adipic acids and certain of their anhydrides and acid chlorides; (b) phenol, p-cresol, alpha-naphthol, hydroquinone, thiophenol and m-tolyl mercaptan; (c) ethyl mercaptan, n-butyl mercaptan and n-nonyl mercaptan; (d) acetyl acetone and acetylacetio esters. Polymerization is effected at 0‹ to 350‹ C. in the presence or absence of a diluent. Examples describe the polymerization of pivalolactone.</p> |
