abstract |
Macrocyclic poly(alkylene dicarboxylate) oligomers are prepared by the reaction of a dicarboxylic acid chloride such as terephthaloyl chloride with at least one bis(hydroxyalkyl) ester such as bis(4-hydroxybutyl) terephthalate, in the presence of a Lewis acid as catalyst. Illustrative Lewis acids are ferric chloride, zinc chloride, zinc bromide, stannous bromide and antimony pentachloride. |