Hydroxy-telechelic copolyesters with well defined sequence structure through ring-opening polymerization

Full Paper: New well-defined macrodiols were prepared by ring-opening copol ymerization of lactones and cyclic diesters with a low molecular weight dio l. Suitable monomers are diglycolide, L,L-dilactide, epsilon-caprolactone, and rac-beta-butyrolactone. With exception of rac-beta-butyrolactone, the r eaction can be performed with or without a catalyst. The use of a catalyst influences the sequence structure of the telechelics. Copolyesterdiols from epsilon-caprolactone, diglycolide, and ethylene glycol with random, blocky , and intermediate structure were synthesized and characterized. The analog ous copolyesterdiols from L,L-dilactide, epsilon-caprolactone, and ethylene glycol were also prepared. The sequence structure of the random chains wit h diglycolide corresponds to a random distribution of glycolate units, that of the corresponding chains with L,L-dilactide exhibits a random distribut ion of L,L-dilactate units.