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L,L ‐Lactide and ε ‐Caprolactone Block Copolymers by a ‘Poly( L,L ‐lactide) Block First’ Route
Author(s) -
Florczak Marcin,
Libiszowski Jan,
Mosnacek Jaroslav,
Duda Andrzej,
Penczek Stanislaw
Publication year - 2007
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200700160
Subject(s) - copolymer , lactide , caprolactone , transesterification , alkoxide , polymer chemistry , materials science , block (permutation group theory) , chemistry , catalysis , organic chemistry , polymer , composite material , geometry , mathematics
L,L ‐lactide (LA) and ε ‐caprolactone (CL) block copolymers have been prepared by initiating the poly( ε ‐caprolactone) (PCL) block growth with living poly( L,L ‐lactide) (PLA*). In the previous attempts to prepare block copolymers this way only random copolyesters were obtained because the PLA* + CL cross‐propagation rate was lower than that of the PLA–CL* + PLA transesterification. The present paper shows that application of Al‐alkoxide active centers that bear bulky diphenolate ligands results in efficient suppression of the transesterification. Thus, the corresponding well‐defined di‐ and triblock copolymers could be prepared.