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Polymerization of glycolide promoted by ω‐Al‐alkoxide poly(ϵ‐caprolactone) macro‐initiators and formation of stable colloidal dispersions
Author(s) -
Barakat Ibrahim,
Dubois Philippe,
Jérǒme Robert,
Teyssié Philippe,
Mazurek Mieczyslaw
Publication year - 1994
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19940880118
Subject(s) - alkoxide , polymerization , copolymer , polymer chemistry , colloid , caprolactone , materials science , transmission electron microscopy , aqueous solution , chemical engineering , chemistry , organic chemistry , catalysis , polymer , nanotechnology , composite material , engineering
Abstract Block polymerization of glycolide (GA) and ϵ‐caprolactone (ϵ‐CL) has been initiated with aluminum alkoxides, such as Al(O i Pr) 3 and Et 2 AlOCH 2 X (where X = ‐CH 2 ‐Br and ‐CH 2 O‐C(O)‐C(Me)=CH 2 ), in THF at 40°C. Structure and composition of block copolyesters have been characterized with respect to the molecular weight by NMR spectroscopy and thermal analysis. Copolymerization is typically living, so that block copolyesters have been synthesized with predictable molecular weight and composition. The inherent insolubility of polyglycolide block is responsible for the heterogeneity of the polymerization medium and formation of stable, non‐aqueous colloidal dispersions. This effect is especially pronounced at high GA/ϵ‐CL molar ratios. Colloidal dispersions have been analyzed by transmission electron microscopy (TEM) and photocorrelation spectroscopy (PCS).