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Date of Publication:2009-01-01

Journal:功能材料

Affiliation of Author(s):化工学院

Issue:1

Page Number:123-125,129

ISSN No.:1001-9731

Abstract:Poly(DL-lactide-co-Ε-caprolactone) copolymers were prepared by copolymerization of DL-LA and Ε-CL using nontoxic magnesium octoate as catalyst in bulk. Microstructure analyses of the resulting copolymers were performed by means of13CNMR spectroscopy. Two modes of transesterification occurred during the copolymerization process and played an important role in the redistribution of comonomer sequences toward randomness. The copolymer composition has a profound influence on the average block length of lactidyl and caproyl units (LLLeand LeC). Both LLLeand LCeincreased as the relative proportions of their respective monomers increased. The thermal properties and crystallization of the copolymers were investigated by DSC and XRD. The results showed that a close relationship between copolymer crystallinity and the length of the copolymer sequences. All the copolymers exhibited a single Tg. The experimental Tgs were in agreement with the calculated values from Fox equation. It can be concluded that the copolymers are random, or comprise a mixture of compatible block copolymers.

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