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Shape‐memory behaviors of biodegradable poly( L ‐lactide‐ co ‐ϵ‐caprolactone) copolymers
Author(s) -
Lu X. L.,
Cai W.,
Gao Z. Y.
Publication year - 2008
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.27703
Subject(s) - copolymer , elongation , caprolactone , materials science , ultimate tensile strength , degradation (telecommunications) , lactide , deformation (meteorology) , polymer chemistry , stress (linguistics) , shape memory alloy , biodegradation , composite material , chemical engineering , polymer , chemistry , organic chemistry , telecommunications , linguistics , philosophy , computer science , engineering
A series of biodegradable poly( L ‐lactide‐ co ‐ϵ‐caprolactone) (PCLA) copolymers with different chemical compositions are synthesized and characterized. The mechanical properties and shape‐memory behaviors of PCLA copolymers are studied. The mechanical properties are significantly affected by the copolymer compositions. With the ϵ‐caprolactone (ϵ‐CL) content increasing, the tensile strength of copolymers decreases linearly and the elongation at break increases gradually. By means of adjusting the compositions, the copolymers exhibit excellent shape‐memory effects with shape‐recovery and shape‐retention rate exceeding 95%. The effects of composition, deformation strain, and the stretching conditions on the recovery stress are also investigated systematically. A maximum recovery stress around 6.2 MPa can be obtained at stretching at T g − 15°C to 200% deformation strain for the PCLA70 copolymer. The degradation results show that the copolymers with higher ϵ‐CL content have faster degradation rates and shape‐recovery rates, meanwhile, the recovery stress can maintain a relative high value after 30 days in vitro degradation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008