Premium
Biodegradable lactone copolymers. II. Hydrolytic study of ε‐caprolactone and lactide copolymers
Author(s) -
Malin M.,
HiljanenVainio M.,
Karjalainen T.,
Seppälä J.
Publication year - 1996
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/(sici)1097-4628(19960222)59:8<1289::aid-app12>3.0.co;2-1
Subject(s) - crystallinity , copolymer , hydrolysis , dispersity , polymer chemistry , caprolactone , materials science , lactide , amorphous solid , chemistry , polymer , organic chemistry , composite material
Copolymers of ε‐CL/L‐LA and ε‐CL/DL‐LA were allowed to age in a buffer solution of pH 7 at 23 and 37°C. The effects of time and temperature on the rate of hydrolysis were examined by various techniques including weighing (water absorption and weight loss), SEC (molecular weight and polydispersity), and DSC (thermal properties). For comparison, the hydrolytic behavior of PLLA, PDLLA, and commercial PCL homopolymers was investigated by the same methods. SEC measurements showed that molecular weights of the copolymers and PLA homopolymers started to decrease during the first week of hydrolysis, but significant mass losses occurred only much later. As expected, there was no change in either molecular weight or mass of PCL during the hydrolysis study. The kinetic results for copolymers and homopolymers were calculated to study the degradation mechanism. During hydrolysis, the crystallinity of the initially semicrystalline copolymers increased and some crystallinity appeared in the initially amorphous L‐LA‐containing copolymers. © 1996 John Wiley & Sons, Inc.