TY - JOUR
T1 - Biodegradable lactone copolymers. II. Hydrolytic study of ε-caprolactone and lactide copolymers
AU - Malin, M.
AU - Hiljanen-Vainio, M.
AU - Karjalainen, T.
AU - Seppälä, J.
PY - 1996/2/22
Y1 - 1996/2/22
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0030083851&partnerID=8YFLogxK
U2 - 10.1002/(SICI)1097-4628(19960222)59:8<1289::AID-APP12>3.0.CO;2-1
DO - 10.1002/(SICI)1097-4628(19960222)59:8<1289::AID-APP12>3.0.CO;2-1
M3 - Article
AN - SCOPUS:0030083851
SN - 0021-8995
VL - 59
SP - 1289
EP - 1298
JO - Journal of Applied Polymer Science
JF - Journal of Applied Polymer Science
IS - 8
ER -