Abstract
The isotropic melt of poly(l‐lactic acid) (PLLA) and random l/d‐lactide copolymers with 2% and 4% d‐isomer co‐units in the chain has been crystallized at 90 °C, which leads to growth of α′‐crystals. The maximum melting temperature of the α′‐crystals is around 150 °C in case of the homopolymer, and decreases by about 10 and 15 K in the random copolymers containing 2% and 4% d‐isomer co‐units, respectively. Analysis of the stability of the α′‐crystals requires suppression of formation of α‐structure, which is achieved by fast heating using a fast scanning chip calorimeter. For the PLLA homopolymer, the critical heating rate above which the α′/α‐transition is completely suppressed is around 30 K s–1, which significantly decreases in the copolymers due to the presence of d‐isomer co‐units. The slower kinetics of the melting‐recrystallization process in such random l/d‐lactide copolymers is explained by the required segregation of the chain defects. image
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
