Effects of Chain Segment Sequence Structures on the Properties of L-Lactide/ε-Caprolactone Copolymers
Polylactic acid(PLA)is one of the common biodegradable plastics.Copolymerization modification to introduce flexible chain segments(such as polycaprolactone,PCL)can improve the brittleness and poor flexibility of PLA,but the relationship between the chain segment sequence structures of PLA copolymers and their crystallization or mechanical properties is unclear.The poly(lactide-co-caprolactone)(PLCL)random copolymers and PLA-PCL-PLA(L-C-L)triblock copolymers were synthesized,and the effect of the chain segment sequence structures on the crystallization of the copolymers was investigated.The results showed that with the increase of caprolactone proportion,the average sequence length of PLA segment in PLCL shortens,and the crystallization rate and crystallinity of PLCL decreased dramatically,resulting in the decrease of Young's modulus and the increase of fracture strain.Conversely,the chain segment sequence structures of do not change,nor do its crystallization rate and crystallinity.However,the Young's modulus of L-C-L decreases and the fracture strain increases,showing the improvement of flexibility.
万方数据
维普
