Enhanced thermostability of polylactic acid by N-(4-carboxyphenyl) maleimide–alt–styrene

The heat-resistant agent N-(4-carboxyphenyl) maleimide–alt–styrene (PCS) was used to modify polylactic acid (PLA) in order to improve the thermostability of PLA. The heat deflection temperature (HDT), thermodegradation, crystallization behavior and thermomechanical property were analyzed. The HDT of PLA added with PCS increased by about 10°C, and after heat treatment, the improvement of HDT was more significant. The thermal degradation behavior of PLA before and after modification hardly changed. The crystallinity ( X c ), crystallization rate ( 1/t 1/2 ) and crystallization temperature ( T c ) of the composite material were significantly improved, but the crystalline structure did not change. The crystallinity of the composite material was twice that of pure PLA, the crystallization rate increased by about 30% and the crystallization temperature went up more than 10°C. The storage modulus ( E’) of PLA was improved by PCS due to enhancing its crystallinity. The thermostability of PLA was significant improved after PCS is added.