Modification of epoxidized natural rubber as a PLA toughening agent

In the present study, the modification of epoxidized natural rubber (ENR) was investigated to improve toughness of PLA. ENR-PLA copolymers were synthesized by 2 steps reactions. Acid hydrolysis of ENR to prepare macroinitiator (ENR-OH) and copolymerization with lactide to obtain ENR-PLA copolymers. The reaction time of acid hydrolysis and the lactide monomer loading was investigated. The optimum conditions were 8 h acid hydrolysis with 5wt% lactide loading to obtain ENR8-PLA5 copolymers. A series of samples of PLA blended with ENR-PLA copolymers was prepared using melt-blending. The blend of PLA with ENR8-PLA5 copolymers at 1 phr substantially improved the tensile properties. The elongation at break was increased 67%, and toughness was increased 64% compared to neat PLA. These results indicate that ENR8-PLA5 has potential as toughening agent for PLA. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48267.