Modification of epoxidized natural rubber as a PLA toughening agent

ABSTRACT 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. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 48267.