Synthesis of new compatibilizers to poly(lactic acid) blends

In this study, the effectiveness of three random copolymers based on blocks of poly(lactic acid) and polyethylene (PLA‐PE) used as compatibilizer in PLA and high density polyethylene blends (PLA/HDPE) was evaluated in terms of thermal and mechanical properties. The compatibilizers were synthesized by different ways: reactive extrusion (C1), ring opening polymerization of lactide with PE with —OH substituent group (PE‐OH) as initiator (C2) and polycondensation of lactic acid in presence of PE grafted with maleic anhydride (PE‐g‐MAH) (C3). The compatibilizers were used in two different proportions (5 and 15 wt%) and their efficiency was compared with a commercial compatibilizer (C0). The blends with C2 compatibilizer exhibited the highest tensile toughness (350% of increment compared with neat PLA/PE) because of the morphology attained. However, it was found that a relationship exists between the improvement of the compatibility and the loss of the thermal stability (−28°C) in PLA/HDPE blends. POLYM. ENG. SCI., 54:522–530, 2014. © 2013 Society of Plastics Engineers