Preparation of Polymer Blends between Poly(Lactic Acid) and Poly(Butylene adipate-co-terephthalate) and Biodegradable Polymers as Compatibilizers

Biodegradable polymers having good toughness were used as compatibilizers for the polymer blend system of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) to replace the inorganic or non- degradable compatibilizers. Biodegradable polymers such as poly(butylene succinate) (PBS), poly(butylene adipate- co-terephthalate) (PBAT), and poly(hydroxybutylate-co-valerate) (PHBV) have capability to mix with PLA. Polymer blends of PLA/PBAT (70:30) were added with 1, 3 and 5 phr of PBS, PBSA and PHBV. It was found that thermal property of polymer blends slightly decreased, melting temperature (Tm) of the compositional polymers were almost not changed which indicated the phase separation of compositions. The melt flow of polymer blends increased with increasing amount of PBS while it was not changed with addition of PBSA and PHBV. Modulus of polymer blend with addition of 1 wt% PHBV was slightly increased while modulus of most of the polymer with addition of PBS and PBSA decreased. The results confirmed the phase separation of polymer components.