Summary: We propose a novel recycling system for municipal food waste that combines fermentation and chemical processes to produce high‐quality poly‐L‐lactate (PLLA) biodegradable plastics. The process consists of removal of endogenous D, L‐lactic acid from minced food waste by a propionibacterium, L‐lactic acid fermentation under semisolid conditions, L‐lactic acid purification via butyl esterification, and L‐lactic acid polymerization via LL‐lactide. The total design of the process enables a high yield of PLLA with high optical activity (i.e., a high proportion of optical isomers) and novel recycling of all materials produced at each step, with energy savings and minimal emissions. Approximately 50% of the total carbon was removed, mostly as L‐lactic acid, and 100 kg of collected food waste yielded 7.0 kg PLLA (about 34% of the total carbon). The physical properties of the PLLA yielded in this manner were comparable to those of PLLA generated from commercially available. L‐lactic acid. Evaluation of the process is also discussed from the viewpoints of material and energy balances and environmental impact.

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