Biodegradable reactive compatibilizers for efficient in-situ compatibilization of poly (lactic acid)/poly (butylene adipate-terephthalate) blends

The wide application of fully biodegradable polylactic acid/polybutylene terephthalate (PLA/PBAT) blends in environmentally friendly packaging were limited because of poor compatibility. Normal compatibilizers suffer from poor thermal stability and non-biodegradability. In this work, epoxy copolymer (MDOG) with different molecular structures were made of 2-methylene-1, 3-dioxoheptane, and glycidyl methacrylate as raw materials by free radical copolymerization. MDOG copolymers have good biodegradability and a high thermal decomposition temperature of 361 °C. The chemical reaction of the epoxy groups in MDOG with PLA and PBAT during the melting reaction improved the interfacial bonding by decreasing the particle size of PBAT. Compared to the PLA/PBAT blends, the tensile strength and fracture toughness of PLA/PBAT/MDOG blends were enhanced to 34.6 MPa and 115.8 MJ/m3, which are 25 % and 81 % higher, respectively. As a result, this work offers new methods for developing thermally stable and biodegradable compatibilizers, which will hopefully promote the development of packaging industry.