Improved properties of biodegradable poly(ethylene adipate-co-terephthalate) (PEAT)/thermoplastic starch (TPS) composite films via chemical crosslinking: Enhanced mechanical properties, water-oxygen barrier performance, and compatibility

In order to address the poor compatibility between thermoplastic starch (TPS) and polyester during the blending process, this study employed the melt blending method to prepare poly (ethylene adipate- co -terephthalate) (PEAT)/thermoplastic starch (TPS) composite films. A series of composite films were evaluated for mechanical properties, micromorphology, thermal behavior, water absorption, and water vapor and oxygen barrier, systematic study was conducted on the effect of the amount of reactive chain extender poly((phenyl isocyanate)- co -formaldehyde) (PAPI) addition for the performance of PEAT/TPS/PAPI composite films. The results indicate that PAPI, as the reactive compatibilizer, effectively improves the interfacial adhesion of PEAT/TPS blends. The research findings indicate that PAPI enhances the compatibility between PEAT and TPS by forming urethane bonds. The incorporation of PAPI significantly enhances the mechanical properties of the composite film, with tensile strength and tensile modulus increasing by 62 % and 88 % respectively, and toughness increasing by 48 %. Moreover, the incorporation of PAPI has enhanced the water vapor barrier properties of the composite film by 44 %, and improved its oxygen barrier properties by 26 %. The results obtained in this study provide a reference for the manufacture of PEAT/TPS composites, which will facilitate the practical application of PEAT/TPS composite films in the packaging film.