Study on morphological, mechanical, thermal, barrier, rheological, and biodegradation properties of poly(butylene adipate‐co‐terephthalate)/thermoplastic starch/poly(propylene carbonate)‐g‐polyurethane biodegradable films

Abstract

Bioplastic films with excellent physical properties and barrier properties were successfully prepared from poly(butylene adipate‐co‐terephthalate) (PBAT), thermoplastic starch (TPS), and poly(propylene carbonate)‐g‐polyurethane (PPCU). The rheological, mechanical, barrier, dynamic mechanical properties, and microstructure of the PBAT/TPS/PPCU blend films were studied. The proportion of PPCU controlled the morphology and continuous development of PBAT/TPS/PPCU blends. The increase of PPCU led to the formation of different phase morphologies of the PBAT/TPS/PPCU blends, including “island‐sea,” “quasi‐co‐continuous,” and “co‐continuous” structures. This phase transformation of PPCU emerges as a pivotal driver in the improvement of mechanical properties, resulting in a substantial enhancement from 23.4/24.7 MPa to 37.7/35.6 MPa. Furthermore, the addition of 40%PPCU led to a remarkable 29.6% reduction in the water vapor permeability of the PBAT/TPS/PPCU film. Finally, the increase of PPCU can improve the aging resistance of PBAT/TPS/PPCU films. The films exhibit good mechanical properties and barrier performance, indicating PBAT/TPS/PPCU film potential as environmentally viable substitutes for conventional plastics in the packaging domain.