Fabrication of Biodegradable Poly(Butylene Adipate‐Co‐Terephthalate)/Poly(Butylene Succinate) Foams With High Expansion Ratio and Low Shrinkage Through Chain Extension Reactions

ABSTRACT The use of biodegradable plastic foams can alleviate environmental pollution problems caused by the widespread use of petroleum‐based non‐degradable plastic foams. However, fabricating biodegradable polymer foam with a high volume expansion ratio and low shrinkage remains a challenge. In this work, the poly(butylene adipate‐co‐terephthalate)/polybutylene succinate/chain extender (PBAT/PBS/CE) foams with a high volume expansion ratio and low shrinkage were successfully prepared. When the CE content is 0.8 wt%, the stabilized volume expansion ratio of the PBAT/PBS/CE 0.8 foam can be as high as 32, and the shrinkage rate is only 8.6%. Combining FTIR, rheological, and crystallization analysis, it is revealed that the inclusion of PBS increased the rigidity of the PBAT/PBS/CE foaming system, and the addition of CE increased the melt strength of the PBAT/PBS/CE foaming system. As a result of the high volume expansion rate, the compressive strain of the PBAT/PBS/CE 0.8 foam can be as high as 80%. The knowledge obtained from this study provides a method to prepare low shrinkage and a high volume expansion ratio by adjusting the rigidity and melt strength of polymer materials, which will facilitate the practical application of biodegradable plastic foams in the packaging, transportation, and construction industries.