Shrink-Resistant Poly(butylene adipate-<i>co</i>-terephthalate) Foam Reinforced with Crystalline Poly(3-hydroxybutyrate-<i>co</i>-3-hydroxyvalerate) Particles
Haonan Sheng, Zijian Zhou, Haikuo Yan, Yuyuan Yao, Li Zhang
Abstract
Poly(butylene adipate- co -terephthalate) (PBAT) foam blown with CO 2 exhibits severe shrinkage problems, with a substantial post-foaming shrinkage ratio reaching up to 80%. In this study, we reported a useful method to prepare PBAT foams with good dimensional stability by simply optimizing the polymer blending ratios and foaming conditions. The foaming behaviors showed that the PBAT/poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (PHBV) blend with a mass ratio of 80/20 possessed an expansion ratio of up to 29.3 at 110 °C, with a shrinkage ratio of less than 5%. Moreover, the presence of 20 wt % PHBV in PBAT melt could not only facilitate the open-cell structure but also improve the stiffness of the cell walls. A possible mechanism for the reinforced foam stability is proposed based on the results of the CO 2 desorption experiment and foam morphology observation.