Shrink-Resistant Poly(butylene adipate-co-terephthalate) Foam Reinforced with Crystalline Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Particles

Poly(butylene adipate-co-terephthalate) (PBAT) foam blown with CO2 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 degrees 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 CO2 desorption experiment and foam morphology observation.

Automated summary

In this study, PBAT foams with good dimensional stability were prepared by optimizing the blending ratios and foaming conditions. The presence of PHBV in PBAT melt improved the stiffness of the cell walls and facilitated the open-cell structure, resulting in lower shrinkage ratio and higher expansion ratio.