聚己二酸对苯二甲酸丁二醇酯（PBAT）由于其低熔体强度，低模量使其在发泡过程中易发生泡孔塌陷、收缩等问题。本文利用熔点较高的聚乳酸（PLA，175 ℃）与熔点较低的PBAT（125 ℃）在180 ℃共混后以超临界二氧化碳（scCO2）为发泡剂，采用升温法（50 ℃浸渍，130 ℃发泡）制备了不粘结的PBAT/PLA发泡珠粒。旋转流变仪结果表明，随着PLA含量的增加，低频下共混物的储能模量、粘度均增加；差示扫描量热仪、偏光显微镜结果表明，发泡过程中不熔的PLA晶体与scCO2促进了共混物的结晶；扫描电子显微镜和发泡实物图表明，随着PLA含量的增加，共混物发泡珠粒的泡孔密度、体积膨胀率先增加后减小，平均泡孔尺寸减小。PLA含量为5 wt%时，泡孔密度最大达7.489×107 个/cm3，体积膨胀率达9.47倍，收缩率低至5.6%，发泡珠粒表面光滑。该法在不损失PBAT降解性的基础上，通过升温法工艺并辅助少量PLA改善PBAT泡孔形态和抗收缩性能，为工业化生产提供了简单方法。
Poly(butylene adipate‐co‐terephthalate) (PBAT) is prone to bubble collapse and shrinkage during the foaming process due to its low melt strength and modulus. In this paper, PBAT/PLA foamed beads were prepared using polylactic acid (PLA, 175 °C) with higher melting point and PBAT (125 °C) with lower melting point at 180 °C used scCO2 as foaming agent, using a heating-up method (impregnation at 50 °C and foaming at 130 °C). Rotational rheometer results showed that the storage modulus and viscosity of the blends increased with the increasing of PLA content. Differential scanning calorimetry and polarizing microscope results show that PLA crystals do not melt during foaming and that scCO2 promotes crystallisation of the blends. Scanning electron microscopy and foaming diagrams show that the pore density and volume expansion of the blended foamed beads increase and then decrease with increasing PLA content, and the average mean diameter decreases. With a PLA content of 5 wt%, the cell density reaches a maximum of 7.489 x 107 cells/cm3, the expansion rate reaches 9.47 times, the shrinkage rate is as low as 5.6% and the surface of the foamed beads is smooth. This method provides a simple method for industrial production by improving PBAT cell morphology and shrinkage resistance through a heating up method with a small amount of PLA, without loss of PBAT degradability.