Owing to low melt strength and slow crystallization rate, poly (lactic acid) (PLA) foams are usually obtained by adding micro-/nano-particles, which inevitably sacrifices its green nature. Stereocomplex (SC) crystallites formed between poly (_L-lactic acid) (PLLA) and poly (_D-lactic acid) (PDLA) are appealing to endow PLA with promoted crystallization and superior heat resistance. Herein, microcellular PLA foams with high heat resistance and compression property were obtained using asymmetric PLLA/PDLA blends by a supercritical carbon dioxide (sc-CO₂) foaming technology. To facilitate the formation of SC, D-Mannitol (DM) with plentiful hydroxyl groups was applied, which notably promoted the formation of SC and subsequently the crystallization of homocrystallites (HC). The PLLA/PDLA/DM blends foams revealed much smaller cell sizes and higher cell densities compared with the neat PLLA. Furthermore, the PLA foam with 0.7 wt% DM exhibited good heat resistance under a loading of 1200 times, which displayed no changes after treating at 150 °C for 10 min, while the PLLA was obviously deformed. Additionally, the specific compressive modulus of PLLA/PDLA/DM blend foam was enhanced by 330% compared with the pure PLLA. Such fully-biobased PLA foams with superior heat resistance and high mechanical performance could be potentially applied into thermoformed food packaging.

由于熔体强度低、结晶速度慢，聚乳酸（PLA）泡沫通常是通过添加微/纳米颗粒获得的，这不可避免地牺牲了其绿色特性。_{聚( L-}乳酸)(PLLA)和聚( _D-乳酸)(PDLA)之间形成的立体络合物(SC)微晶对赋予PLA促进结晶和优异的耐热性具有吸引力。在此，通过超临界二氧化碳（sc-CO ₂）发泡技术，使用不对称 PLLA/PDLA 共混物获得了具有高耐热性和压缩性能的微孔 PLA 泡沫。为促进 SC 的形成，D- 使用具有大量羟基的甘露醇 (DM)，显着促进了 SC 的形成，随后促进了单晶 (HC) 的结晶。与纯 PLLA 相比，PLLA/PDLA/DM 共混泡沫具有更小的泡孔尺寸和更高的泡孔密度。此外，添加 0.7 wt% DM 的 PLA 泡沫在 1200 次负载下表现出良好的耐热性，在 150 ℃处理 10 分钟后没有变化，而 PLLA 明显变形。此外，与纯PLLA相比，PLLA/PDLA/DM共混泡沫的比压缩模量提高了330%。这种具有优异耐热性和高机械性能的全生物基 PLA 泡沫可以潜在地应用于热成型食品包装。