Porous shape memory polymers (SMPs) are attracting people's attention due to their extensive application prospect. Herein, a novel and flexible method to produce bio-friendly polylactic acid (PLA)/polymethyl methacrylate (PMMA) shape memory foam by a two-step CO₂ microcellular foaming is proposed. The achieved foams exhibit outstanding shape memory performance, such as a maximum shape fixity ratio of 98 %, a maximum shape recovery ratio of 86 %, and further the recovery ratio remaining more than 75 % even after 10 compression-recovery cycles. The additive PMMA phases uniformly disperse with spherical morphology in nanoscale, and they result in the greatly decreased crystallinity and crystal size of PLA. Meanwhile, the extensive interfaces lead to increased crystal density. In this context, more amorphous molecular chains left in the cell wall act as reversible segments, and more numerous denser crystals act as net points, which together can decrease the resistance in the shape memory process, thus, facilitating the significant promotion of shape memory capability of the as-achieved PLA/PMMA foams. Therefore, it exhibits a promising future to produce environmentally friendly SMPs by a simple, cost-efficient, and clean microcellular foaming technology.

多孔形状记忆聚合物（SMP）由于其广阔的应用前景而引起人们的关注。本文中，一种新颖且灵活的方法通过两步式CO ₂生产生物友好型聚乳酸（PLA）/聚甲基丙烯酸甲酯（PMMA）形状记忆泡沫提出了微孔发泡。所获得的泡沫表现出优异的形状记忆性能，例如最大形状固定率98％，最大形状恢复率86％，并且甚至在10次压缩-恢复循环之后，恢复率也保持超过75％。添加剂PMMA相均匀地分散在纳米级的球形中，导致PLA的结晶度和晶体尺寸大大降低。同时，广泛的界面导致晶体密度增加。在这种情况下，更多的残留在细胞壁上的无定形分子链充当可逆链段，而更多的致密晶体充当网点，它们一起可以降低形状记忆过程中的阻力，从而有利于显着提高形状记忆能力所获得的PLA / PMMA泡沫。