Optically transparent poly(methyl methacrylate) (PMMA)-based blends with significantly enhanced mechanical and shape memory properties have been successfully prepared via in-situ formation of micro-scale polylactide stereocomplex crystallites (sc-PLA) in the PMMA matrix in this work. To achieve this goal, a certain content of poly(_l-lactide) (PLLA) was firstly melt-blended with PMMA to obtain completely miscible PMMA/PLLA blends, and then an equimolar poly(_d-lactide) (PDLA) was incorporated into the blends, giving rise to the in-situ formation of sc-PLA between PLLA and PDLA. In this way, the micro-scale sc-PLA particles were successfully fabricated and homogeneously dispersed in the PMMA matrix. Consequently, these resultant PMMA/sc-PLA blends possess extremely superior optical transparency, even when the content of sc-PLA reaches up to 12 wt%. A further increase in the content of sc-PLA would lead to the formation of sc-PLA network and aggregation, resulting in the deterioration of optical transparency. Moreover, the incorporation of sc-PLA micro-particles significantly enhances the mechanical property of PMMA and the maximum (≈103 MPa) of these blends demonstrates 50% increase than that (≈70 MPa) of PMMA. More importantly, it has been found that the shape recovery performance of PMMA could be effectively improved by the incorporation of sc-PLA. The optimal shape recovery ratio (86%) and high shape fixing ratio (almost 100%) can be obtained for the PMMA/sc12 blend which exhibits excellent optical transparency. It is reasonable to believe that these optically transparent blends with largely enhanced mechanical and shape memory properties possess great application potential in advanced shape memory fields.

在这项工作中，通过在PMMA基质中原位形成微型聚丙交酯立体复合微晶（sc-PLA），已经成功制备了具有明显增强的机械和形状记忆性能的光学透明的聚甲基丙烯酸甲酯（PMMA）基共混物。为了实现这一目标，首先将一定含量的聚（_l-丙交酯）（PLLA）与PMMA熔融共混，以获得完全可混溶的PMMA / PLLA混合物，然后再等摩尔的聚（_d-丙交酯（PDLA）被掺入到共混物中，导致在PLLA和PDLA之间原位形成sc-PLA。以这种方式，成功地制备了微米级sc-PLA颗粒并将其均匀分散在PMMA基质中。因此，即使当sc-PLA的含量达到12wt％时，这些所得的PMMA / sc-PLA共混物也具有极好的光学透明性。sc-PLA含量的进一步增加将导致sc-PLA网络的形成和聚集，从而导致光学透明性下降。此外，掺入sc-PLA微粒显着增强了PMMA的机械性能，这些共混物的最大值（≈103MPa）比PMMA的最大值（≈70MPa）增加了50％。更重要的是，已经发现，通过掺入sc-PLA可以有效地改善PMMA的形状恢复性能。对于具有优异光学透明性的PMMA / sc12共混物，可以获得最佳的形状恢复率（86％）和高的形状固定率（几乎100％）。有理由相信，这些光学透明的共混物具有大大增强的机械和形状记忆性能，在先进的形状记忆领域具有巨大的应用潜力。