Merouani Salim-Ramy, Kulagin Roman, Bondarenko Vladislav, Hosseinnezhad Ramin, Zaïri Fahmi, Vozniak Iurii
The Bio-Med-Chem Doctoral School of the University of Lodz and Lodz Institutes of the Polish Academy of Sciences, Banacha 12/16, Lodz 90-237, Poland.
Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza str., 112, Lodz 90363, Poland.
ACS Macro Lett. 2025 Feb 18;14(2):129-134. doi: 10.1021/acsmacrolett.4c00601. Epub 2025 Jan 12.
Traditionally, multiple shape memory polymers (multiple-SMPs) are created by forming either immiscible blends with high phase continuity (cocontinuous or multilayer phase morphology) or miscible blends that exhibit compositional heterogeneity at the nanoscale. Here, a new strategy for the fabrication of multiple-SMPs is proposed. It consists of the possibility of homogeneous mixing of immiscible polymers in the solid state under high pressure and shear deformation conditions. The blends formed in this way exhibit homogeneity of mixing down to the nanoscale, up to 40-95 nm. The transition from immiscible to miscible blends leads to an improvement not only in shape memory but also in the mechanical performance of the blends formed. Polypropylene (PP) and polystyrene (PS) were selected as pairs of immiscible polymers. The method of solid phase mixing is high pressure torsion (HPT). It was shown that the HPT-processed 50% PP/50% PS blend is able to exhibit an excellent triple shape memory effect (shape fixation of ∼94-95%, and recovery of ∼85-95%) with widely tunable (low and high) transition temperatures.
传统上，多种形状记忆聚合物（multiple-SMPs）是通过形成具有高相连续性的不混溶共混物（共连续或多层相形态）或在纳米尺度上表现出成分不均匀性的混溶共混物来制备的。在此，提出了一种制备multiple-SMPs的新策略。它包括在高压和剪切变形条件下固态不混溶聚合物均匀混合的可能性。以这种方式形成的共混物在纳米尺度（高达40 - 95纳米）下表现出混合均匀性。从不混溶共混物到混溶共混物的转变不仅导致形状记忆的改善，还导致所形成共混物的机械性能的提高。选择聚丙烯（PP）和聚苯乙烯（PS）作为不混溶聚合物对。固相混合的方法是高压扭转（HPT）。结果表明，经HPT处理的50%PP/50%PS共混物能够表现出优异的三重形状记忆效应（形状固定率约为94 - 95%，恢复率约为85 - 95%），且转变温度可广泛调节（低和高）。
