Yu Tianyu, Zhu Feilong, Peng Xiongqi, Chen Zixuan
School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China.
School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
Nanomaterials (Basel). 2022 Nov 22;12(23):4129. doi: 10.3390/nano12234129.
Shape memory polymers (SMPs) have aroused much attention owing to their large deformation and programmability features. Nevertheless, the unsatisfactory toughness and brittleness of SMPs still restrict their practical intelligent applications, e.g., textiles, flexible electronics, and metamaterials. This study employed nature-derived nanocelluloses (NCs) as the reinforcement to fabricate shape memory epoxy-based nanocomposites (SMEPNs). An acetylation modification approach was further proposed to ameliorate the intrinsic incompatibility between NCs and epoxy matrix. The storage modulus increases, and the shape memory effect (SME) sustains after acetylated nanocelluloses (ANCs) incorporation. The SMEPNs with 0.06 wt.% ANCs loading perform the most exceptional toughness improvement over 42%, along with the enhanced fracture strain, elastic modulus, and ultimate strength. The incorporated nanoscale ANCs effectively impede crack propagation without deterioration of the macromolecular movability, resulting in excellent mechanical properties and SME.
形状记忆聚合物（SMPs）因其大变形和可编程特性而备受关注。然而，SMPs令人不满意的韧性和脆性仍然限制了它们在诸如纺织品、柔性电子器件和超材料等实际智能应用中的发展。本研究采用天然来源的纳米纤维素（NCs）作为增强剂来制备形状记忆环氧基纳米复合材料（SMEPNs）。进一步提出了一种乙酰化改性方法，以改善NCs与环氧基体之间固有的不相容性。加入乙酰化纳米纤维素（ANCs）后，储能模量增加，形状记忆效应（SME）得以保持。负载量为0.06 wt.% ANCs的SMEPNs表现出最为优异的韧性提升，超过42%，同时断裂应变、弹性模量和极限强度也有所增强。掺入其中的纳米级ANCs有效地阻碍了裂纹扩展，且不会降低大分子的活动性，从而产生了优异的力学性能和形状记忆效应。
