非共价键交联聚乙烯醇的热致型形状记忆性能

Non-Covalent Cross-Linked Poly(Vinyl Alcohol)with Thermal-Responsive Shape-Memory Effect

采用冻融循环法制备具有热致型形状记忆效应的非共价键交联聚乙烯醇,研究了材料的热致型形状记忆行为,考察了聚合物浓度、冻融循环次数及溶剂种类对物理交联SM-PVA性能的影响。通过差示扫描量热分析、热失重分析、动态力学分析、力学性能测试、溶胀平衡测试及形状回复实验测试了不同样品的热力学性能及形状记忆性能。结果表明,所有样品都有很好的热稳定性;质量分数为15%PVA水溶液所制样品的形状回复性能最好;增加冻融循环次数可有效提高材料储能模量和拉伸强度;由于水分子起到增塑剂的作用,用水做溶剂所得样品形变回复率高,50℃可达75%。

Thermal-induced shape-memory polymers based on non-covalent cross-linked poly（vinyl alcohol）（SM-PVA）were prepared through freezing and thawing cycles（FTC）.Thermal induced shape memory effect（SME）of prepared material was studied.The effect of polymer concentration,freezing-thawing cycles and types of solvent on the properties of physically cross-linked SM-PVA was studied.DSC,TGA,DMA,mechanical and swelling equilibrium tests and bending tests were carried out to study the thermal-mechanical properties and SME.The results show that fabricated materials possess good thermal stability;the samples prepared by15% PVA solution exhibit more excellent shape recovery compared with others prepared under the same conditions;increasing freezing-thawing cycles would help to improve storage modulus and tensile strength;moreover,when water acts as solvent,shape recovery ratio could rise up to 75%at 50℃ due to plasticizing effect of water molecules.