交联乙烯-醋酸乙烯酯共聚物/聚多巴胺复合材料的制备及光驱动形状记忆效应

Preparation of Cross-Linked Poly(ethylene-co-vinyl acetate)/Polydopamine Composites and Light-Driven Shape Memory Effect

通过熔融共混制备得到交联乙烯-醋酸乙烯酯共聚物(CEVA)/聚多巴胺(PDA)复合材料,研究了交联程度对乙烯-醋酸乙烯酯共聚物(EVA)形状记忆性能的影响,以及引入PDA纳米微球在基体中的光热效果。动态热机械分析表明,交联度的提高有助于减小塑性流动,从而使材料具有更稳定的形状记忆效应。PDA(质量分数0.8%)的引入赋予了CE-VA良好的光热性能,在0.546W/cm^(2)的近红外光下照射18s,温度可以由室温上升到106℃。在近红外光开启和关闭时,由于PDA光热特性致使CEVA晶区形态发生可逆变化,从而形成了近红外光触发的可逆双向形状记忆效应。

Cross-linked poly(ethylene-co-vinyl acetate)(CEVA)/polydopamine(PDA)composites were prepared by melt blending,and the influence of the degree of cross-linking on the shape memory properties of EVA,the photothermal effects of introducing PDA nanospheres in the matrix were investigated.Dynamic thermomechanical analysis show that the increase of gel content contributes to reduce plastic flow,which result in a more stable shape memory effect of the material.The introduction of PDA(mass fraction of 0.8%)endows CEVA with good photothermal properties,with the temperature rising from room temperature to 106℃when irradiated with NIR light at 0.546 W/cm^(2) for 18 s.During NIR light on and off,the PDA photothermal properties lead to reversible changes in the morphology of the CEVA crystal region,resulting in a reversible two-way shape memory effect triggered by NIR light.