【摘要】 通过形状记忆性能测试、DSC和DMTA等热分析技术重点 ,探讨了结晶对EVA形状记忆性能的影响以及形状记忆性能的工艺性和使用性能的影响。结果表明 ,随着结晶度的增加 ,形状回复率变化不大 ,而形状固定率增加 ;热固性SMP的形状回复性由交联网络的完善程度决定 ,结晶度对其影响不大 ;结晶对形状记忆材料的响应温度和模量有较大影响 ,结晶度高响应温度高 ,常温模量高。形状固定率由聚合物的力学松弛特别是蠕变决定 ,结晶度只是其影响因素之一 ,不是决定性因素。从形状记忆机理出发初步揭示了影响热固性形状记忆高分子材料形状记忆性能的本质因素更多还原

【Abstract】 Four series of Ethylene-vinyl acetate copolymer (EVA): 5/2,14/2,18/3 and 18/25 were crosslinked by dicumyl peroxide (DCP) in two-step process and shape-memory polymer were prepared. Some macroscopic and microscopic factors such as crystallinity, which influence the shape-memory properties, were studied by Differential Scanning Calorimeter and Dynamical Mechanical Thermal Analysis. It is found that the crystallinity has little influence on the shape recovery rate;and with the increase of crystallinity, the shape fix rate increases a little. The study indicates that the shape recovery rate is determined by the degree of perfection of three dimensional crosslinking network, and the shape fix rate is determined by mechanodynamic relaxations. The crystallinity is a factor influencing the shape memory properties, but not a determining factor. With the increasing of crystallinity, the temperature of shape recovery and the modulus increase.更多还原