基于形状记忆聚合物复合材料的双向形状记忆行为

Two-way Shape Memory Behavior Based on Shape Memory Polymer Composites

为了解决当前大多形状记忆聚合物仅能实现单向形状记忆效应的难题,将TDE-86环氧树脂改性的氢化双酚A型形状记忆环氧树脂和以聚丁二烯为软段的聚氨酯弹性体相结合,制备了一种具备层合结构的形状记忆聚合物复合材料。该复合材料通过形状记忆环氧树脂产生的回复力与预拉伸聚氨酯弹性体产生的收缩力之间的平衡从而实现无应力下的双向形状记忆行为,即在90~110℃温度范围内,加热弯曲而冷却反向弯曲。结果表明:聚氨酯弹性体预拉伸量越大,材料在整个温度范围内的弯曲程度也越大;当回复温度在形状记忆环氧树脂玻璃化温度及以上时,材料回复程度较大;增加聚氨酯弹性体厚度会增大材料初始的弯曲程度,但会减小材料在双向形状记忆过程中的变形和回复程度。

In order to solve the unidirectional shape memory effect problem of most current shape memory polymers,a shape memory polymer composite with laminated structure is prepared by combining TDE-86 epoxy resin modified hydrogenated bisphenol A epoxy resin and polyurethane elastomer with polybutadiene as soft segment.The composite exhibits two-way shape memory behavior under stress-free condition because of the balance between the restoring force generated by the shape memory epoxy resin and the contraction force generated by the prestretched polyurethane elastomer.It demonstrates reverse bending when heated and cooled in the temperature range of 90~110℃.The results show that the greater the pre-stretched strain of the polyurethane elastomer,the larger the degree of bending in the entire temperature range.When the recovery temperature is at or above the glass transition temperature of the shape memory epoxy resin,the degree of recovery is greater.The thickness of the elastomer will increase the initial degree of bending but reduce the degree of deformation and recovery during the two-way shape memory process.