聚降冰片烯/微晶蜡复合材料形状记忆性能的研究

Study on Shape Memory Properties of Polynorbornene/Microcrystalline Wax Materials

以聚降冰片烯树脂(PNB)为基体,通过改变微晶蜡(MW)的填充含量制备PNB/MW复合材料,利用偏光显微镜、示差扫描量热仪(DSC)、动态力学分析(DMA)与万能电子拉伸试验机等测试手段,研究PNB/MW两相结构与基本性能,同时采用DMA-Q800测试复合材料的二重形状记忆及可逆塑性形状记忆性能,并与填充同等含量的环保芳烃油(TDAE)的PNB进行对比.结果表明,微晶蜡可以调节PNB材料的玻璃化转变温度接近于室温,有利于室温下的可逆塑性形状记忆,且其无污染,可以代替TDAE增塑油改善PNB的加工;PNB/MW复合材料物理机械性能良好,200%以上的断裂伸长率提供了较大的形变范围,有利于材料的变形与恢复;微晶蜡较宽的固-液转变可以作为可逆相,使恢复过程温和可控;固态微晶蜡阻碍PNB链段运动,提高可逆塑性的形状固定率,微晶蜡含量越多,固定效果越明显,PNB/MW50展现出优异的二重及可逆塑性形状记忆性能.

Polynorbornene(PNB)is a kind of smart material with excellent shape memory performance.The appearance of PNB is powder,so it can only be processed by adding plasticizing oil.In order to broaden its processing method and avoid environmental pollution caused by aromatic oils containing benzene,microcrystalline wax(MW)can be used as a better choice for plasticizing oil.Therefore,PNB/MW materials were prepared by using PNB as the matrix and adding microcrystalline wax with different contents.The basic properties of PNB/MW materials were studied by Shore D hardness tester,polarizing microscope,differential scanning calorimeter(DSC),universal electronic tensile testing machine and dynamic mechanical analysis(DMA).The dual-shape memory and reversible plasticity shape memory properties of PNB/MW materials were studied by DMA-Q800.The results showed that the glass transition temperature(Tg)of PNB is adjusted to near room temperature by microcrystalline wax,which was beneficial to the reversible plasticity deformation.So MW could replace treated distillate aromatic extract(TDAE)for the processing of PNB because of its non-pollution.The elongation at break of PNB/MW materials was more than 200%,and the tensile strength was high.The high elongation at break was beneficial to the deformation and recovery of the shape memory.In addition,the wide solid-liquid transition of microcrystalline wax also played the role of reversible phase,which made the recovery process controllable.The movement of PNB chain segment was limited by solid microcrystalline wax,which contributed to the fixation process of reversible plasticity shape memory.It was concluded that PNB/MW50 had excellent dual-shape memory and reversible plasticity shape memory performance.