形状记忆PI/ANF复合气凝胶的制备与性能

Preparation of shape memory PI/ANF composite nanofiber aerogel and its performances

为解决气凝胶的低密度带来的空间成本问题,将聚酰胺酸纳米纤维及芳纶纳米纤维通过水相分散、冷冻干燥、热亚胺化等过程制备了具有形状记忆特性的聚酰亚胺/芳纶复合纳米纤维气凝胶,并对其微观形貌、化学结构、力学性能、隔热性能和形状记忆性能进行了研究。结果表明:复合气凝胶表现为纳米纤维相互缠结的三维网络,体密度仅为0.0096 g/cm^(3),具有优异的热稳定性和隔热性能,导热系数为0.0317 W/(m·K);气凝胶表现出形状记忆特性,当温度大于140℃时,气凝胶开始从临时形状恢复至初始形状,其形状固定率和形状恢复率分别可达到84.5%和96.15%,在智能材料、高温隔热领域有广阔的前景。

In order to reduce the space cost of low-density aerogel,polyimide/aramid composite nanofiber aerogel with shape memory property was prepared following the procedures of water-phase dispersion,freeze drying and thermal im-idization.The microstructure,chemical structure,mechanical properties,thermal insulation and shape memory properties were studied.The results show that the composite aerogel is characterized by a three-dimensional network of intertangled nanofibers with a bulk density of 0.0096 g/cm^(3).The composite aerogel showes excellent ther-mal stability and thermal insulation performance,with thermal conductivity as low as 0.0317 W/(m·K).At the same time,it exhibites shape memory characteristic,its shape can transform from temporary shape to permanent shape when the temperature is above 140℃,and its shape fixation rate and shape recovery rate can reach 84.5%and 96.15%respectively,which demonstrates broad prospects in the field of intelligent materials and high temperature heat insulation.