将静电纺丝得到的聚酰胺酸(PAAs)、聚四氟乙烯-聚酰胺酰亚胺(PTFE-PAI)纳米纤维通过均质乳化、冷冻干燥、高温烧结过程,制备出结构良好、性能优异的PTFE-PAI/聚酰亚胺(PI)复合纳米纤维气凝胶,有效地减少了PTFE-PAI纳米纤维气凝胶烧结过程中的收缩率。利用扫描电镜、热重分析仪、滤料综合性能试验台探究了不同纤维混合比例、纤维含量、烧结温度对气凝胶结构性能的影响。结果表明,当PAAs纤维与PTFE-PAI纤维质量比为5∶5、烧结温度为350～400℃、纤维固含量在1%～1.5%时,得到的PTFE-PAI/PI复合纳米纤维气凝胶具有较高的孔隙率(96.05％～98.95％)、良好的热稳定性(505℃以上)和过滤效率,显示了其在过滤领域的应用潜力。
The polyamic acid (PAAs) and polytetrafluoroethylene-polyamideimide (PTFE-PAI) nanofibers obtained by electrostatic spinning were processed through homogenization,freeze-drying,and high-temperature sintering.Finally,the PTFE-PAI/PI composite nanofiber aerogel with good structure and excellent performance was prepared,which would effectively reduce the shrinkage during the sintering process of the simple PTFE-PAI nanofiber aerogel.The effect of the fiber mixing ratio,fiber content and sintering temperature on the structure of the aerogel were characterized by scanning electron microscope,thermogravimetric analyzer,and filtration material comprehensive performance test bench.The results showed that:the as-prepared PTFE-PAI/PI aerogel possessed high porosity (96.05%～98.95%),thermal stability (above 505℃) and good filtration efficiency,when the ratio of PAAs∶PTFE-PAI was 5∶5,the sintering temperature between 350～400℃,fiber solid content was 1%～1.5%,which indicated its potential in the application of filtration.
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