摘要
气凝胶纤维具有良好的柔韧性,其织物在可穿戴保温隔热领域受到了人们高度的关注。聚对苯二甲酰对苯二胺(PPTA)具有优异的耐热性、耐化学品腐蚀等性能,是制备气凝胶纤维的理想材料。然而,目前利用PPTA纤维(对位芳纶)的纳米纤维分散液制备气凝胶纤维的过程复杂、耗时且成本高,因此本工作通过合成具有良好可加工性的PPTA溶液,利用湿法纺丝和冷冻干燥工艺制备PPTA气凝胶纤维,极大地简化了工艺流程。实验分析表明,通过改变PPTA溶液的浓度可以有效地控制气凝胶纤维的孔结构及机械强度。当PPTA溶液的质量分数为2%时,制得的气凝胶纤维的孔隙率高达94.5%,断裂强度可达7.8 MPa;除此之外,该气凝胶纤维还具有高的比表面积(291 m2/g)和低的热导率,其织物的热导率为29.65 mW/(m·K)。当PPTA溶液的质量分数为5%时,气凝胶纤维的断裂强度高达20.5 MPa。本工作中所制备的气凝胶纤维具有极高的孔隙率、超低的密度和热导率以及良好的力学性能,为新一代保温隔热纺织品的设计和制造开辟了新的途径。
Aerogel fibers have attracted tremendous attention in the field of wearable thermal insulation because of its good flexibility.Poly(p-phenylene terephthalamide)(PPTA)has excellent heat resistance,chemical resistance and other properties,and is an ideal material for preparing aerogel fibers.However,the process of preparing aerogel fibers from aramid nanofiber dispersion suffer from complex,time-consuming and costly,limiting their application in practical conditions.Here,PPTA solution with good processability was synthesized by solution polymerization at low temperature,and then the combine of wet-spinning and freeze drying was used to fabricate PPTA aerogel fibers with excellent weavability.The effects of PPTA solution concentration on the pore structure and mechanical strength of PPTA aerogel fibers were studied.The lowest thermal conductivity(29.65 mW/(m·K))was attained when the concentration of PPTA solution was 2wt%.Meanwhile,the PPTA aerogel fibers de-monstrate superior mechanical property(7.8 MPa),high specific surface area(291 m 2/g)and porosity(94.5%).When the concentration of PPTA solution increases to 5wt%,the breaking strength of the aerogel fibers can achieve 20.5 MPa.This work shows that PPTA solution prepared through the low-temperature-solution polycondensation may offer a rapid approach to achieve excellent mechanical strength,extremely high porosity,ultra-low density and thermal conductivity of PPTA aerogel fibers,allowing for cost-effective and simplified production of stronger PPTA aerogel fibers,which opens up a new way for the design and manufacture of the next generation of thermal insulation textiles.
作者
李杰
胡祖明
于俊荣
王彦
诸静
LI Jie;HU Zuming;YU Junrong;WANG Yan;ZHU Jing(School of Materials Science and Engineering,Donghua University,Shanghai 201620,China;State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University,Shanghai 201620,China)
出处
《材料导报》
EI
CSCD
北大核心
2024年第2期228-233,共6页
Materials Reports
基金
国家重点研发计划项目(2021YFB3700101)。
