异氰酸酯指数及固化温度对聚酰亚胺泡沫结构与性能的影响  

Influence of Isocyanate Index and Curing Temperature on the Structure and Properties of Polyimide Foams

作　　者：王贯春[1] 苗宗南 倪龙 周生态 梁梅[2] 邹华维[2] 邱绍宇[1] GuanchunWang;Zongnan Miao;Long Ni;Shengtai Zhou;Mei Liang;Huawei Zou;Shaoyu Qiu(Science and Technology on Reactor Fuel and Materials Laboratory,Nuclear Power Institute of China,Chengdu 610041,China;State Key Laboratory of Polymer Materials Engineering,Polymer Research Institute of Sichuan University,Chengdu 610065,China)

机构地区：[1]中国核动力研究设计院反应堆燃料及材料重点实验室,四川成都610041 [2]四川大学高分子研究所高分子材料工程国家重点实验室,四川成都610065

出　　处：《高分子材料科学与工程》2022年第4期152-158,共7页Polymer Materials Science & Engineering

基　　金：中国核动力研究设计院原创基金;先进核电保温产品标准化体系。

摘　　要：以均苯四甲酸二酐、3,3’,4,4’-联苯四甲酸二酐和多异氰酸酯为主要原料,采用一步法自由发泡方式成功制备出性能优异的轻质异氰酸酯基聚酰亚胺泡沫(IBPIF),并研究了异氰酸酯指数(R)及固化温度对IBPIF性能的影响。轻质IBPIF的密度在10~25 kg/m3之间,泡沫密度随着R和固化温度的升高而降低。扫描电镜结果表明,随着R值的提高,IBPIF的泡孔形貌变得更加规整,其平均孔径在0.30~0.55 mm之间,且随着R和固化温度的提高,其平均孔径均呈上升趋势。采用热重分析和极限氧指数评价泡沫的热稳定性和阻燃性能,泡沫初始热分解温度为234~272℃,800℃热残重为45%~51%,具有良好的热稳定性,提高固化温度有助于酰亚胺化过程的进行,从而提升材料的耐热性能。泡沫的热稳定性和阻燃性能随着R值的增加(0.9~1.2)呈先上升后降低的趋势。当固化温度为250℃,IBPIF的极限氧指数最高可达47.5%,表现出优异的阻燃性能。R值为1.0,固化温度为250℃时,IBPIF的综合性能最佳。该方法制备的聚酰亚胺泡沫有望在航空航天领域获得重要应用。Lightweight isocyanate-based polyimide foam(IBPIF)with excellent properties was successfully prepared by a one-step free foaming process using pyromellitic dianhydride,3,3′,4,4′-biphenyltetracarboxylic dianhydride and polyisocyanates as raw material,and the effects of isocyanate index(R)and curing temperature on the performance of IBPIF were investigated.The density of IBPIF ranges from 10~25 kg/m3 and the foam density decreases with increasing R and curing temperature.SEM results show that the pore morphologies of IBPIF become more regular as R increases,with an average pore size between 0.30~0.55 mm,and the average pore size tends to increase with increasing the R and curing temperature.The thermal stability and flame retardancy of IBPIF were evaluated by thermal mass loss analysis and limiting oxygen index test.The initial thermal decomposition temperature of the foam is 234~272℃and the thermal residual mass at 800℃falls within 45%~51%.The foam possesses a good thermal stability,while increasing the curing temperature helps the imidization process to take place,thu enhancing the heat resistance of the material.The thermal stability and flame retardant properties of the foam tends to increase and then decrease with increasing R(0.9~1.2).When the curing temperature is increased to 250℃,the limiting oxygen index(LOI)of IBPIF reaches as high as 47.5%,showing excellent flame resistance.The best overall performance of the IBPIF is got at an R of 1.0 and a curing temperature of 250℃.The prepared PIFs are expected to achieve important applications in the aerospace sector.

关 键 词：聚酰亚胺泡沫 异氰酸酯指数 固化温度 阻燃 

分 类 号：TQ328[化学工程—合成树脂塑料工业]