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在Span85/N,N-二甲基甲酰胺/液体石蜡稳定反相非水乳液体系中,以均苯四甲酸酐和4,4’-二氨基二苯醚为单体,选用甲醇、二硫化碳作为致孔剂,制备多孔聚酰亚胺(PI)微球.通过SEM、量子化学模拟、粒径测试等手段考察致孔剂种类、致孔剂用量、吡啶/酸酐滴加速度及反应温度和单体浓度对致孔的影响.结果表明,选用二硫化碳、甲醇为致孔剂时所制得的微球形貌良好,但CS2为致孔剂时,所得到的微球孔道很少;而甲醇为致孔剂时,则得到了孔道明显的多孔PI微球.致孔的最佳条件为反应温度20℃,单体浓度10%,吡啶/酸酐滴加速度0.5 s/滴时,才可得到的形貌良好、分布均一的多孔PI微球.而且随着甲醇/液体石蜡的体积比增加,多孔PI微球比表面积也随着增大,最大可达29.38 m2/g.所得产物粒径分布在20~30μm之间,热稳定性良好,其起始热分解温度为517℃.
In Span85 / N, N-dimethylformamide / liquid paraffin stable reversed-phase non-aqueous emulsion system, with pyromellitic dianhydride and 4,4’-diaminodiphenyl ether as monomer, use of methanol, carbon disulfide as Porous polyimide (PI) microspheres were prepared by means of SEM, quantum chemical simulation and particle size test.The effects of porogen species, porogen concentration, pyridine / acid anhydride addition rate, reaction temperature and monomer The results showed that the morphology of microspheres prepared by using carbon disulfide and methanol as porogen is good, but when CS2 is a porogen, Pore, the porous PI microspheres with obvious pores were obtained.The optimum conditions for the pore formation were as follows: reaction temperature 20 ℃, monomer concentration 10%, pyridine / anhydride dropping rate 0.5 s / Good and uniform distribution of porous PI microspheres.With the increase of the volume ratio of methanol / liquid paraffin, the specific surface area of porous PI microspheres also increased with the maximum up to 29.38 m2 / g.The particle size distribution of the obtained products was in the range of 20 ~ 30μm, thermal stability is good, the initial thermal decomposition temperature is 517 ℃.