嵌段共聚物热分解制备多孔聚酰亚胺微球

Preparation of Porous Polyimide Spheres by Thermolysis of Block Copolymers

在非水乳液体系中,以聚醚胺为热不稳定嵌段,均苯四甲酸二酐和4,4’-二氨基二苯醚为单体进行缩聚反应,所得产物经两步亚胺化形成具有微相分离结构的聚酰亚胺嵌段共聚物微球,其中聚酰亚胺为连续相,聚醚胺为分散相。在减压条件下对聚醚胺进行热氧分解,制备具有大孔结构的聚酰亚胺微球。产物的结构和形貌分别采用红外、热重、扫描电镜等手段进行表征。结果表明,减压条件下聚醚胺在260℃分解10h即可除去,真空度为-0.03～-0.06MPa时可以得到孔径在几百纳米的多孔聚酰亚胺微球,相同分解条件下相对分子质量为2 070的聚醚胺比相对分子质量为1 000的聚醚胺得到的孔结构更大。

In non-aqueous emulsion system, triblock copolymer microspheres were prepared by polycondensation of J-2070/J-1000 as thermally labile block and pyromellitic dianhydrede/4, 4＇-oxydianiline as monomers. The microspheres were consisted of thermally labile block as the dispersed phase and polyimide as the continuous phase. The macroporous polyimide spheres were obtained by pyrolyzing the copolymers spheres under vacuum. The morphologies and properties of porous polyimide spheres were measured by SEM, FTIR and TGA. The results show that J- 2070/J-1000 was totally removed by heating copolymer spheres to 260~C for 10 h in vacuum. When the vacuum was-0.03～-0. 06 MPa during degradation process, the pore size was 300～ 500 nm. The J-2070 was more suitable as the thermally labile block than J-1000.