单分散聚酰亚胺微球的形貌分析和表征

Characterization and morphology analysis of monodisperse polyimide microspheres

研以均苯四甲酸二酐(PMDA)和4,4(?)二氨基二苯醚(ODA)为单体,采用反相非水乳液法制备聚酰亚胺(PI)微球。在两相比一定时,研究了复配乳化剂的浓度对PI微球形貌及单体含量对微球粒径的影响。产物通过红外,热重(TG),扫描电镜(SEM),粒度分析手段进行表征。SEM表明:单体浓度20%,复配乳化剂含量7.88%时,得到形貌良好、呈单分散性的微球;粒度分析知单体含量越低,微球粒径越小;TG表明:PI在氮气气氛下热稳定性良好(5%热失重温度540℃)。

Polyimide(PI) microspheres was synthesized from pyromellitic dianhydride(PMDA) and 4,4'-Diaminodiphenyl ether(ODA) by the nonaqueous reverse emulsion at room temperature.The effects of different emulsifier content on the morphology of PI microspheres and monomer contents on mean diameter of microspheres were studied under the fixed ratio of two phases.The properties and the morphology of product were characterized by FTIR、TG、DSC、SEM and particles size analysis.The results showed that morphology with good shape and monodispersity could be obtained when the monomer contents was 20wt%and the mixed emulsifiers concentration was 7.88%;Particle size analytical technique shows the lower monomer contents were better when the diameter of particles was smaller.TG shows the polyimide microspheres possessed excellent thermal stability at which the 5wt%loss temperatures in N2 were 540℃.