超支化共聚聚酰亚胺与氧化锌粒子复合薄膜的制备与性能研究

On preparation and properties of hyperbranched co-polyimide/ZnO composite film

通过3种单体共聚合成出了超支化共聚聚酰胺酸(co-HBPAA),随后与ZnCl _2溶液进行离子交换,再进行热处理,形成co-HBPAA的亚胺化和ZnO粒子,最后得到了超支化共聚聚酰亚胺/氧化锌(co-HBPI/ZnO)复合薄膜。SEM图像表明,ZnO粒子被成功地引入到HBPI的表面,并且分散比较均匀,没有发生明显的团聚;拉力试验表明,相比纯HBPI膜,复合薄膜的力学性能得到了一定的提升;热重曲线表明,热性能亦有了提高;同时,通过ZnO粒子的引入,薄膜的接触角从101.5°减少到79.7°,显著地从疏水薄膜变成亲水薄膜;光催化实验中,亚甲基蓝溶液颜色逐渐变浅,溶液的紫外吸收峰也在逐渐下降,说明杂化膜分解了亚甲基蓝,起到了一定的光催化作用。

The hyperbranched polyamic acid （PAA） was synthesized through a copolymerization or three monomers. Then the film was immersed info ZnCl2 solution. After a succeeding heat treatment , the imidization of PAA and for mation of ZnO nanoparticles can be simultaneously achieved to obtain the hyperbranched co polyimide （co -HBPI）/ZnO composite rilm. The SEM images manifested that the ZnO particles were successrully immobilized on the surrace or co HBPI, and dispersed homogeneously without obvious aggregation. The tensile tests indicated that the mechanical properties or composite rilm had some improvement compared with the pure ril m. The TG curves showed that the thermal perrormance or composite film had aslight increasing. In the meantime, after addition of ZnO particles, the co HBPI/ZnO composite exhibited decreased contact angle （CA） value from 101.5° to 79.7° , which means that HBPI film turns from hydrophobicity （CA〉 90° ） to hydrophilicity （CA〈 90°）. The photocatalytic experiments showed the solutions or methylene blue raded gradually and the ultraviolet absorption peaks or them were also decreased. It indicated the composite rilm really accelerated the photocatalysis or methylene blue.