苯胺分散聚合中稳定剂PVP-K90的稳定机理

Stabilizing Mechanism of PVP-K90 in Dispersion Polymerization of Aniline

通过分散聚合,在聚酰亚胺(PI)薄膜表面原位沉积聚苯胺(PANI)制备聚苯胺-聚酰亚胺-聚苯胺(PANI-PI-PANI)复合膜。考察了苯胺分散聚合中,不同空间稳定剂的稳定效果(不同分子量的大分子稳定剂PVP及小分子稳定剂CTAB、Tween-20),初步探讨了大分子稳定剂PVP-K90的稳定机理。实验表明,高分子量PVP-K90可稳定PANI良好成膜,且紫外和红外光谱分析证实PANI膜为掺杂态PANI,膜中不含有稳定剂PVP-K90。低分子量的PVP-K30和两亲性小分子稳定剂不能良好地稳定PANI成膜,稳定作用较差。PVP-K90的稳定作用不仅依据亲水-疏水相互作用和表面能的减少,还可能与高分子量PVP的长链分子结构及与水和苯胺的特殊相互作用有关,可用齐聚物沉淀成核机理解释。

Polyaniline-polyimide-polyaniline（PANI-PI-PANI） composite films were insitu deposited on PI film matrix in dispersion polymerization.PVP-K90,PVPK30,CTAB and Tween-20 were used as steric stabilizer and the stable effect of them on the morphology of the composite films were studied.When PVP-K90 was used as steric stabilizer,high quality composite films could be prepared.The UV and IR spectra confirmed that the surface layers of composite films were composed of HCl-doped PANI and the composite films did not contain PVP-K90.When PVP-K30、 CTAB and Tween-20 were used respectively as steric stabilizer,the composite films were weak in morphology.It showed that the good stable effect of PVP-K90 was not only related to hydrophilic-hydrophobic interaction and surface energy reduce,but also related to the maromolecular structure and the special interaction of PVP-K90,water and aniline,it could be explained by mechanism of oligomer deposited to nucleus.