以聚丙烯腈(PAN)为成膜载体,由聚四氟乙烯(PTFE)分散乳液通过干湿法纺丝制得PTFE/PAN共混中空纤维膜。利用红外光谱(FT—IR)研究了烧结前后中空纤维膜的化学变化,热失重(TGA)分析了中空纤维膜的热稳定性,并采用场发射扫描电镜(FESEM)观察了不同烧结温度的中空纤维膜形貌。结果表明:在预氧化烧结过程中PAN发生了环化反应,生成耐热的梯形结构,提高了中空纤维膜的耐热性;随着烧结温度的升高,生成的点纤结构尺寸明显增加,中空纤维膜的力学强度显著提高。
Poly(tetrafluoroethylene)(PTFE)/poly(acrylonitrile)(PAN) blend hollow fiber membranes were prepared from the blends of PTFE emulsion and PAN through dry-wet spinning method. The chemical constitutions of hollow fiber membranes before and after sintering were investigated with FT-IR. Meanwhile, TGA was utilized to analyse the thermal stability of hollow fiber membranes. The structure and morphology of hollow fiber membranes at different sintering temperatures were characterized by field emission scanning electronic microscopy (FESEM). Results show that cyclization reaction occurs during the pre oxidation and sintering process in PAN. Moreover, the trapezoidal structure improves the thermal resistance of hollow fiber membranes; the size of node-fibril structure increases obviously as the raising of sintering temperature, which leads to the enhancement of mem- brane mechanical strength.