基于Flory-Huggins高分子溶液理论,计算了聚砜(PSF)-二甲基乙酰胺(DMAc)-非溶剂铸膜体系的三元相图,其中二甲基乙酰胺(DMAc)为溶剂,水、甘油、乙醇和正己烷为非溶剂,通过相图分析了不同非溶剂对凝胶时间的影响,同时考虑了扩散的影响.根据计算结果得到如下结论:双节线或旋节线与聚合物-溶剂轴的距离越近,凝胶时间越短;非溶剂与溶剂的相互扩散速度越快,凝胶时间越短;联结线的斜率越小,即分相时聚合物稀相中非溶剂的量越少,凝胶时间越短.
The ternary diagrams of polysulfone(PSF - N, N - dimethylacetamide(DMAc) - nonsolvent were calculated based on Flory- Huggins' s polymer solution theory using DMAc as solvent and water, glycerol, ethanol and n -hexane as nonsolvent. The effect of nonsolvents on gelating speed was analysised by means of the ternary phase diagrams considering the effect of diffusion. It concluded that the closer the distance beteen binodal or spinodal and the polymer- solvent axis the shorter the gelating time; the quicker the mutual diffusion speed of nonsolvent and solvent the shorter the gelating time; the smaller the slope of tieline, i. e. the less the nonsolvent in the polymer-lean phase while demixing happen, the shorter the gelating time.