杂萘联苯聚醚砜酮类材料成膜动力学研究(Ⅰ)添加剂对PPESK凝胶动力学的影响

以杂萘联苯聚醚砜酮(PPESK)/NMP为铸膜液体系,进行成膜过程凝胶动力学研究.发现凝胶动力学曲线(X2~t)不是由单一直线组成的,而是由三段对应着不同膜结构的直线组成.考察了不同添加剂对PPESK-NMP体系凝胶速度的影响.结果表明,亲水性强的添加剂,可提高铸膜液体系的亲水性,从而加快溶剂、非溶剂的传质速率,凝胶速度加快,膜的水通量增加.使铸膜液黏度增加的添加剂,使非溶剂扩散系数降低,凝胶速度减慢,膜的水通量减少.丙二酸添加剂增大了铸膜液的亲水性,使铸膜液的凝胶速度增大.吐温添加剂既增加了铸膜液的亲水性又增加了铸膜液的黏度,凝胶速度也先变小后变大.PEG添加剂虽然增大了铸膜液体系的亲水性,但同时也提高了铸膜液的黏度,凝胶速度的变化不大.

Gelation kinetics of phenodiazine polyether- suifone - ketone membrane formation via phase inversion ( Ⅰ ) Effect of additives on gelation rate of PPESK membrane formation

The gelation kinetics of poly(phthalazine ether sulfone ketone)(PPESK) membrane formation via phase inversion was investigated.It is found that three different linear correlations between the value of X2 and gelation time t correspond to the morphology evolution of the membrane.The water flux of membrane increases with the rise of gelation rate by introducing hydrophilic additives.The additives which can enhance the viscosity of casting solution will depress the solvent diffusion coeficient,so that the gelation rate and water flux will be decreased.The additive of propane diacid is shown to enhance the hydrophilicity of the cast solution,thereby,the gelation rate of the cast film is accelerated.When adding tween,not only the viscosity but also hydrophilicity of the cast solution are increased.Therefore,the gelation rate is enhanced at first and then decreased.PEG is shown to be able to enhance both hydrophilicity and viscosity of the cast solution.As a result,the gelation rate has no obvious change.