反相气相色谱法可以快速、准确测定高分子与溶剂间的相互作用.利用反相气相色谱法测定了353.15~373.15K温度范围内正庚烷、噻吩、2-甲基噻吩、2,5-二甲基噻吩、乙硫醚等溶剂在聚三氟乙氧基磷腈(PTFEP)中的无限稀释活度系数和无限稀释扩散系数.计算了PTFEP对有机硫/正庚烷体系的无限稀释选择性,利用Arrhenius方程确定了上述溶剂在PTFEP中的扩散活化能和扩散常数.实验结果表明:在测定温度范围内,升高温度有利于小分子在PTFEP中的溶解和扩散.小分子在聚合物内的扩散,受分子尺寸和小分子、聚合物间相互作用的共同影响.本研究取得的参数将为渗透汽化传质模型的建立提供必要的理论基础.
Inverse gas chromatography(IGC)is a fast and reliable technique to measure the solventpolymer interplay.In this study,the infinite dilute activity coefficients and infinite dilute diffusioncoefficients of n-heptane,thiophene,2-methylthiophene,2,5-dimethylphene and ethyl sulfide in poly[bis(trifluoroethoxy)phosphazene](PTFEP)were determined in the temperature ranging from 353.15Kto373.15 K with an increment of 5K.The infinite dilute selectivites were measured from the experimental data,the pre-exponential factors and activation energy were also obtained according to Arrhenius equation.The experiment results showed that higher temperatures would accelerate the diffusion rate and also increase the sorption on membrane surface.And the diffusion through the membranes was affected by sizes of solvent molecules and the interactions between solvents and polymer.The obtained data would contribute to the study of transferring mechanism in PTFEP membranes.