Fundamental Research on Structure and Permeation and Separation Characteristics of Polymer Membranes for Separation of Organic Liquid Mixtures

通过改变制膜条件，制备了具有不同化学和物理结构的壳聚糖（chito）、聚二甲基硅氧烷（PDMS）、聚[1-（三甲基硅基）-1-丙炔]（PTMSP）和甲基丙烯酸甲酯-二甲基硅氧烷（MMA-g-DMS）膜。采用有机液膜分离技术之一的渗透汽化（PV）、本课题组的新型膜分离技术的膜分离（EV）和改进EV的温差控制膜分离（TDEV），在不同的渗透条件下，研究了乙醇水溶液的渗透分离特性。在chito膜中，PV和EV都表现出水的选择性渗透，EV的选择性渗透比PV高。它们的选择性渗透显著依赖于基于氢键的chito膜的自由亲水基团的程度。PDMS膜在PV中表现出对乙醇的选择透过性，当将其用于TD时， ...更多信息 料液温度与膜环境温度差越大，乙醇选择透过率越高。在PTMSP膜中，PV和TDEV都具有与PDMS膜相同的乙醇选择透过性，但PTMSP膜的渗透速率和乙醇选择透过性均大于PDMS膜。结果表明，PTMSP膜的渗透速率随膜厚度的减小而显著增加，而乙醇的选择透过性与膜厚度无关。MMA-g-DMS共聚物膜的PV性能与共聚物中DMS单元的含量密切相关。即DMS单元含量小于36mol%的膜具有水选择透过性，大于36mol%的膜具有乙醇选择透过性。通过差示扫描量热法和透射电镜观察，揭示了MMA-g-DMS膜的选择透过性的差异，并通过理论渗透方程进行了分析。少

Chitosan (chito), poly (dimethylsiloxane) (PDMS), poly [1- (trimethylsilyl) -1-propyne] (PTMSP) and methyl methacrylate-dimethylsiloxane (MMA-g-DMS) membranes with different chemical and physical structures were prepared by changing conditions of membrane preparation. Characteristics of permeation and separation for aqueous ethanol solutions were studied by pervaporation (PV) which is one of membrane separation techniques for organic liquid mixtures, evapomeation (EV) which was developed by head investigator and coworkers, and themperature difference controlling evapomeation (TDEV) which was improved EV under various permeation conditions. In the chito membrane, both PV and EV showed water-permselectivity and the permselectivity in EV was higher than in PV.Their permselectivity significantly depended on a degree of free hydrophilic groups based on hydrogen bonds of the chito membrane. In the PDMS membrane, ethanol-permselectivity was shown in PV and when this membrane was applied to TD … More EV,ethanol-permselectivity was increased with bigger difference between the temperatures of the feed solution and membrane surroundings. In the PTMSP membrane, both PV and TDEV had ethanol-permselectivity as well as the PDMS membrane, but permeation rate and ethanol-permselectivity in the PTMSP membrane were greater than those in the PDMS membrane. It was found that the permeation rate was remarkably increased with decreasing thickness of the PTMSP membrane and ethanol-permselectivity was kept constant regardless of the membrane thickness. In PV of MMA-g-DMS membrane, the permselectivity significantly depended on the DMS unit content in the MMA-g-DMS copolymer. Namely, the membranes less than DMS unit content of 36mol% showed the waterpermselectivity and those of moer than 36mol% had the ethanol-permselectivity. These difference of the permselectivity was revealed by measurements of difference scanning calorimetry and observations of transmission electron microscope of the MMA-g-DMS membranes and furthermore analyzed by theoretical equation of the permeation. Less