Studies on Preparation of Polymer Membranes for Removal of Volatile Organic Compounds and Analysis of Membrane Characteristics

以甲基丙烯酸烷基酯和二甲基硅氧烷大分子单体(DMS)为原料，合成了三种接枝共聚物。由甲基丙烯酸甲酯(MMA)和二甲基甲基丙烯酸二甲酯(PMMA-g-PDMS)制备的膜(DMS含量为65mol%)对稀苯水溶液在渗透汽化过程中表现出较高的苯渗透选择性。为了改善高选择性苯膜，以全氟烷基丙烯酸酯和DMS为原料合成了接枝共聚物(PFA-g-PDMS)，并在PMMS-g-PDMS(DMS：65wt%)浇铸液中加入PFA-g-PDMS制备了PFA-g-PDMS/PMMA-g-PDMS膜。PFA-g-PDMS/PMMA-g-PDMS膜的表面疏水性增强，空气侧表面疏水。为了制备更高的苯膜选择性，在PMMA-g-PDMS(DMS：65wt%)铸膜液中加入对苯具有高亲和力的叔丁基[4]杯[4]芳烃。CA/PMMA-g-PDMS膜的渗透速率和苯选择性均随CA含量的增加而增加。在PMMA-g-PDMS中加入CA可以改善膜的性能，这主要是由于CA主要存在于微相分离结构的连续的PDMS相中。

Three kinds of graft copolymers were synthesized from alkylmethacrylate and dimethylsiloxane macromonomer (DMS). A membrane (DMS content 65mol%) prepared from methylmethacrylate (MMA) and DMS (PMMA-g-PDMS) showed high benzene permselectivity for an aqueous solution of dilute benzene during pervaporation. In order to improve higher benzene permselective membranes, a graft copolymer (PFA-g-PDMS) as polymer additive was synthesized from perfluoroalkyl acrylate and DMS, and PFA-g-PDMS / PMMA-g-PDMS membranes added PFA-g-PDMS to a casting solution of PMMS-g-PDMS (DMS: 65wt %) were prepared. The surface of these membranes became more hydrophobic, and consequently, the surface of the air-side of PFA-g-PDMS / PMMA-g-PDMS membranes was water-repellent. In order to prepare much more high benzene permselective membranes, tert-butyl [4]calixarene, which has high affinity for benzene, was added to a casting solution of PMMA-g-PDMS (DMS: 65wt %). Both permeation rate and benzene permselectivity of CA / PMMA-g-PDMS membranes increased with increasing CA content. Their improvement of the membrane performance with the addition of CA to PMMA-g-PDMS could be attributed to the fact that CA mainly existed in a continuous PDMS phase of the microphase separated structure.