| Research Abstract |
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.
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