Characterization for graft polymerization of alkyl methacrylate onto polydimethylsiloxane membranes by electron beam and their permselectivity for volatile organic compounds

Abstract

Polydimethylsiloxane (PDMS) membranes were improved by graft polymerization of fluoroalkyl methacrylates (FALMA) and alkyl methacrylates (AMA) by electron beam, and the effect of the solubility and diffusibility of a monomer on graft polymerization and the pervaporation through grafted membrane were investigated. The difference of the grafted amount was small for the monomers with various solubility parameters and log Pow which is the logarithm of the octanol–water partition coefficient. Compared to each other in the same group of FALMA or AMA, the sorpted and grafted amount for a monomer that has low molecular volume was high, and the sorpted and grafted amount for a monomer that has high molecular volume was low. FALMA-grafted PDMS membranes showed high separation performance compared to PDMS membranes. Among them, 2,2,3,3,3-pentafluoropropyl methacrylate grafted PDMS membrane, which had a high grafted amount, and F/Si calculated by the grafted amount had high selectivity for trichloroethylene (TCE). The FALMA-grafted PDMS membranes that had the high TCE concentrations in the sorbed solution exhibited high permselectivity for TCE. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 203–213, 2001