300072, People's Republic of China
SYNOPSIS
Several sulfolanes such as 3-methylsulfolane, sulfolane, and 3-sulfolene were tested as modifiers in poly(trimethylsilylmethy1 methacrylate) (PTMSMMA) and poly(trimethylsily1 propyne) (PMSP) to improve the selectivity of CO,. The gas permeabilities for the PTMSMMA-blend membranes containing high 3-methylsulfolane content were determined on a nonvacuum system in which the membranes started to be measured at their steady states at 3OOC; those for all the other membranes were determined in a vacuum system in which those membranes were measured after they reached their unsteady states at 30OC. The PTMSMMA-blend membrane containing 40% 3-methylsulfolane was found to give the best separation of CO, under the conditions in this study compared to all the PTMSMMA-blend membranes and the others prepared in our work; its ideal separation factors for CO, over N2 were above 40 and its permeability coefficients of CO, increased to above 250 Barrer. The modifications of PMSP membranes by impregnating with sulfolane and blending with sulfolene were found to be effective in improving the selectivity for CO, over N, for the PMSP membrane. The ideal separation factors for CO, over N, for the modified PMSP membranes impregnated with 30% sulfolane and blended with 25% 3sulfolene were improved to above 10 and 13, respectively.