Polytrimethylsylylpropyne Gas Separation Membranes Modified by Radiochemical Grafting of Divinylbenzene

A radiochemical method was employed to obtain poly(1-trimethylsilyl-1-propyne)(PTMSP)-divinylbenzene (DVB) grafted films. DVB monomer vapors were absorbed by the PTMSP, and the grafting reaction was thereafter accomplished by {sup 60}Co {gamma}-irradiation in a nitrogen atmosphere. The films so obtained were tested for nitrogen-oxygen separation. The performances of the membranes were studied as functions of time and percent of grafting. The DVB-grafted membranes show an increased selectivity factor and stability with time. The experimental data and some SEM observations confirm the presence of large voids in the PTMSP matrix. These voids are responsible for permeability changes during operation and disappear after the grafting procedure. 8 refs., 5 figs.