GAS SEPARATION MEMBRANES PREPARED BY STYRENE-GRAFTED POLYTRIMETHYLSILYLPROPYNE

Poly(l-trimethylsilyl-l-propyne) (PTMSP)-styrene (St) grafted films we re obtained by a radiochemical method. St monomer vapors were absorbed by the PTMSP, and the grafting reaction was thereafter accomplished b y Co-60 gamma irradiation in a nitrogen atmosphere. The films so graft ed were tested for nitrogen-oxygen separation. The performances of the membranes were studied as functions of time and percent of grafting. The PTMSP-St grafted membranes showed an increased selectivity factor and better stability in comparison with pure PTMSP. The experimental d ata and some SEM observations confirmed that the grafting procedure ch anges the PTMSP matrix structure, filling the voids responsible for th e PTMSP permeability change with time.