Study On Synthesis Of Cyclic Trimer As Surface Modifier And Oxygen Separation Ability Of Blend Membranes

Gas permselective membrane was attracted much attention in the process of gasseparation because of its “Efficient, Saving, Environmental”. However, about40years developing history of it, just very small portion were used in industrialproduction. Low mechanical strength and poor permselective cause the biggestportion of them were useless in industry. In this research, high mechanical strengthgas separation membranes were used as base membrane and the blend membraneswere fabricated by mixing blend membrane with surface modifier. By using thismethod high mechanical strength and permselective oxygen gas permselectivemembranes were fabricated.[5-ethynyl-2-({4-[2-(methoxymethoxy)ethoxy]benzyl}oxy)-1,3-phenylene]dimethanol MEO2-p-BDHPA(M1),[5-ethynyl-2-({2-[2-(methoxymethoxy)ethoxy]benzyl}oxy)-1,3-phenylene]dimethanol MEO2-o-BDHPA(M2),(4-ethynylphenyl)trimethylsilane SPA(M3). Three kinds of new monomers were synthesized, the reacti-onconditions of monomers were discussed and the structures were confirmed by1HNMR.The polymerization and copolymerization of M1and M2are carried out u-sing the [Rh(nbd)Cl]2as a catalyst, TEA as a cocatalyst respectively. Molecul-ar weight of Poly{[5-ethynyl-2-({4-[2-(methoxymethoxy)ethoxy]benzyl}oxy)-1,3-p-henylene]dimethanol} Poly(MEO2-p-BDHPA)(P1), Poly{[5-ethynyl-2-({2-[2-(methoxymethoxy)ethoxy]benzyl}oxy)-1,3-phenylene]dimethanol} Poly(MEO2-o-BDHPA)(P2) were tested by GPC. The results shown the best [Rh(nbd)Cl]2/PEA catalyst system for this polymerization. Helical structure of the polymers was confirmedby CD-UV spectra and the reason effects of helical structure were discussed.The polymer membranes were placed under visible light irradiation for a moment,the trimer of1,3,5-trisubstituted benzene derivative T1and T2were obtained. Thepolymerization processes of the reactions were monitored by GPC and the structure ofT1and T2were conformed by1H NMR and MS.The blend membranes were fabricated by two different methods. The change ofthe structure of membrane surface was conformed by water contact angle on the membrane and the permselectivity and permeability of blend membranes were tested.The effect of membrane structure and fabricating methods on blend membranes werediscussed.