Formation of Gas Permeable Channel through the Phase Separation of Polydimethylsiloxane Graft Copolymers.

In order to establish the principle to precisely control the gas permeability and permselectivityby designing the structure of polymers in the solid statethree approaches were attempted.Gas permeation channnel could be prepared by taking advantagemicto-phase sparation ofhydrophilic and hydrophobic graft copolyners prepared from macromers.Cocomplexes were introduced by reacting with bromomathyl groups in polymer side chain to增强the选择在permeation.它也可以找到多面综合选择based graft copolymers could effectvely增强both permeability and permselectivity of oxygen gas关于nitrogen gas. This principle应用于增强the permeability and permselectivity ofoxygen permeation through the commercialized perydimethylsiloxan -b-polycarbonate oxygen separationfilm.meanwhile,factors controlling the permeation of gases through polymer films进行了投资elucidated by invesitigating the glass transition temperature，diffusion coefficient and relaxation phenomena in the permeationmobility of side chains of polymer is playing essential roles in permeation. The mobility of side chains of polymer is playing essential roles in permeationside chains可以预先控制introducing siloxane spacers between polymer main chainThe number and The type of siloxane linkage have big effect on The property of Thepolymers. For instance，one siloxane linkage reduce the glass transition temperature by 100 C and permeability coefficient30 times. According to this principle，这应该是polynorbornenes with oligodimethylsiloxane side chains were quite goodmaterials for oxygen selectively permeable membrane materials。

In order to establish the principle to precisely control the gas permeability and permselectivity, by designing the structure of polymers in the solid state, three approaches were attempted.Gas permeation channnel could be prepared by taking advantage of micto-phase sparation ofhydrophilic and hydrophobic graft copolyners prepared from macromers. Cocomplexes were introduced by reacting with bromomathyl groups in polymer side chain to enhance the selectivity in permeation. It was also found that surface accumulation of polydimethylsiloxane based graft copolymers could effectvely enhance both permeability and permselectivity of oxygen gas over nitrogen gas. This principle was applied to enhance the permeability and permselectivity of oxygen permeation through the commercialized polydimethylsiloxane-b-polycarbonate oxygen separation film.Meanwhile, factors controlling the permeation of gases through polymer films were investigated. It was elucidated, by invesitigating the glass transition temperature, diffusion coefficient and relaxation phenomena in the permeation, that mobility of side chains of polymer is playing essential roles in permeation. The mobility of side chains can be precisely controlled by introducing siloxane spacers between polymer main chain and side chains. The number and the type of siloxane linkage have big effect on the property of the polymers. For instance, one siloxane linkage reduce the glass transition temperature by 100゜C and permeability coefficient was increased by 30 times. According to this principle, it could be shown that polynorbornenes with oligodimethylsiloxane side chains were quite good materials for oxygen selectively permeable membrane materials.