Novel organosilicon‐containing polymers for an oxygen permselective membrane

Abstract

Synthesis and gas permeation measurements of several types of polymers from methylstyrene derivatives containing mono-and bis(trialkylsily1) group(@ were carried out. Upon radical homoand co-polymerization of silicon-containing monomers high-molecular-weight polymers were obtained. Results from gas permeation measurements showed that these types of siliconcontaining polymers exhibit fairly high oxygen permselectivity (ratio of oxygen and nitrogen permeation coefficients Po,/PN2 = 3,l -4,6), keeping the oxygen permeation coefficient (PoJ in the range of between 1.4and 4 3lo-' cm3 (STP)cm . cm-' * s-' * cmHg -'. From time lag measurements, it was found that permeation coefficients are dependent on the solubility of gases in the membranes rather than on diffusivity. Actually, the oxygen solubility coefficients increase with increasing silicon content in the polymers. Permselectivity of oxygen against nitrogen is governed by polymer constitution rather than by silicon content.

Syntheses and gas-transport properties of alkylsilane-modified SBS membranes

“…When the silylation occurs on all double bonds of the polythat necessitates severe reaction conditions. 9,10 (The SBS with vinyl content lower than 10% espemer, their elastomeric nature is almost totally lost. However, the selective hydrosilylation of the cially required reaction temperature higher than 80 and a time longer than 1 day to achieve comdouble bonds in the side chains of SBS was accomplished without gelation under mild conditions plete hydrosilylation on the pendant vinyl groups.…”

Gas permeation properties of poly(silamine) membrane

“…The gas permeability was measured using the vacuum method [17]. The permeability coefficient (P) was determined from the slope of the time-pressure curve at the steady state.…”

“…Contrary to the poly(dimethylsiloxane) membrane, the oxygen permeations in poly(styrene) possessing an organosilicon moiety are governed not by diffusion but by the solubility factor. Actually, with increasing silicon content in the polymer, the oxygen solubility coefficient increases [17]. This is interpreted by the affinity between oxygen molecules and the silicon atom in the polymer, because of the Lewis acidity of the Si atom due to the empty d-orbital.…”

Synthesis of Novel Organometal-Containing Polymers and Their Properties as Electron-Beam Resist Materials.

“…Methods for the syntheses and polymerizations of organometal-containing monomers and purification of other materials were described in our previous papers [4,5].…”