Studies on Control of the Microvoids Fixed in Non-eguilibrium Glassy State

点击翻译按钮获取中文摘要

In this study, we tried to clarify the relationship between the high-ordered structures of polymeric membranes and the gas transport properties in order to establish the control of the microvoids. At first, the gas sorption properties of polymeric membranes whose unrelaxd volume was varied by conditioning with CO_2 at various pressures, were studied. The increase in the amount of sorption was observed, it can be said that the unrelaxd volume increased with the conditioning pressure. The CO_2-conditioning was carried out, ^<129>XeNMR chemical shifts of the Xe in the conditioned samples showed up-field shift and their peak widths became narrow. Next, we prepared the alicyclic and aromatic polyimides with rigid side chain to discuss the effect of the side chain on gas transport properties and molecular structure, as an additive factor. It was concluded that the rigidity and straightforwardness of the main chain was the very important factor to control the gas permeability. The effect of m … More iscibility on gas transport properties of the rodlike polyimide (BP) /semi-flexible polyimide blend membranes were studied. The permeability coefficients of all the blend membranes were larger than those expected from the semilogarithmic additivity rule. The same results were obtained for poly (methyl methacrylate) /poly (stirene-co-acrylonitrile) blend system. Furthermore, we studied the gas transport properties of some crystalline polymers, because the crystal could be seen one of the completely controlled microvoids. In the case of poly-4-methylpentene-1, the some gases permeate in the crystalline phase whose specific volume is larger than that of the amorphous phase. The obtained dual-sorption parameter for the annealed syndiotactic polystirene cast membrane was lowered by the increase of crystallinity, indicating the sorption site formed by the adsorption of the solvent. The complex formation of the syndiotactic polystirene with some aromatic solvents were different among them from viwpoints of the sorption amounts, thermal stability, and so on. From these study, the Less