GAS SORPTION, DIFFUSION AND PERMEATION OF ORDERED POLYMERIC MEMBRANES

• 来源期刊: 高分子科学（英文版）
• 年，卷（期）: 2000,（4）
• 页码范围: 301-307
• 页数: 7页
• 语种: 英文

摘要

He, CO2, O2, N2, CH4, C3H8, and t-C4H10 gas permeability coefficients and diffusion coefficients ofpoly(4-methyl pentene-1) (PMP) with various degrees of crystallization were plotted against the degree of crystallization. The plot demonstrated a linear relationship. The gas permeability coefficient and diffusion coefficient of pure amorphous and pure crystalline PMPs were evaluated by a linear extrapolation to zero and 100% crystallinity, respectively. The relationship between the diffusion coefficient of crystalline parts of PMP and the kinetic diameter of penetrant gases was discussed.Syndiotactic polystyrene (SPS) could exist as δ form crystals complexed with organic solvents such as benzene, toluene,xylene, and ethylbenzene. The mesophase of SPS is prepared by annealing the δ form of crystalline complexes at a certain temperature for 1 h. The desorption of solvent during annealing almost does not result in changes of both the conformation of backbone chains and the crystal lattice. We could prepare the mesophase containing molecular cavities with the size and shape of the organic solvent molecules. The mesophase could sorb the same solvent after the manner of Langmuir sorption at low vapor pressure range while this would not be the case for solvents of different size and shape. This suggests a molecular recognition of organic solvent, and mesophase SPS might be useful for separation membrane and adsorptive material.