共查询到18条相似文献,搜索用时 78 毫秒
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以聚4-甲基戊烯-1(PMP)为膜材质,分别以环己烷、三氯乙烯、四氯乙烯及环己烷/三氯乙烯为溶剂,研究了这些溶液浇铸膜对O2、N2、H2及CO2等气体的透过行为。结果表明,气体的透过主要发生在PMP的无定形区域,但也在PMP的晶区进行。PMP的Ⅵ型结晶比Ⅰ型结晶具有较低的氧化透过活化能。 相似文献
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Bromo- and chloropoly-4-methylpentene-l were obtained from the macromolecular reactions of PMP with chlorine and bromine respectively. The influences of reaction conditions, the contents of bromine and chlorine in halo-PMP and the natures of bromine and chlorine themselves on the gas permeation properties were discussed. 相似文献
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4-甲基-1-戊烯(4M1P)是烯烃工业中一种重要的支链α-烯烃,它的主要用途是用于制备均聚物和共聚物。虽然绝大部分4M1P共聚物尚未进入工业化生产阶段,但由于共聚物作为一类新型的合成树脂具有突出的力学性能和光学性能,已成为国外聚烯烃领域的一个研究热点。本文阐述了4M1P与烯烃共聚反应催化剂包括Ziegler-Natta催化剂、茂金属催化剂及后过渡金属催化剂的开发研究现状;重点阐述了催化剂的结构对共聚物分子结构的影响;同时也简要介绍了二亚胺镍催化剂催化4M1P共聚反应作用机理,展望了这一领域的发展趋势。为开发高端聚烯烃新材料提供参考。 相似文献
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在聚4-甲基戊烯-1(PMP)的环已烷溶液中,加入对水有一定亲合性的第三组分环已酮作为展开助剂,研究了该三组分溶液体系的界面性质与溶液在水面上展开程度的关系。发现环已酮的加入明显降低了PMP溶液对水的界面张力,使得溶液在水面上的展开系数大为增加,得以制备厚度为10~25nm的PMP超薄膜。 相似文献
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以聚4-甲基戊烯-1(PMP)为膜材质,分别以环己烷、三氯乙烯、四氯乙烯及环已烷/三氯乙烯为溶剂,研究了这些溶液浇铸膜对O_2、N_2、H_2及CO_2等气体的透过行为。结果表明,气体的透过主要发生在PMP的无定形区域,但也在PMP的晶区进行。PMP的Ⅵ型结晶比Ⅰ型结晶具有较低的气体透过活化能。 相似文献
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Membranes for gas separation have developed significantly in the last twenty years,however,there is still a need for high temperature and chemically resistant membranes that exhibit good selectivity and gas permeability.Our study examines the fundamental properties of polyetherketone (PEK,a thermally stable and chemically resistant polymer) membranes prepared using concentrated sulphuric acid (98% H_2SO_4) as the solvent.Non-solvents used in the work included acetic acid,ethanol,methanol,glycerol,and wat... 相似文献
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By means of a vacuum time-lag method, gas transport properties of apolyimide based on 2, 2- bis (3, 4- decarboxyphenyl ) hexafluoropropane dianhydride (6FDA )and meta- phenylenediamine (mPDA ) have been measured as a function of upstream pres-sure and temperature. The results show that no gas-induced plasticization occurs for thispolyimide in the upstream pressure range from 1 atm to 20atm. The temperature depen-dence of P and D can be described by the Arrhenius equations. The activation energiesof permeation and diffusion were obtained for the gas/polymer pair studied and correlatedwith the size of penetrant gas. 相似文献
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Yoshiharu Tsujita 《高分子科学》2000,(4):301-307
He, CO_2, O_2, N_2, CH_4, C_3H_8, and t-C_4H_(10) gas permeability coefficients and diffusion coefficients of poly(4-methylpentene-1) (PMP) with various degrees of crystallization were plotted against the degree of crystallization. The plotdemonstrated a linear relationship. The gas permeability coefficient and diffusion coefficient of pure amorphous and purecrystalline PMPs were evaluated by a linear extrapolation to zero and 100% crystallinity, respectively. The relationshipbetween 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 certaintemperature for 1 h. The desorption of solvent during annealing almost does not result in changes of both the conformation ofbackbone chains and the crystal lattice. We could prepare the mesophase containing molecular cavities with the size andshape of the organic solvent molecules. The mesophase could sorb the same solvent after the manner of Langmuir sorption atlow vapor pressure range while this would not be the case for solvents of different size and shape. This suggests a molecularrecognition of organic solvent, and mesophase SPS might be useful for separation membrane and adsorptive material. 相似文献
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The permeability of copoly (1-trimethylsilyl-1-propyne-pentamethyldisilyl-1-propyne) membrane for twelve gases (0_2, N_2, CO_2, H_2, D_2, He, At, CH_4, C_2H_4, C_2H_6, C_3H_6 and C_3H_8) was examined. The basic laws of solution and diffusion of the gases in the membrane were expounded preliminarily. It was found that a linear relationship between logarithm of diffusion coefficient (D) and critical molar volume (V_c) of the gases. The permeation characteristics of the gases in the copoly (1-trimethylsilyl-1-propyne-pentamethyldisilyl-1-propyne) membrane was also discussed. 相似文献
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双轴取向PET薄膜结晶、织构与超结构的研究 总被引:1,自引:0,他引:1
二类市售12μPET薄膜,即平衡膜与强力膜,应用作者提出的FRS-XRSA与传统的PF以及SAXS进行了比较全面的结构研究。从而获得了有关这些薄膜的结晶、织构与超结构的重要信息与参数,例如:结晶度、晶粒度、(Akl)晶面取向分布全貌与平均取向因子、长周期、晶区尺度、非晶区尺度及电子密度经向分布函数等。这些结构的信息既记录了加工的工艺过程,又对薄膜的各种重要物性,如力学、光学、热学、化学和表面等性质起着决定性的作用。这二类薄膜均可归属于(MT,100)共面、c-晶轴M、T双轴取向的平衡膜或非平衡膜。最后应指出,X-射线法是研究择优取向聚合物结晶、织构与超结构的极为重要的手段。 相似文献