| Summary: | 碩士 === 元智大學 === 化學工程研究所 === 89 === The physical aging in the poly[1-(tri- methylsilyl)-1-propyne] (PTMSP) membranes prepared with various casting solvents were studied. It has been observed that the specific volume of the membranes and the permeabilities of gases through the membranes decayed with time. The bulk and pycnometric density of the membranes increased with time due to the microstructure change of the polymer membranes. However, the increasing rate of the membrane pycnometric density was higher than that of the membrane bulk density, resulting from an inner rearrangement of distribution of free volume and a greater reduction rate of the interstitial free volume. PTMSP membranes prepared by different casting solvents showed different changing rates of permeability and specific volume, but the decay rate constant of the permeability (kp) is proportional to the decay rate constant of the specific pycnometric volume (kv). It is shown that the changing rates of the membrane density and permeability increased with thermal treating temperature. The aging results obtained at the elevated temperatures were consistent with those at room temperature. After treating the aged membranes with a solvent vapor, decayed membrane permeabilities could be partially recovered.
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