Gas transport properties in polycarbonate films with various unrelaxed volumes

Hachisuka, Hisao; Takizawa, H.; Tsujita, Yoshiharu; Takizawa, Akira; Kinoshita, Takatoshi

doi:10.1016/0032-3861(91)90078-w

Cited by 27 publications

(14 citation statements)

References 22 publications

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“…41,42 A membrane, which was held in the permeation cell sealed with O-rings, was degassed for 24 h or more at less than 10 −5 cmHg in the permeation apparatus. Downstream side of the membrane was evacuated and remained about 10 −5 cmHg.…”

Section: Gas Permeation Measurementsmentioning

confidence: 99%

Characterization of the Cavity in Poly(4-methyl-1-pentene) Crystal by Gas Permeation and 129Xe NMR Measurements

Suzuki

Tanaka

Nakajima

et al. 2002

Polym J

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ABSTRACT:Characteristic cavity in a crystal part of poly(4-methyl-1-pentene) (PMP) has been investigated by gas permeation and 129 Xe NMR measurements for PMP membranes with various crystallinities. For the cavity, permeability coefficients of He, N 2 , O 2 , CH 4 , and CO 2 have shown finite values, whereas those of C 3 H 8 and tert-C 4 H 10 have shown zero. From the analysis of 129 Xe NMR chemical shifts of 129 Xe sorbed in PMP membranes, it has been able to evaluate the size of the cavity in PMP crystal as about 4.5 Å. These findings have indicated that gas molecules less than about 4.5 Å can permeate the cavity in PMP crystal.

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Section: Gas Permeation Measurementsmentioning

confidence: 99%

Characterization of the Cavity in Poly(4-methyl-1-pentene) Crystal by Gas Permeation and 129Xe NMR Measurements

Suzuki

Tanaka

Nakajima

et al. 2002

Polym J

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“…The occupied volume was calculated in the present study using SanchezLacombe's equation of state 29,30 based on the V-T curve observed for PPO in the liquid state from published data. 26,27 The calculated temperature dependence of the occupied PPO volume is shown in Figure 2 with its V-T curves. The characteristic temperature, T 2 , was predicted to be À75±20 1C from the intersection between the temperature dependence of the occupied and specific volumes at the hypothetical equilibrium supercooled liquid state, as shown in Figure 2.…”

Section: Resultsmentioning

confidence: 99%

“…This annealing condition was nearly identical to that in the investigations of PPO by dilatometry reported elsewhere. 26,27 The PPO-coated quartz oscillator was subsequently installed inside a home-made quartz crystal microbalance cell with a metallic seal. After drying at approximately 10 À3 mm Hg, Xe was introduced into the cell at various pressures.…”

Section: Methodsmentioning

confidence: 99%

Temperature dependence of the mean size of polyphenyleneoxide microvoids, as studied by Xe sorption and 129Xe NMR chemical shift analyses

Yoshimizu

Ohta

Asano

et al. 2012

Polym J

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Both the Xe sorption isotherms and 129 Xe NMR spectra of poly(2,6-dimethyl-1,4-phenylene oxide), PPO, were obtained across a temperature range of -55 1C to þ 80 1C to investigate the temperature dependence of the gas sorption and the unrelaxed volume of PPO. All of the obtained sorption isotherms were analyzed based on the dual-mode sorption model, and the Langmuir saturation constant, C H 0 , which corresponds to the unrelaxed volume, was determined by curve fitting. The values of C H 0 increased linearly with decreasing temperature, and the obtained temperature was almost identical to the glass transition temperature, T g , of PPO when the C H 0 value was extrapolated to 0. The 129 Xe NMR chemical shift of 129 Xe in the PPO showed a nonlinear, low-field shift with increasing Xe pressure at temperatures below the T g . The mean volumes of individual microvoids were determined at each temperature based on the 129 Xe NMR chemical shift analysis, assuming a fast exchange of the Xe atoms between the Henry and Langmuir sorption sites. The temperature dependence of the individual microvoid volumes was similar to that of C H 0 .

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“…Physical modifications such as thermal quenching and pressure conditioning from the liquid state were tried for glassy polymers (15)(16)(17). Such processes effectively alter the physical rather than the chemical structure of the polymer.…”

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confidence: 99%

Effect of Microwave Irradiation on CO₂ Permeability in Cellulose Acetate Membranes

Tsujita

Nakai

Yoshimizu

et al. 2004

ACS Symposium Series

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Gas transport properties in polycarbonate films with various unrelaxed volumes

Cited by 27 publications

References 22 publications

Characterization of the Cavity in Poly(4-methyl-1-pentene) Crystal by Gas Permeation and 129Xe NMR Measurements

Characterization of the Cavity in Poly(4-methyl-1-pentene) Crystal by Gas Permeation and 129Xe NMR Measurements

Temperature dependence of the mean size of polyphenyleneoxide microvoids, as studied by Xe sorption and 129Xe NMR chemical shift analyses

Effect of Microwave Irradiation on CO₂ Permeability in Cellulose Acetate Membranes

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Gas transport properties in polycarbonate films with various unrelaxed volumes

Cited by 27 publications

References 22 publications

Characterization of the Cavity in Poly(4-methyl-1-pentene) Crystal by Gas Permeation and 129Xe NMR Measurements

Characterization of the Cavity in Poly(4-methyl-1-pentene) Crystal by Gas Permeation and 129Xe NMR Measurements

Temperature dependence of the mean size of polyphenyleneoxide microvoids, as studied by Xe sorption and 129Xe NMR chemical shift analyses

Effect of Microwave Irradiation on CO2 Permeability in Cellulose Acetate Membranes

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Effect of Microwave Irradiation on CO₂ Permeability in Cellulose Acetate Membranes