Oxygen permeability coefficients

Table 9 Oxygen permeability coefficients (P02) and P02/PN2 of gas permeable substituted polyacetylenes...

Figure 2.24 Correlation of the oxygen permeability coefficient for a family of related polysulfones with inverse fractional free volume (calculated using the Bondi method) [33]. Reprinted with permission from C.L. Aitken, W.J. Koros and D.R. Paul, Effect of Structural Symmetry on Gas Transport Properties of Polysulfones, Macromolecules 25, 3424. Copyright 1992, American Chemical Society...

Figure4.3 Oxygen permeability coefficients of poly (2,6-dimethyl-1,4-phenylene oxide) (PPO) films of various thicknesses, as a function of aging time at 35 °C [52], Reproduced with permission of the American Chemical Society.

Hydrogen and Oxygen Permeability Coefficients Literature Values... 

Fig. 6. Oxygen permeability coefficient (Po2) and selectivity (Po2/Pn2) of typical polymers and substituted polyacetylenes (membrane thickness 30 pm, 25 °C)...

A plot of the logarithim of the oxygen permeability coefficients versus the reciprocal of the SFVs, as proposed by Lee, shows a fair correlation between these values. Data for the polyetherimides and polyarylates (Figure 3) is meager, but does allow some general conclusions to be drawn. The model does apparently overestimate the permeability for the bisphenol A based PEI 24. In addition, the fit of the polyarylate data with the calculated model is favorable except for an overestimation of the permeability of the bis(4-hydroxy-... 

Figure 2 shows the oxygen permeability coefficient for EvOH-32 as a function of water content at 20C. The oxygen barrier effectiveness of EvOH-32 decreases markedly with the absorption of water because of plasticization of the EvOH-32 matrix. 

The addition of plasticizer used for the improvement of mechanical properties leads generally to an increase in the oxygen permeability coefficient due to the higher mobility of the polymer chain and higher free volume [102]. On the contrary, the dispersion of nanoclays in PLA makes it possible to divide the permeability coefficient by 2 or 3 depending upon the type of the nanoclays (e.g. organomodified montmorillonite, cloisite 25A or 30B, organomodified synthetic fluorine mica) and exfoliation [129-131]. 

Calculate the total oxygen permeability coefficient of the following multilayer structure (P given in cc mil/100 in d atm, thickness in mils). 

Properties for several TFE/PDD copolymers and PTMSP are compared in Table IV. Density and glass transition temperatures for the TFE/PDD copolymers were obtained from Buck and Resnick (44), and the density and glass transition temperature for PTMSP are from the study of Nakagawa et al.(l). Among the fluoropolymers in this table, PTFE homopolymer exhibits 5ie lowest glass transition temperature, the lowest oxygen permeability coefficient, and the lowest fractional free volume. In the polymers in Table IV, the PALS results suggests a bimodal distribution of free... 

Oxygen permeability coefficients for each polymer were measured at least 3 times and the deviations were 5-15%. The permeability coefficients listed in Tables 1 and II are the average values. 

Figure 5. Oxygen permeability coefficients of (alkylsulfonyl)methyl-substituted poly(oxyethylene) as a function of the number of carbon in the alkyl side chains.

Figure 8. Oxygen permeability coefficients ( ) and densities (O) of MSEE/MST blends.

Figure 13.15. Oxygen permeability coefficient of ethyl cellulose vs. weight fraction of tributyl citrate. [Data from Beck M 1 Tomka 1, J. Polym. Sci. Polym. Phys. Ed, 35, No.4, March 1997, p.639-53.]...

Fig. 2 presents the oxygen permeability coefficient for PLA 98% L-lactide (98L-PLA) as a function of water activity. A significant increase of the oxygen permeability coefficient as temperature increases can be observed for 98L-PLA. 98L-PLA shows an increase of the oxygen permeability coefficients from 3.5 X 10 kg m/(m s Pa) at 5°C to 11 X 10 kg m/(m s Pa) at 40°C when moisture is not present. At a higher water activity level (A = 0.9), the value of the oxygen permeability coefficient increases only to 8.5 X 10 kg m/(m2 s Pa) at 40°C. This reduction of the oxygen permeability coefficient as water activity increases at a constant temperature is observed in Fig. 2 for the three temperatures tested. The reduction is more pronounced at 40°C. 

Fig. 2. Oxygen permeability coefficient as a function of water activity for 98L-PLA.

Table 4. Oxygen Permeability Coefficients (PO2) and PO2/PN2 of Highly Permeable Substituted Polyacetylenes...

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