(442e) Pure and Mixed-Gas Permeation Study Of Thermally Rearranged Polymers
Results of pure and mixed-gas permeation in thermally rearranged polymers are presented. Polyimide precursor films were converted to their polybenzoxazole (PBO) analogs to varying degrees using different thermal treatment protocols. Structure/property relations in this family of polymers are described. Mixed-gas permeation results are compared against pure-gas measurements. Interestingly, CO2/CH4 mixed-gas selectivity at 35°C was 20-30% higher than the simple ratio of pure-gas permeabilities. Strong dual-mode effects were responsible for a decrease in CH4 permeability in the presence of CO2, with very little change to CO2 permeability in the mixture. Plasticization is not evident in the pure-gas CO2 permeation data.