Fluorinated polyimide nanocomposites for gas separation

摘要

This paper discusses the synthesis and characterization of fluorine-containing poiyimides, both the usual aromatic and less common aliphatic varieties, and nano-composite membranes therefrom in order to study the stabilities and gas permeation rates and selectivities Poiyimides were synthesized, from 2,2-bi$(3,4-anhydrodicarboxy phenyl)hexafluoropropane (6F dianhydride,6FDA) and 4,4'-diaminodiphenyl ether (oxydianiline, ODA) and from several aliphatic diamines into which were incorporated nanoparticulate additives. Polyamic acid films were solvent cast cured at 200°C then post-cured at 300°C and measured for permeation data and for thermal properties. The inclusion of clay commonly causes a decreased permeation rate while the addition of TiO2 improves the rate and selectivity. Treating the nanofillers with surfactant decreases selectivity and marginally increases rate of permeation of CO2.