Synthesis and characterization of fluorinated polyimides for pervaporation of n-heptane/thiophene mixtures

摘要: Abstract Soluble fluoro-polyimides have been synthesized by reacting of a fluorine-containing aromatic dianhydride, 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane with diamine to yield poly(amic acid)s which were then cyclized polyimide chemical imidization method. The polyimides excellent solubility both in strong bipolar solvents, such as NMP and DMAc, common organic THF dioxane, etc. glass transition temperature these determined DSC ranged from 281 289 °C. Thermogravimetric analysis indicated that good thermal stability initial decomposition 520–526 °C. asymmetric membranes prepared phase inversion method the inner structure was observed SEM. pervaporation properties for n -heptane/thiophene mixtures investigated at 40–77 °C permeation flux sulfur enrichment factor are range 0.56–1.68 kg/m 2  h 3.12–2.24, respectively. result demonstrated could be very effective desulfurization ultrathin skin.