Fabrication of Solvent-Resistant Copolyimide Membranes for Pervaporation Recovery of Amide Solvents

摘要

Dimethylformamide and dimethylacetamide are important industrial chemicals, which are used, e.g., as solvents in the manufacturing of polyurethane products. They are conventionally recovered by distillation associated with high energy consumption and operating costs. In contrast, pervaporation is an energy-efficient membrane separation method. Ceramic-supported copolyimide membranes were synthesized via the two-step thermal imidization method and applied to pervaporation recovery of dimethylformamide and dimethylacetamide. The prepared membrane demonstrated high resistance to the two amides in a wide concentration range. Effects of operating parameters such as feed temperature and feed concentration on pervaporation performances were investigated. The results showed that the copolyimide membrane is a promising candidate for the recovery of high concentrations of amide solvents.