UV irradiation grafting of butyl acrylate on polyimide membrane for enhanced lubricant solvent recovery

As one single membrane material could not fulfill the requests of chemical stability, mechanical strength, and resistance to pollution in practical applications. Modifications of the membrane to improve its separation performance were of great significance. In this study, UV irradiation grafting modification was employed and butyl acrylate was selected as a modification monomer for polyimide membrane to improve its lipophilicity and separation efficiency in lubricant solvent recovery. And effects of monomer concentration, irradiation distance, and grafting time on the grafting results and separation properties of modified polyimide membranes were investigated. The results exhibited that modified polyimide membranes obtained an enhanced lubricant retention rate compared with raw membranes, which increased from 66.5% to 93.1%. The industrial test for 40 days proved the great stability of modified polyimide membranes. Overall, this work confirmed the good industrial utilization potential of modified polyimide membranes and offered an effective way for lubricant solvent recovery.