Preparation of phase-transfer catalytic porous membrane by γ-ray irradiation grafting and its application in nucleophilic substitution reaction

• Phase transfer catalytic porous membranes are used in liquid–liquid reaction.
• Catalytic membrane was prepared by γ-ray irradiation grafting and quaternization.
• Catalytic membrane exhibits good activity in nucleophilic substitution reaction.

Phase-transfer catalytic porous polyethylene membranes, prepared by γ-ray irradiation grafting of 4-vinyl pyridine and quaternization, were tested in nucleophilic substitution reaction. The effects of grafting conditions (irradiation dose, 4-vinyl pyridine concentration) and quaternization parameters (temperature, time, concentration of reagent) were investigated. It was found that, the grafting degree initially increases with irradiation dose or 4-vinyl pyridine concentration and then decreases. The ion exchange capacity and quaternization ratio of membranes rise with quaternization temperature, time, and reagent concentration. The quaternized membranes exhibit good phase-transfer activity in nucleophilic substitution reaction between n-bromooctane and KI aqueous solution. The n-bromooctane conversion and the observed reaction rate constant rise with the increase in ion exchange capacity of membranes or reaction temperature. This paper provides a novel and promising method for phase transfer catalysis.

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