The Preparation,Structure And Properties Of Crosslinked Polyacrylonitrile Membrane

To meet the requirements of separation and water treatment in industrial production,the efficient and green membrane separation technology have made great progress in the past few decades.But there are still many defects,especially the damage of membrane structure and membrane fouling in the process.Therefore,the membrane with strong mechanical strength and anti-pollution performance are designed to reduce the replacement and improve the use efficiency.This paper was described a facile method for the synthesis of polyacrylonitrile random copolymer containing allyl functional side groups.Then,crosslinked membranes were prepared by UV induced thiol-ene reaction.The random copolymer of acrylonitrile and methacrylicacid allyl ester was synthesized by free radical polymerization under the condition of azo-bis-isobutyronitrile(AIBN)as initiator,and cysteamine hydrochloride as chain transfer agent.The copolymers were characterized by FT-IR,NMR,and GPC.Results indicated that the structures of the products containing allyl side groups.The effects of initiator concentration,crosslinking time and ultraviolet intensity were also investigated when the crosslinked membranes were prepared by UV irradiation under the condition of thiol as crosslinker.Results showed that the optimum conditions of the membranes curing were as follow: initiator concentration was 5wt.%,crosslinking time was 60 s and UV lamp power was 800 W(working distance as 50 cm).The different crosslinking degree membranes were prepared by changing the content of crosslinking agent.The membranes were characterized by tensile tests and water flux test which indicated that the mechanical properties of the membranes increased,the membrane water flux decreased with the increase of the crosslinking degree.SEM images showed that the outer surface structure was changed little.But the cross section was gradually changed to the uniform dense layer transition with the increase of the crosslinking degree.The copolymer of acrylonitrile,zwitterionic compound(SBMA)and allyl methacrylate was prepared by the same way.The mechanical properties and solvent resistance of the membranes were characterized by tensile test,fracture strength test and swelling test.Bovine serum albumin was used to study the anti-protein adsorption ability of the membranes,and the filtration experiments of pure water and bovine serum albumin solution were also carried out.The results showed that the crosslinked membranes had excellent mechanical strength,solvent resistance and protein resistance.