Preparation And Properties Of Hydrophilic Polysulfone Ultrafiltration Membrane

In order to improve the hydrophilicity of polysulfone(PSF)materials,this paper firstly modified the polysulfone chloromethylation and explored the effect of reaction conditions on the degree of polysulfone chloromethylation.The results show that when the concentration of the reactant is 37.5 mg/mL and the catalyst dosage is 0.06 mL,the degree of chloromethylation of polysulfone is the highest and the degree of chloromethylation at this time is 1.25.Chloromethylated polysulfone(CMPSF)ultrafiltration membranes prepared by phase inversion method were investigated by scanning electron microscopy,ultrafiltration performance testing and other characterization methods to investigate the effect of CMPSF concentration on the ultrafiltration membrane structure and performance.Studies have shown that the overall performance of the ultrafiltration membrane is the best when the CMPSF concentration is 17 wt.%,With a flux of 205 L/m~2·h and a rejection rate of 93.08%.We have further modified the polysulfone membrane on the basis of the previous.We grafted p-phenylenediamine onto a chloromethylated polysulfone ultrafiltration membrane by a nucleophilic substitution reaction of chloromethyl and amino.Polysulfone ultrafiltration membrane and chloromethylated polysulfone ultrafiltration membrane were prepared by L-S phase inversion method.The p-phenylenediamine hydrophilic polysulfone ultrafiltration membrane was prepared by grafting p-phenylenediamine with a chloromethylated polysulfone membrane.It was fully characterized by scanning electron microscopy,ultrafiltration new energy test,water contact angle test,and mechanical property test.The results show that the mechanical properties and hydrophilicity of the modified membrane are significantly improved,and the antifouling ability of the modified membrane is also improved by improving the hydrophilicity of the membrane.In addition,the flux of the modified membrane was significantly improved and the rejection rate of the membrane was also improved.The flux reached 285 L/m~2·h and the rejection rate was95.6%.A new kind of hydrophilic polysulphone(CMPSF-TA)was synthesized by grafting taurine onto the chloromethylated polysulfone(CMPSF)via the nucleophilic substitution reaction between chloromethyl and amino group,and the CMPSF-TA materials with different grafting rate of taurine were prepared by controlling the concentration of CMPSF.A series of hydrophilic ultrafiltration membranes were prepared based on the L-S phase inversion method and fully characterized.The results showed that the introduction of the sulfonic acid group changed the morphologies and improved the hydrophilicity of the ultrafiltration membrane,causing the pure water permeability to increase from 152 L/m~2·h to 449 L/m~2·h with a slight loss of retention property of the membrane when the grafting rate of taurine was in the range of 0~0.64.The anti-pollution ability of the modified membranes was also enhanced by for improving the hydrophilicity of membrane,furthermore the flux recovery ratio of CMPSF-TA membranes increased with the increasing of taurine grafting rate,compared with PSF membrane.According to these results,the conclusion can be drawn that grafting taurine on polysulfone is a expected method to improve the performances and prolong the service life of membranes.