The Study Of Sulfobetaine Methaceylate For Hydrophilic Modification Of Polysulfone Membrane And Preparation Of Copolymer Hydrogel

The bottleneck for application of polymers is their poor resistance to contamination.In recent years,zwitterionic compounds such as SBMA(sulfobetaine methacrylate)have been widely investigated due to their excellent antifouling properties and have been used for anti-fouling modification of polymer membranes and hydrogels.However,since the zwitterionic compounds are insoluble in most of organic solvents,they can only be used via surface modification.The SBMA hydrogels,though resist adsorption of protein and bacteria,do not allow the attachment of the animal cells as well.Besides,SBMA hydrogels showed poor mechanical properties.In this regard,this thesis aims to overcome the shortcoming of SBMA in application of polysulfone(PSU)membrane modification and hydrogels.Firstly,three block copolymers po lystyrene-b-sulfobetaine methacrylate(PS-b-SBMA)were prepared by continuous two-step Atom Transfer Radical Polymerization(ATRP)method with SBMA content of 11%?28.4%and 39.8%,respectively.The PS-b-SBMA modified PSU ultrafiltration membranes were prepared by blending two products with high SBMAcontent and PSU.As compared to the PSU membrane,the water contact angle of modified membranes decreased with the increase of SBMA content.The modified membranes significantly increased the water flux recovery ratio after treated with 1g/L and l0g/L BSA solution.Moreover,the modified membranes showed less BSA pollution on the membrane surfaces.Secondly,in order to improve the mechanical properties of SBMA hydrogels,DA-P123 obtained by the reaction of acryloyl chloride and Pluronic P123 was mixed with SBMA to prepare copolymer hydrogels.The increase of SBMA content in P(SBMA-co-DA-P123)copolymer hydrogel can increase the swelling ratio of hydrogel.The failure stress of copolymer hydrogels was higher than 0.3MPa,and the fracture strain were about 80%.Moreover,the increase of DA-P123 content increased the failure stress of copolymer hydrogels,the copolymer hydrogels showed better mechanical property than SBMA hydrogel.In addition,the addition of DA-P123 only slightly increased the BS A adsorption on the copolymer hydrogels,and the copolymer hydrogel surfaces had good resistance to Pseudomonas aeruginosa.And copolymer hydrogels neither adhere to vascular endothelial cells nor support cell growth.Finally,to improve the cell compatibility of SBMA hydrogel,methacryloylated gelatin(Gel-MA)prepared by the reaction of gelatin with methacrylic anhydride(MA),was mixed with SBMA to prepare P(SBMA-co-Gel-MA)copolymer hydrogels.It was found that the increase of SBMA could increase the swelling ratio of the copolymer hydrogels when the total monomer concentration(Gel-MA+SBMA)was fixed at 10%.When the Gel-MA content was fixed at 10%,the increase of SBMA content decreased the swelling ratio of copolymer hydrogels.The failure stress of the hydrogel at SBMA:Gel-MA=1:2 was twice high as that of the Gel-MA hydrogel.Antimicrobial adhesion experiments showed that the adhesion of Pseudomonas aeruginosa on the copolymer hydrogels were lower than that of Gel-MA hydrogel,and the e ffect of antimicrobial adhesion increased with the increase of SBMA content.Animal cells adherent experiments showed that when the ratio of SBMA to Gel-MA was range from 1:5 to 1:1,the vascular endothelial cells could grow on the surface of the copolymer hydrogels and eventually cover the whole surface.When the ratio of SBMA to Gel-MA was 2:1,although the vascular endothelial cells can adhere and grow,it can not cover the hydrogel surface.The results showed that Gel-MA significantly increases the cell adhesion of SBMA hydrogel,b ut still retains its ability to resist bacteria and protein contamination.This study on the SBMA modification of PSU ultrafiltration membrane is helpful to improve the effect of polymer membrane in serious pollution such as water treatment.The P(SBMA-co-Gel-MA)copolymer hydrogels can be potentially used as blood contact tissue engineering material,while P(SBMA-co-Gel-MA)copolymer hydrogels is expected to be a new tissue organ repair material.In this regard,this study may promote the application of zwitterionic compounds in tissue engineering.