Preparation And Characteristics Of Functional Materials Based On Thiol-Ene Click Chemistry

As a"green"reaction,the thiol-ene click chemistry has many advantages,such as:simple and mild reaction conditions,rapid reaction,insensitive to oxygen or water and so on,which has been widely used in the fields of organic synthesis,material modification and biomedical materials.In this work,the thiol-ene click chemistry was used to prepare two kinds of functional materials,and their properties were investigated.?1?A facile thiol-ene click reaction strategy was employed to form hydrogels in situ.Firstly,the clickable methacrylated hyaluronic acid derivative?HAGMA?was synthesized and characterized,which could take part in the“thiol-ene”click reaction with the prepared thiol-functionalized zwitterionic copolymer?carboxybetaine methacrylate-co-acryloyl cystamine,Poly?CBMA-co-AC??as cross-linker.Then the hydrogels were spontaneously formed under physiological condition and analyzed by scanning electron microscope?SEM?,gel fraction and swelling ratio.Rheology tests indicated that the hydrogels with adjustable stiffness could be obtained by changing the precursor compositions,which would offer more choice to mimic some native tissues for cell culture.The hydrogel consisting of zwitterionic component showed obvious protein resistance and low cell adhesion behavior.Moreover,this zwitterionic hyaluronic acid hydrogel exhibited self-healing property and the degradation test in vitro demonstrated that the hydrogels exhibited good degradation behavior.Besides,the cytotoxicity of the hydrogels was evaluated and the results showed that hydrogels were nontoxic and suitable for further in vivo applications.Human mesenchymal stem cells?hMSCs?were easily encapsulated into the hydrogels and metabolically active,indicating the biocompatibility of the hydrogels.The inflammatory test of hydrogels were carried out and the results suggested that the hydrogels triggered less inflammation and have good biocompatibility.Based on the above results,this clickable hydrogel with excellent performance could be an amenable platform for cells loading application such as soft tissue regeneration.?2?To meet the urgent requirement for the green fluorinated surfactants in practical applications,the preparation of environmentally friendly and nontoxic alternative novel fluorinated surfactants has aroused wide attention in recent years.One of the effective methods to synthesize a novel green fluorinated surfactant is to introduce heteroatoms into the fluorocarbon chain.In this part,a novel fluorinated surfactant was rationally prepared via thiol-ene click chemistry.Firstly,a novel fluorinated surfactant?THESA?was simple synthesized via thiol-ene click reaction between the carbon-to-carbon double bond of heptafluoropropyl trifluorovinyl ether?PPVE?and thiol group of 2-mercaptoacetic acid?TGA?.The structure of the surfactant was analyzed by ¹H NMR,¹⁹F NMR,and FT-IR in detail,the results indicated that the fluorinated surfactant was successfully synthesized.Then the optimal reaction conditions were selected with PPVE:TGA=1:1.2,reaction temperature at 100°C and the reaction time for 18 h.The surface properties of the fluorinated surfactants were measured by the ring method,and the results demonstrated that the novel fluorinated surfactant exhibited lower surface tension(?_cmc,15.86 mN·m^-1)and critical micelle concentration(CMC,21.90mmol·L^-1),compared with the conventional fluorocarbon surfactant?APFO?.Besides,this novel fluorinated surfactant exhibited favorable thermal stability by thermogravimetric analysis,whose initial decomposition temperature is 231.4°C.Compared with APFO,the foaming power of THESA was relatively weak and the foam stability was similar to it.The solubilization ability and emulsifying property of the newly synthesized surfactant were discussed.It was found that the surfactant had good emulsifying property,and the solubilizing power for toluene was 240 mL·mol^-1.All of the results presented in this part indicated that the novel fluorinated surfactant synthesized by the thiol-ene click chemistry exhibits excellent properties and has a wild range of applications.