Synthesis Of Crosslinked Fluorine-containing Diblock Copolymers By Atrp And Its Applications On The Hydrophobic Films

To our best knowledge, the fluorine-containing block copolymer is merely formed with single methyl meacrylate monomer and a fluorine-containing monomer by ATRP, which leads to poor adhesion and comprehensive property. For improved comprehensive property, the block copolymer was synthesized using fluorine-containing monomer and macroinitiator via ATRP . The micelle was formed when the block copolymer was dissolved in selected solvents, and the coarse structure on the film surface could be constructed with the micells during the process of the formation of film. This approach proves to be ideal for hydrophobic surface.In this contribution, the simulation software, Materials Studio 4.4 (MS), was applied to molecular simulation. Firstly the mesoscopic simulation of the micelle in the solvent was carried out by DPD module. The effect of solvent, chain length and concentration of polymer on the formation and particle size of the micelle was researched. The results show that the core-shell micelle is easily formed in the THF and F113, and the spherical micelle will be assembled with the increase in polymer concentration. Secondly, the surface migration of fluorine-containing functional groups can be concluded from molecular dynamics simulation(MD), migration of fluorine is more easily in block copolymer than in random copolymer, and the fluorine content on the surface is maximum when the film-forming temperature is 353K(80℃),. The simulation results would be used to guide the following experiments.To improve adhesion, macroinitiator P(MMA-HEMA-BMA)-Br was prepared by copolymerization of the functional monomer hydroxyethyl methacrylate (HEMA), methyl methacrylateMMA and butylmethacrylateBMA via ATRP. Ethyl bromide (EPN-Br) was initiator, CuCl was catalyst, 2,2'- bipyridine(bpy) was the complexing agent. The structure of the block copolymers was characterized by GPC, FTIR, 1HNMR. The effects of types of monomers, reaction temperature, catalysts, solvent content on the monomer conversion, molecular weight and molecular weight distribution, the coating properties were investigated. The optimal reaction parameters is that the mole ratio of MMA/HEMA/BMA is 4.5:4.5:1, reaction temperature is 110℃, reaction time is 8h, catalyst system are (EPN-Br/CuCl/bpy), solvent content is 20%. The highest monomer conversion of the product is 73.4%, the molecular weight of block polymer is up to 20000, the molecular weight distribution is 1.49, the adhesion of resin coating is grade 1, hardnessis H.With the acrylic macroinitiator P(MMA-HEMA-BMA)-Br and fluorinated acrylic monomers, fluorinated block copolymer P(MMA-HEMA-BMA)-b-PFMA was synthesized by ATRP. The structure of block copolymer was examined with GPC, FTIR, 1HNMR. The effects of reaction temperature, reaction time, ratio of the monomer and initiator, reaction sequence on the monomer conversion, molecular weight and molecular weight distribution were investigated. The results show that the block polymer with longer fluorinated chains is longer and narrower molecular weight distribution is prepared when the reaction temperature is 130℃, reaction time is 24h, [FMA]:[P(MMA-HEMA-BMA)-Br] = 50:1, the reaction sequence is the synthesis of acrylate macroinitiator firstly, and then is the copolymerization of FMA and macroinitiator.Core-shell micelle can be formed using block copolymer in the selective solvents, such as THF, DMF, F113, 1,1,2,2-Tetrafluoroethyl-2,2,3,3-tetrafluoropropylether. During the process of film formation, micro-nano-structure rough surface can be constructed by the nano-micelle gathering, and fluorine-containing functional groups can immigrate to the surface of the film. The effect of solvent on the water contact angle of film was investigated, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether is in favour of high water contact angle of film. The water contact angle is also increased with the increase in fluorinated chains. When film-forming temperature is 353K(80℃), the contact angle is raised to maximum (135.2°), the coating adhesion is grade 1, hardness is HB.