The Kinetic Studies Of Three Monomers Copolymerization And Synthesis Of Crosslinked Diblock Copolymers By ATRP And Their Applications On The Hydrophobic Film

The coatings prepared by the fluorine-containing acrylic resin are widely used due to theexcellent hydrophobic performance and good film properties. However, the structure andmolecular weight of the resin could not be precisely controlled by the conventional method,and the molecular weight distribution of the copolymers is wide. As a result, the performancesof the resin are relatively poor. Atom transfer radical polymerization (ATRP) is an excellentapproach to avoid the defects of the conventional method, by which the polymers couldobtain better performances. At present, the fluorine-containing block copolymers by ATRPmostly prepare by only single acrylic monomer and fluorine-containing monomer, the filmproperties are poor. Therefore, the aim of this subject is to improve film properties bypreparing fluorine-containing block copolymers with crosslinkable group. Also, the film couldpossess good hydrophobic performance with the fluorine-containing group arranging orderlyon surface and the coarse structure being constructed on the surface. In order to achieve thisgoal, our studies focus on the following aspects:Firstly, the methyl methacrylate(MMA), butyl acrylate(BA) and2-Hydroxyethylmethacrylate(HEMA) were used as the comonomers to preparing the crosslinkablemacroinitiator P(MMA-HEMA-BA)-Br which prepared by ATRP using the CuCl/PMDETAas the catalyst system. The structure of the macroinitiator was characterized by FTIR,1HNMRand GPC, respectively. The effects of temperature, the different kind of initiators, solvent, theratio of catalyst/ligand, the ratio of monomer/initiator, and the addition of deactivator on thepolymerization were investigated. The results show that the polymerization is in bestcontrolled with the optimal reaction parameters as the following: ethyl2-bromopropionate asthe initiator, cyclohexanone as solvent, catalyst/ligand=1:1.5,[M]0:[I]0=200:1, the reactiontemperature as70℃.Secondly, the fluorine-containing block copolymer P (MMA-HEMA-BA)-b-FMA wasprepared by ATRP using the P(MMA-HEMA-BA)-Br as the initiator and CuCl/PMDETA asthe catalyst system. The structure of the block copolymer was characterized by FTIR,1HNMR and GPC, respectively. The effects of the different polymerization route, the reactiontemperature, the amount of macroinitiator and fluorine-containing monomer on the control ofthe polymerization were studied, respectively. The results show that withP(MMA-HEMA-BA)-Br as the initiator, the polymerization could be well controlled. Thecopolymers with narrow molecular weight distribution could be obtained at the reactiontemperature of70℃Finally, the micelle could be formed by dissolving the fluorine-containing blockcopolymers in some solvents. The morphology and size of the micelle were studied by TEMand Malvern Zetasizer Nano S90. The hydrophobic film could be prepared by the micellesolution. The effect of the different solvents, film formation temperature and the micellarsolution preparing methods on the hydrophobic performance of the films were studied, andthe surface topography of the film was observed by SEM. The results show that the blockcopolymer could form core-shell micelle using acetone, C7H4OF12and F113as the solvent;and the micelle size is largest using F113as the solvents. The surface roughness could befacile to construct at low film formation temperature. The superhydrophobic film could beprepared as follows: Initially, the block copolymers were dissolved by a small amount ofacetone, then, add curing agent, finally, the F113was added as the solvent. When the additionof acetone is3.3%of the total weight of solvents, using F113as the solvent, the solutionconcentration is5%, the film formation temperature is80℃，and the curing time is1h, thefilm possesses the water contact angle148, the coating adhesion of grade two, and hardnessof H.