Research ATRP Synthesis PS-b-PAA Amphiphilic Copolymer And Porous Membrane Preparation

Atom transfer radical polymerization (ATRP) is a new kind of radical living polymerization method first reported by Matyjaszewski and Wang Jinshan in1995. In recent years, the atom transfer radical polymerization has become an important research field in polymer material, and was received more and more attention by polymer chemists. Not only controllable molecular weight homopolymer, but also the copolymer of clear structure can be prepared use this polymerization method. With the development of a series new catalytic system, more and more monomers can be prepared by atom transfer radical polymerization.The basic principle of atom transfer radical polymerization is:A dynamic reversible equilibrium is formed between the active species and the dormant species which undergoes the transfer of the halogen atom X between initiator catalyst and the growth polymer chain. Thereby reducing the concentration of the active radical species, and significantly reducing the inherent chain termination reaction. In order to enable the polymerization can be controlled, many reaction conditions need to be optimized, such as the kind of solvent, the amount of solvent, the type of catalyst, the amount of catalyst, the amount of initiator, reaction temperature, reaction time, etc.The monodisperse PS with end group of Br was synthesized by using MBrP as the initiator, CuX/PMDETA as the catalyst system to polymerize styrene according to atom transfer radical polymerization (ATRP) mechanism. The structure of the polymer were characterized by GPC、 FTIR、TG. The reaction condition such as the nature of solvent、the amount of solvent、the reaction temperature、the kinds of catalysts、the ratio of catalyst and initiator was studied and optimized.Four different polymerization reaction system (MBrP:CuBr:PMDETA:St=1:1:2:100/MBrP: CuBr:PMDETA:St=1:1:2:150/MBrP:CuBr:PMDETA:St=1:1:2:200/MBrP:CuBr:PMDETA:St=1:1:2:300)was confirmed as the active polymerization under the optimal reaction conditions. The controllability of atom transfer radical polymerization was mainly relied on the low concentration of free radical in the reaction system, so it is not a truly active polymerization. A certain degree of double-terminated reaction was still exists in the polymerization reaction, resulting a amount of dead dimmer (non-active end groups of the polymer) were exists in the polymerization product. We find the polymerization reaction system (MBrP:CuBr:PMDETA: St=1:1:2:100) deviate the activity characteristics at the later period of the polymerization. We find the end groups of polymerization product at the later period were almost disappeared by ’H-NMR test. The product was found remained basically unchanged under the chain extension. we believe that the polymerization product under that condition can not be used as the macroinitiator.By using PS-Br as the macromolecules initiator, CuBr/PMDETA as the catalyst to polymerize tB(M)A according to atom transfer radical polymerization (ATRP) mechanism, characterized by GPC、FTIR、1H-NMR、TG. The reaction condition such as the amount of solvent、the reaction temperature、the ratio of catalyst and initiator、the ratio of initiator and monomer、the reaction time was studied and optimized.In recent years, the honeycomb-patterned porous film has important applications in many areas such as the separation membrane、micro-reactor、chemical sensors、photonic band gap、 tissue engineering, has been received extensive attention from scientists. We use the different molecular weight polystyrene with polar group-bromine and the amphiphilic block copolymer as the film material to prepare honeycomb porous film use the breath figure method.