The Research Of Novel Fluorinated Block Copolymers Synthesized Via Iodine Transfer Polymerization

It is difficult to control the chain length and the molecular weight of the fluorine-containing amphiphilic block copolymers when using living polymerization method, because of the mechanism and the infection factor of property of resistance to water and oil on the fluorine-containing segment to bring great difficulties.The advent of controlled radical polymerization(CRP) has provided a novel approach to prepare polymers with controlled molecular weights and with well-defined architecture under easy and mild reaction conditions compared to living ionic polymerizations.The main contents of this article is to synthesize fluorinated amphiphilic block polymer via iodine transfer polymerization. First part, molecular weight controlled PVDF-I have been synthesized by traditional iodine transfer polymerization. In the polymerization, F-113 have been used as the solvent, tert-butyl peroxypivalate(TBPPI) as an initiator, perfluoro iodide hexane(IF-6) as a chain transfer agent, reacting 12 hours at 80 oC in the autoclave, and IR, NMR and other methods were used to characterize the product.The second part, the synthesized of specific molecular weight PVDF-I have been used as first stage macroinitiator, DMF as solvent, AIBN as the initiator to prepare amphiphilic block polymer PVDF-b-HEMA, and some characterizations of the corresponding polymers have been done, such as NMR, IR, contact angle, and then this amphiphilic block copolymers physically mixed with the high molecular weight PVDF resin, DMF and THF was prepared by mixing as the co-solvent, blend films were prepared by way of direct drying. Using a contact angle measuring instrument prepared hydrophilic polyvinylidene fluoride membrane hydrophilic tested through PVDF membrane after the contact angle of a film on the water for five minutes dropped from 101°to 81.2°. By contrast, the untreated membrane decreased from 125.0° to 89.3°, SEM results show that the hydrophilic surface modification of PVDF membrane existence uneven holes, through pure water flux of time after treatment PVDF film is 173 s, without treatment is 389 s. Experimental results show that the experiment was successfully to prepare amphiphilic block copolymer PVDF-b-HEMA, and to prepare a hydrophilic polyvinylidene fluoride blend film.The third part, reversible iodine transfer polymerization was be used, and THF as solvent, AIBN as initiator, elemental iodine as chain transfer agents to synthesize certain molecular weight PTFEMA-I. Then THF have been used as solvent, AIBN as initiator, a specific molecular weight PTFEMA-I as macroinitiator synthetic fluorinated acrylate block copolymer PTFEMA-b-HEMA. And block polymers were tested hydrophilic, block polymers and pure TFEMA contrast, a block polymer membranes for water contact angle two minutes dropped from 93.8 ° to 72.2 °, and the pure TFEMA film from 99.0 ° only dropped to 89.3 °, SEM results show that the distribution of the block copolymer into a uniform block structure. NMR, IR characterization proved to be successful synthesis of amphiphilic block copolymers.