Synthesis Of Fluoropoly Acrylate-polyether Block Copolymer Via Atom Transfer Radical Polymerization And Its Property

In this dissertation, a series of ABA fluoropolyacrylate-polyether block copolymer with different molecular weight were synthesized via atom transfer radical polymerization(ATRP). Surface tension of copolymer emulsion and solution were tested. Films of copolymer were prepared by spin coating tech. Chemical composition and surface property of the films were tested by X-ray photorlectron spectroscopy(XPS) and the surface contact angle, and surface morphology was observed by atomic force microscopy(AFM). The copolymer emulsions were applied on fabric finishing and the relationship between structure and property was studied systematically.The macroinitiator was prepared by esterification using polyethylene glycol and2-Bromoisobutyryl bromide as raw materials and triethylamine as the acid-trapping agent.ABA fluoropolyacrylate-polyether triblock copolymers were synthesized via ATRP using fluorinated acrylate as monomer and well-defined Br-PEG-Br as macroinitiator. The structure of copopymers was characterized by infrared spectroscopy(IR), nuclear magnetic resonance spectroscopy(NMR) and gel permeation chromatography(GPC), and the results confirmed that the polymerization procedure had a strong controllability. The research showed that, in the absence of an emulsifier, the fluoropolyacrylate-polyether block copolymers can self-emulsified to obtain the emulsion with particle size less than 300 nm,and the surface tension of the resulted emulsion was reduced to 23.9mN/m. Dissolving the copolymer into ethyl acetate can significantly reduce the surface tension of the resulted solution to as low as 19.6mN/m.Surface properties of block copolymer films were studied. It was found that the fluorine content on the film surface had a very difference before and after heat treatment,and contact angle(CA) test results showed that water contact angle of films had a certain degree of increase after heat treatment. We also found that the surface of the polymer film was filled with numerous pinnacles by AFM test. All these results showed that fluoroalkyl groups can migrate towards the outermost surface of the copolymer films under heattreatment due to the microphase separation.A series of fluorinated block copolymers with different fluorine content were prepared via ATRP by using fluorinated acrylate monomer, methyl methacrylate(hard monomer),butyl acrylate(soft monomer), hydroxy ethyl methacrylate(crosslinking monomer) and macroinitiator as raw materials, to form the coploymeric block, under copper catalytic systems. The structure of copopymers was characterized by FT-IR, NMR and GPC.Surface properties of the copolymer films were tested by XPS, AFM and CA. It was indicated that water and n-hexadecane contact angle increase gradually with incrent of fluorine content. Surface free energy of four polymer films was calculated to be as low as0.96×10-2N/m. The copolymeric block polymer was applied on fabric finishing and the result showed that good water repellency can be obtained with additional thermal property improvement. When fluorine content was fixed on 28%, water proofing score of treated fabric reached 100′and contact angle is up to 135°. But unfortunately, it was found that water resistance sharply decreased after 10 cycles of washing, which showed that waterproof durability should be further improved.