Study On Synthesis Of Fluorine-containing Acrylate Block Copolymer By Atom Transfer Radical Polymerization

Fluorine-containing acrylate polymer had a good surface properties, stability, oxidation resistance, corrosion resistance, because of the modified role of fluorine atom, as well as good hydrophobic, oleophobic and stain resistance. In this article the block copolymer of methyl methacrylate (MMA) and thirteen fluorine octanol methyl methacrylate (FAEM) were synthesized by Atom Transfer Radical Polymerization (ATRP) in the solution system.The polymerization included two parts.In the first step poly methyl methacrylate with bromine in the end of the chain were synthesized.In the second step,the block copolymer of methyl methacrylate and thirteen fluorine octanol methyl methacrylate (P(MMA-b-FAEM)) were synthesized with PMMA-Br as the macroinitiator. In this article, massive experiments has been carried on by changing the synthetic conditions,such as the reaction temperature, the reaction time, the initiator, the catalytic system and so on.The block copolymer were initiated by microinitiator with different designed molecular weight. In these experiments, the impact of various factors were discussed by measuring the monomer conversion, molecular weights and molecular weight distribution, as well as the research of kinetics of the polymerization reaction. Then the optimum reation conditions were drawed. The structure and compositions of the block copolymer have been characterized by infra-red (IR), nuclear magnetic resonance spectroscopy (both 1H-NMR and 13C-NMR) and their molecular weights and polydispersitivity index (PDI) were measured by gel permeation chromatography (GPC). After the goal polymer was proved, surface hydrophobic properties of fluorine-containing block copolymers were studied by measuring the contact angle.Experimental results show that suitable formula and conditions of synthesizing of fluorine-containing acrylate block copolymers is that PMMA-Br is the macromolecular intiator, reaction temperature is 90℃, the ligand is bpy, cuprous chloride is catalyst, while macromolecular intiator: bpy: cuprous chloride is 1:1:2, the reaction time is 24 hours. Polymerization synthesis of the target product had a good control of polymer molecular weight and narrow molecular weight distribution (PDI = 1.28). It was achieved that, the surface contact angle of polymer film was achieved 105 degrees, with a small amount of fluorinated monomer (the weight percentage of fluorine in the polymers 3.89%) feeded, which proved the block copolymer had a good water-repellent. In addition, the surface hydrophobic properties of block copolymers mainly depended on the length of fluorinate-containing block, and the length of PMMA had little effect on the surface properties of block copolymer.