Synthesis and characterization of poly(vinylidene fluoride-co- chlorotrifluoroethylene)-grafted-poly(acrylonitrile) via single electron transfer-living radical polymerization process

Preparation of functional fluoromaterials through chemical modification of traditional fluoropolymers has been recognized as an economic and convenient strategy to expand the application areas of fluoropolymers. Poly(vinylidene fluoride-co-chlorotrifluoroethylene)-grafted-polyacrylonitrile (P(VDF-co-CTFE)-g-PAN) has been successfully synthesized via single electron transfer-living radical polymerization (SET-LRP) process initiated with macroinitiator P(VDF-co-CTFE) in the presence of trace amount of Cu(0)/tris(2(dimethylamino)ethyl)amine (Me ₆-TREN) in dimethyl sulfoxide (DMSO) at ambient temperature. The typical side reactions happened on P(VDF-co-CTFE) induced by the nitrogen-containing solvents and high reaction temperature in atom transfer radical polymerization process could be avoided in SET-LRP process by using the mild reaction conditions. Well-controlled polymerization features were observed under varied reaction conditions including the different reaction temperature, catalyst concentration, as well as monomer amount in feed. An induction period of 0.5-1.0 h in the polymerization procedure was observed at low temperature, which may be attributed to the Cu ₂O from the surface of the Cu(0) powder. When Cu(0) catalyst is activated, the introduction period is eliminated. The polymerization rates were decelerated by adding excessive Me ₆-TREN for the formation of more stable CuCl ₂/(Me ₆-TREN) ₂. The structure of P(VDF-co-CTFE)-g-PAN was demonstrated by FTIR, NMR, DSC, and TGA.