Synthesis of fluorinated silicon-containing amphiphilic copolymer and its demulsification performance

Abstract A series of novel fluorinated silicon-containing copolymers were prepared by atom transfer radical polymerization (ATRP). This was achieved by polymerization of 2,2,2-trifluoroethyl methacrylate (TFEMA) with the dimethylchlorosilane terminated allyl-substituted poly(ethylene glycol) (PEG). Their demulsification performance for low-temperature coal tar (LCT) /water emulsion were evaluated via bottle tests. The influences of demulsifier dosage, settling time and temperature on the demulsification efficiency were investigated in detail. The copolymers were able to remove more than 90% LCT from the LCT emulsion and provide good demulsification performance. The interfacial tension and interfacial rheology properties of LCT emulsions in the presence of the copolymers were systematically discussed. The results revealed that the copolymers did not affect the interfacial tension of the emulsion significantly, but decrease the elasticity of the interface film obviously. The solvophobicity of PTFEMA chains can not only effectively improve the diffusion rate of the polymer from the bulk to the interface, but also destroy the interfacial film structure and promote the coalescence of emulsion droplets.