Role of fluorocarbon surfactant in the preparation of polytetrafluoroethylene-modified polyacrylate emulsion

Role of fluorocarbon surfactant in the preparation of polytetrafluoroethylene-modified polyacrylate emulsion is investigated. The fluorocarbon surfactant has an efficient preemulsification to polytetrafluoroethylene (PTFE) powder. It enables PTFE powder to be introduced into the copolymer of n-butyl acrylate, n-methyl methacrylate, n-styrene, and a-methacrylic acid. Thereby, stable PTFE-modified polyacrylate emulsion can be formed. The effects of fluorocarbon surfactant on the surface tension, particle size and particle size distribution of the emulsion, as well as the relation between fluorocarbon surfactant and the amount of PTFE powder are fully investigated. The particle size and the surface tension of emulsion strongly depend on the fluorocarbon surfactant concentration in the reaction system. The particle size distribution becomes narrower and the stability of the emulsion is improved with the increasing of the fluorocarbon surfactant concentration. According to the experiments, a possible mechanism of fluorocarbon surfactant in polymerization is proposed. (c) 2007 Wiley Periodicals, Inc.