Preparation And Application Of Novel Water And Oil-Repellent Finishing Agent Containing A Short Perfluoroalkyl Chain

In order to satisfy the requirements of the working in a special environment, the development of water-repellent and oil-repellent finishing agent for textiles is growing rapidly and widely. Because of their excellent performance of water-repellent, oil-repellent and antifouling, the fluorinated finishing agents are widely applied in the field of the functional finishing. Organic perfluorinated compounds with a long perfluoroalkyl chain (-CnF2n+i, n≥8), especially as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), have an extremely low surface free energy and good performance, such as excellent efficiency to repel water, oil and stain, good air permeability and so on. So they have already been widely used in the field of fabric dyeing and finishing. However, due to its high bioaccumulation, difficult biodegradation and long-distance migration, it was harmful to human beings and had been caused widespread concern all over the world. Its application has already been limited by the European Union, so development of the novel and environment-friendly fabric finishing agent containing a short perfluoroalkyl chain(-CnF2n+i, n<8) to substitute PFOS is extremely urgent.In this paper, the new surfactant N-propyl-N-hydroxyethyl perfluorohexyl sulfonamide by self-made was used as a raw material, and the novel acrylate monomers containing a short perfluoroalkyl chain2-(N-propyl perfluorohexyl sulfonamido) ethyl acrylate (C6F13SO2N(C3H7)CH2CH2OCOCH=CH2) was synthesized through alcoholysis reaction. Afterwards the monomer of fluorinated acrylic ester was polymerized with octadecyl acrylate and2-ethoxyl acrylate by the emulsion polymerization and finally the finishing agent was applied to the cotton fabric.This paper is divided into three parts:(1) N-propyl-N-hydroxyethyl perfluorohexyl sulfonamide by self-made was used as a raw material, and the novel acrylate monomer containing short perfluoroalkyl chain2-(N-propyl perfluorohexyl sulfonamido) ethyl acrylate (C6F13SO2N(C3H7)CH2CH2OCOCH=CH2) was synthesized through alcoholysis reaction. The structure of acrylate monomer was characterized by FT-IR,1H-NMR,13C-NMR. The optimum reaction conditions were studied by solvents, temprerature, time, molar ratio of reactants through the influence for the yields. The optimum reaction conditions were:the solvent was chloroform; the reaction temperature was45℃, and the reaction time was7h; N-propyl-N-hydroxyethyl perfluorohexyl sulfonamide:acryloyl chloride:n-propylamine (molar ratio) was1:2.5:2.5.(2) The monomer of fluorinated acrylic ester was polymerized with octadecyl acrylate and2-ethoxyl acrylate by the emulsion polymerization and the obtained finishing agent was characterized by FT-IR. The optimum polymerization conditions were:the concentration of initiator (ammonium persulfate) was0.8%; the concentration of mixed emulsifiers (OP:SDS=2:1(w/w)) was4%; the reaction temperature was75℃; and the reaction time was4h.(3) The cotton fabric was treated by the obtained finishing agent. After discussing the effect of the monomer content in finishing agent, the concentration of finishing agent in finishing solution, curing temperature and time on the efficiency to repel water and oil, the optimum finishing process was obtained. That was:the molar percent of fluorinated acrylate monomer in the finishing agent was60%; the concentration of finishing agent in finishing solution was6%(w/w), curing temperature was160℃; curing time was120s. Cotton fabric treated with above process had excellent water and oil-repellent properties with water contact angle up to 138.5°, and126.8°as the liquid paraffin contact angle, and n-tetradecane contact angle up to105.8°, as well as good durability.