Preparation And Application Performance Of Fluorine Free Water-repellant Finishing Agents

To avoid the using of perfluorooctasulfamide(PFOS), using siloxanyl groups and long-chain alkyl as hydrophobic groups, this dissertation focused on the preparation of novel siloxanyl methaacrylate copolymeric emulsion and cationic long-chain emulsion. These emulsions were applied on fabrics finishing and the relation between water repellency and structure was also studied.Using allyl methacrylate, 1,1,3,3-tetramethyldisiloxan and trimethyl chlorosilane as raw materials, siloxamethacrylate monomer named γ-(1,1,3,3,5,5,5-heptamethyltrisiloxyl)propyl methacrylate was synthesized and characterized by FT-IR, 1H NMR and 29 Si NMR. Subsequently,the homopolymer was prepared with number molecular weight to be 18766,weight molecular weight 30639,and the dispersity of 1.633. The glass transition temperature(Tg) was identified to be 107.8℃.Then siloxamethacrylate monomer was copolymerized with butyl acrylate(BA) and methyl methacrylate(MMA) to obtain siloxamethacrylates copolymer emulsion. The effect of monomer dosage on particle size, zeta potential and thermal stability was discussed. The produced latex was applied on fabric finishing and afforded water repellency. The optimized emulsion polymerization process of the copolymeriation with soft monomer butylacrylate was found to be as following: mole ratio of siloxamethacrylate and BA is 2:1, the reaction temperature is 70℃ and the reaction time 3h, the emulsions were coated onto cotton fabrics providing a contact angle of 128.3 °. The optimized emulsion polymerization process of the copolymeriation with rigid monomer methylmethaacrylate was found to be: mole ratio of siloxamethacrylate and MMA is also 2:1, the emulsions provide the treated cotton fabrics with a contact angle of 129.4°.The results suggested that siloxanyl can be used as water repellent group and the treated fabric can be more thermal stable.We also prepared a kind of cationic emulsions by octadecyl acrylate and methyl methacrylate with the optimized process conditions as follows: the mass ratio of octadecyl acrylate and methyl methacrylate was 4:1, the dosage of emulgator of octadecyl ammonium chloride was 4%, the reaction temperature was 75℃, and the reaction time was 3h. This latex was applied on fabric water finishing to achieve the contact angle of 132.7°and spraying goal of 80 point. The result suggested that long-chain alkyl can provide water repellant performance without fluorine element.