Synthesis And Application Of Polysiloxane-urethane Water Dispersion As Textile Finishing Agent

Recently, Textile with water-repellency is one kind of the funtional textiles which are under great demand and applied in many fields. Meanwhile, people pay more attention to the research and development of the water-repellent finishing agent.Polysiloxane has many excellent properties, such as low surface energy and heat resistance. Textiles finished with polysiloxane show soft handle and water-repellency properties, but have low adhesive strength and bad water-washing serviceability. Polyurethane has been used as textile finishing agent for high toughness and good adhension, which can endow textile good water-washing serviceability, but water-repellency of the textile isn't good. Polysiloxaneurethane water dispersion (PSUWD) with good water-repellency, water-washing serviceability and environmental protection was synthesized as the water-repellent finishing agent.In this dissertation, PSUWD was synthesized by two ways. Firstly, PSUWD-1 was prepared using maleic anhydride as the carboxyl diol, N-β-(aminoethyl)-γ-aminopropyl-methyldimethoxy silane (602) as the main chain extender. Meanwhile, self-made amino-terminated polydimethylsiloxane (SN₂) was also used as the chain extender, which improved the water-repellency of the copolymer film. Secondly, PSUWD-2 was prepared using dimethylolpropionic acid (DMPA) as the carboxyl diol, SN₂ and self-made amino-terminated polydimethylsiloxane with long branch chain (S₃N₂) as the main chain extenders. Effects of chain extender type, carboxyl content, the ratio of SN₂ to S₃N₂ and siloxane content on the particle size, rheological property, water-repellency, thermal stability and mechanical property were studied. It was found that when the carboxyl content was 1.8 wt%, the system represented good comprehensive properties. As the content of S₃N₂ and the siloxane increased, the particle size became bigger, and the swelling ratio decreased.At last, the optimized formula of PSUWD-2 as the water-repellent finishing agent was dermined. The bonding strength was 7.0 N/cm, the degree of water-repellency and water-repellency after washing were level three, the hydrostatic pressure was 41.0 KPa. This water-repellent finishing agent with simple synthesis process, good stability and excellent properties may be used in many fields.The innovation of this work is to use castor oil with three functional group and long hydrocarbon chain, self-made SN₂ and S₃N₂ as the materials. Therefore, the water-repellency was highly improved and the cost was also decreased.