Study On The Synthesis And Application Properties Of Aqueous Polyurethane Textile Finishing Agent

As solvent PU will not be in accord with developing trends of polyurethane for its high VOC, which is that countries all over the world increase and pay more attention to the environmental protection, and pollution laws are becoming stricter, the aqueous PU has emerged as the times required and has been developed quickly in the recent years. Cationic aqueous polyurethane is less reported than widely reported and produced anionic polyurethane. Cationic aqueous polyurethane that has unique properties have good future in textile industry, and its application as anti-crease finishing agent of cotton can improve elasticity of sample.In this paper, a kind of aqueous polyurethane dispersion was synthesized through step reaction polymerization from 1,6-hexamethylene diisocyanate, poly (1,3-butylene glycol adipate) 1 061/2 018/3 013, hydrophilic chain-extender of N-Methyl diethanolamine and blocking agent of caprolactam. Polyurethane emulsions are prepared by prepolymerization, reaction of chain extending, blocking rection, neutralization and emulsifying, and its proterties were studied carefully.The suitable synthesizing process was explored firstly by only using hydroxyl silicone and HDI as the raw materials. Then silicone- modified polyurethane was synthesized by blocking with PBAl 061, the proper ratio was investigated.The synthesis procesure was as follows. Poly (1,3-butylene glycol adipae) and 1,6-hexamethylene diisocyanae with nNCO/nOH at 1.9 reacted at 55℃for 120 min then up to 70℃for 30 min at prepolymerization. The temperature was lowered to 65℃as N-methyldiethanolamine was added keeping for 60 min at chain-extending reaction. The temperature was lowered to 60℃as caprolactam was added for 120 min at sealed end reaction. Followed by neutralization with acetic at 50℃for 10 min, finally distilled water was added and the mixted was stirring for 1 h.The synthesis procesure of silicone-modified polyurethane was as follows. The mixture of poly( 1,3-butylene glycol adipae) 1 061 /α,ω-diol terminated PDMS at 2.5 reacted with 1,6-hexamethylene diisocyanae at 60℃for 120 min then up to 70℃for 30 min at initial polymerization. The temperature was lowered to 65℃as N-methyldiethanolamine was added keeping for 60 min at chain-extending reaction. The temperature was lowered to 60℃as caprolactam was added for 60 min at sealed end reaction. Followed by neutralization with acetic at 50℃for 10 min, finally distilled water was added and the mixted was stirring for 1 h.The best finishing procedure was revealed as follows:a sample was padded once to 80%-85% pick up in a solution which contained PU of 50 g/L ,→dried at 80℃for 2 min→cured at 140℃for 3 min .The CRA(crease angle) of the cotton fibric treated with polyurethane were increased to 243°from about 205°.