Synthesis And Application Of Fluorine-free Water-proofing Agent Based On Hyperbranched Polyester

As we all know,perfluoroalkyl(side chain Rfn,n?8)is widely used to synthesize a variety of water-repellent and oil-repellent finishing agents.Unfortunately,studies have shown that long-chain fluoride has certain toxicity,bioaccumulation and durability to human body,which has been restricted and banned by many countries.In order to solve this problem,a fluorine-free water-repellent agent based on hyperbranched polyester was synthesized and applied to polyester fabric.The research and results are as follows:(1)Alkyl-modified hyperbranched polyester(H20-n)was synthesized using hyperbranched polyester,triethylamine and lauroyl chloride.The optimized synthesis process of H20-8 is as follows:Molar ratio of H20 with lauroyl chloride is 1:8,Molar ratio of lauroyl chloride with triethylamine is 1.0:1.1,the reaction temperature is 25 C,the reaction time is 1.5 h,the yield is 85.7%,the product is light yellow waxy;Graft-modified fluorine-free water repellent finishing agents was synthesized using H20-8,isophorone diisocyanate,polytetrahydrofuran(Mn=1000),2,2-dimethylpropionic acid and 1,4-butanediol.The optimized synthesis process of WPUH20-8 is as follows:H20-8,DMPA and BDO respectively 10%,5%and 2%in the process of the quality of polymers,R=1.3,the reaction temperature is 65 ?,reaction time is 6 h.The structure of the product was characterized by infrared spectroscopy.The average particle size of the emulsion was 111.4nm and Zeta potential was-38.4mV.Application of WPUH20-8 on the polyester fabric,when the dosage of the WPUH20-8 to 150 g/L,finishing liquid pH=7?8,curing temperature and time at 160? and 2 min respectively,after WPUH20-8 finishing of polyester fabric contact angle is 128.4°,waterproof rating of 90,ventilation rate is 20.86 mm/s,whiteness of 73.5%.(2)Blocked polyurethane(BWPU)was prepared from PEG,DMPA,TDI and methyledone oxime as raw materials,DMF as solvent and TEA as neutralizer.H20-8 was emulsified with span-80 and tween-80 as emulsifiers.The optimized emulsification process is as follows:With 50%of Span-80 and 50%Tween-80 of a two-component emulsifiers emulsify H20-8,dosage of emulsifier 30%of H20-8 quality,emulsifying temperature and time of 50? and 20 min respectively.The obtained milky white H20-8 emulsion has particle size of 0.198 m and Zeta potential of-10.3mV without stratification(30d).The influence of H20-8 emulsion content on the stability,water absorption of the blend modified fluorine-free water-proofing agent(BWPU/H20-8)and the properties of the finished fabric were discussed.The results were as follows:When the content of H20-8 emulsion is in the range of 0?25%,BWPU/H20-8 has good stability,the water absorption rate of the film tends to be stable in the range of 15%.The finished fabric has the best water repellency.The air permeability and whiteness of the finished fabric with H20-8 emulsion content in the range of 5?20%are not different from those of the original fabric.Application of WPUH20-8 on the polyester fabric,when finishing liquid mass concentration of 150 g/L,finishing liquid pH=7?8,curing temperature is 160?,the curing time of 3 min,after WPUH20-8 finishing of polyester fabric contact angle is 130.2°,waterproof rating of 90,ventilation rate is 20.08 mm/s,whiteness of 66.5%.The retention rates of contact angle and water-repellent grade were 90.93%and 94.44%,respectively,after 15 times of washing,while the air permeability and whiteness were slightly improved,and the surface friction coefficient(MIU)and surface roughness(SMD)were slightly changed,indicating that the polyester fabrics treated with the blend modified fluorine-free water-repellent agent had good washing resistance.