Preparation Of Modified Nano-TiO₂/Acrylate Composite Emulsion And Its Application In Anti-ultraviolet Finishing Of Cotton Fabrics

Polyacrylate has wide application in textile finishing because of its simple production process,low production cost,excellent environmental performance and strong film-forming transparency and fabric adhesion.Cotton fabrics are soft and comfortable due to moisture permeability and permeability,but the UV resistance is poor,and Nano-TiO₂ has strong photocatalytic and antiultraviolet properties due to its high oxidation activity.In this paper,inorganic Nano-TiO₂ and organic acrylate emulsion were combined to prepare modified Nano-TiO₂/acrylate composite emulsion,which was used in the finishing of cotton fabric to improve the UV resistance of cotton fabric.In this paper,the sol-gel method was used to hydrolyze tetrabutyl titanate?TBOT?in ethanol solution to form Nano-TiO₂ sol,with controlling the hydrolysis rate by hydrochloric acid.Then,the surface of the Nano-TiO₂ sol was graft-modified with an appropriate amount of organosilane coupling agent KH-570,and its surface activity was changed from inorganic to organic.The lipophilicity of the Nano-TiO₂ sol before and after modification and its dispersion stability were compared.The effect of different amounts of HCl and KH-570 on the particle size of the NanoTiO₂ sol was studied by laser nanometer particle size analyzer.The results show that the TiO₂ sol produced increases rapidly with the increase of the amount of HCl and the amount of KH-570.When n?HCl?/n?TBOT?was 0.525 and n?KH-570?/n?TBOT?was 0.165,the Nano-TiO₂ sol produced had the smallest particle size of 18.3 nm.Characterization by infrared FTIR,XRD,TEM,FESEM.The results showed that KH-570 was grafted onto the surface of Nano-TiO₂,and its lipophilicity was improved.The prepared Nano-TiO₂ sol was anatase.The crystal form was unchanged but the degree of crystallization was higher with the increase of HCl dosage.The agglomeration effect of the modified Nano-TiO₂ sol is significantly reduced,with better dispersibility and smaller particle size.On this basis,methyl methacrylate?MMA?and butyl acrylate?BA?were used as soft and hard monomeric acrylic acid?AA?as functional monomers,and appropriate amount of modified Nano-TiO₂ sol was added to induce potassium persulfate.The modified Nano-TiO₂/acrylate composite emulsion was prepared by core-shell emulsion polymerization at a certain temperature.By testing the particle size,gel fraction and emulsion stability of the composite emulsion,the results show that the initiator,emulsifier and modified Nano-TiO₂ sol account for 0.5%,4%,1.5% of the total mass of the monomer,respectively.The smallest particle size and the best stability.The prepared composite emulsion was characterized by FTIR,SEM and TEM.The results showed that the modified Nano-TiO₂/acrylate composite emulsion was successfully prepared,and the composite emulsion latex particles had a core-shell structure.The prepared composite emulsion was finished onto the cotton fabric by the two-dip and twopressure process,and the fabric was finished with 1.5% modified Nano-TiO₂ composite emulsion.The finished fabric had a UPF of 103.12 and a T?UVA?of 3.25,T?UVB?is 2.54,the UV resistance is greatly improved,and has a good soaping resistance.By comparing the UPF values after finishing,the finishing process was optimized: baking time 3 min,baking temperature 120°C.The breaking strength and moisture permeability of the fabric before and after finishing were tested,indicating that the fabric after the composite emulsion finishing was not affected.