Research On Water-repellent And Antibacterial Finishing For Worsted Fabrics

With the development of people’s living standard,functional textiles have been paid more and more attention.Because of comfort and warmth,exquisite and novel features worsted fabrics favored by consumers.Wool fiber,as a kind of protein fiber,can easily cause the growth and multiplication of bacteria.And wool fabrics are used to make high-grade suits and jackets,they usually need dry cleaning in order to avoid water fade and deformation.Therefore,it is necessary for wool fabrics to carry out water repellent and antibac terial finishing.The sol-gel technology can be used for the water repellent finishing of worsted wool fabric,and can also be used for antibacterial finishing.In addition,it has flexible process and easy control.Therefore,the silica sol can be prepared by sol-gel technology,which can be used for water repellent and antibacterial finishing of worsted fabrics.Most of the traditional silica sol was prepared by using TEOS as the precursor,it usually needs organic solvent such as ethanol,it is high-cost,flammable and not conducive to safe production.Therefore,it has broad industrial prospects in the preparation of silica sol by using alcohol free sol-gel system.It is of great practical significance to realize the functional finishing of wool fabrics by using the sol-gel technology to combine the water repellent and antibacterial finishing.In this paper,water as the solvent,methyltrimethoxysilane（MTMOS）as the precursor and under application of surfactant and catalysts,modified SiO₂ hydrosols were prepared by adding water-repellent agent and antibacterial agent for worsted fabrics treated by water-repellent and antibacterial finishing.At the same time,wool fabrics were pretreated by citric acid in order t o improve the adsorption of the sol in the worsted fabric surface.In order to improve the washing fastness of the fabric after finishing,the silane coupling agent（KH560）was added to improve the adhesion of the film on the surface of the fabric s.First of all,the influences of different concentrations of citric acid pretreatment on wool fabrics whiteness,crease resistance,static contact angle of fabrics dipping SiO₂ hydrosol were discussed.And fabrics pretreated by citric acid surface morphology and group transformation were analyzed by using scanning electron microscopy（SEM）and Fourier transform infrared spectroscopy（FTIR）.The optimal concentration of citric acid pretreatment for 60g/L,the whiteness of the treated fabric was slightly increased,but the difference is very small.The wrinkle recovery angle and the static contact angle of fabrics dipping SiO₂ hydrosol have reached the best.Secondly,two kinds of antibacterial agents,chitosan and poly guanidine,were selected to be used in SiO₂ hydrosol water repellent and antibacterial finishing.In one step of chitosan water repellent and antibacterial f inishing,the inf luences of methyltrimethoxysilane（MTMOS）,hexadecyltrimethoxys ilane（HDTMS）,sodium dodecyl benzene sulfonate（SDBS）,NH₃﹒H₂O,chitosan and other factors on the water-repellent and antibacterial finishing of fabrics were discussed by using the single factor analysis.And the optimal static contact angle and water repellency rating of the finished fabric can obtained 140.4°and 100.The water repellent effect is excellent,but the antibacterial effect is poor and unable to meet the requirements.In one step of poly guanidine water repellent and antibacterial finishing,the optimal water repellent process of SiO₂ hydrosol was obtained by orthogonal design.And the optimal static contact angle and water repellency rating can obtained 148.6°and 100.When adding poly guanidine 4%（owf.）in the optimal water repellent process,the antibacterial rate of the fabric to Staphylococcus aureus was100%,and the inhibition rate of Escherichia coli was about 31.9%.But the static contact angle and water repellency rating are 145.8°and 90.The water repellent property slightly declined.The antibacterial properties of the fabric had little effect on the water repellency of the fabric.Finally,the effect of KH560 addition on the washing fastness of wool fabrics was discussed,and the surface morphology of wool fabrics was observed by scanning electron microscopy（SEM）.When the KH560 content is 1m L,after washing 10 times,the static contact angle is 147.9°,water repellency rating is 70,inhibition rate of Staphylococcus aureus is 74.77%.The fabric durability is better than other fabrics.