| Coating dyeing(i.e.pigment printing and dyeing)has a lot of good characteristics such as simple process,less water consumption,low pollution,suitable for all kinds of fiber and so on,as a result,coating dyeing has a very broad application prospect in textile processing.The structure and performance of adhesive has a decisive influence on the quality of coating dyeing products.The coating adhesive used in today is the fourth generation self-crosslinking polyacrylate adhesive,which is easy to release formaldehyde in the storage or use and to be yellowing and sticky under the high temperature.Aiming at the existing problem of polyacrylate adhesive,the paper chose monomers and optimum reaction conditions,then prepared two kinds of environmentalfriendly adhesives.One was non-formaldehyde of pure polyacrylate adhesive,another was gelatin protein modified polyacrylate adhesive.The structure and performance of adhesive ware characterized and application process was optimized.Finally,the application effect of adhesive was compared and evaluated by applying the two kinds of adhesives to the coating dyeing of cotton fabric.The purpose of this paper was to produce a high-quality and environmental-friendly adhesive which could adapt to the demand of the rapid development in coating dyeing industry.The paper selected non-formaldehyde glycidyl methacrylate(GMA)as the functional monomer and reactive emulsifier DNS-86 as emulsifier to prepare polyacrylate adhesive(PA).The synthesis process was optimized as follows: butyl acrylate(BA):methyl methacrylate((MMA):styrene(ST)=10:3:2,emulsifier dosage is 4%(total monomer mass,after the same),ammonium persulfate as the initiator and its dosage is 1%-1.2%,GMA dosage is 4.5%,temperature to 80℃ and begin to adding pre-emulsion dropwise with the speed of one drop per second,then heat preservation time is 30min-60 min.After that,the paper modified the gelatin by Alkali degradation and epichlorohydrin modification and got the modified gelatin containing epoxy group.Then adding the modified gelatin to the emulsion polymerization system and reacting with acrylic monomers,the environmentalfriendly adhesives which namely gelatin grafted polyacrylate adhesive(GPA)was obtained.The process of gelatin modification was optimized through experiment as follows:water-gelatin ratio is 2:1 to get gelatin solution,and adding Na OH whose dosage is 8%(gelatin quality,after the same),degradation in 60℃ for 30 min,then up to 80℃,drops 2%epichlorohydrin,continue to react for 40min-60 min and discharging.The synthesis process of adhesive GPA was optimized: take 3% modified gelatin(relative to the total monomer mass)to emulsion polymerization and react with acrylic monomers,then the emulsion is the target product.The performance of adhesive PA and GPA was tested and characterized.Results showed that modified gelatin on adhesive GPA did have been grafted with acrylic monomers by emulsion polymerization.Compared with the emulsion performance of adhesive PA,the particle size and PDI of adhesive GPA was smaller,which could help improve the dispersion stability of the emulsion.What’s more,GPA was not easy to loss water and form film on standing,while fast film forming under the high temperature curing.This was conducive to avoid the plugging occur in coating dyeing.In terms of the properties of film,the elongation at break of GPA film was nearly two times of PA film,but the breaking strength was slightly lower than that of PA film.Compared with the applications of adhesive PA in coating dyeing,the adhesive GPA could make the coating dyeing products obtain better friction fastness and fastness to soaping,but handle was slightly down.Therefore,the preparation of adhesive GPA in paper had a better performance than polyacrylate adhesive PA.Adhesive GPA could not only improve the color fastness of products,but also solve some problem in the coating dyeing process,such as plugging net,sticking roll,and so on. |
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