Research On A New Green Printing And Dyeing Method Based On Radiation Graft Polymerization Modified Cotton

The composition of modern daily necessities is inseparable from textiles,and dyeing is a critical and complex process in the production process of textiles.At present,when dyeing textiles in the industry,it is necessary to add various printing and dyeing auxiliaries such as acids,alkalis,salts,etc.to assist in dyeing to improve the dye uptake,resulting in wastewater components generated in the process of textile printing and dyeing.It is complex and difficult to handle,which seriously affects the ecological balance and human health.Therefore,the main research topic of this paper is to improve the dyeing properties of cotton fabric by radiation grafting,enhance the binding force between the cotton fabric surface and the dye,so as to improve the dye uptake rate and reduce the waste water pollution without using printing and dyeing auxiliaries.This thesis first studied the grafting of Polydimethylaminoethyl methacrylate onto the surface of cotton fabric by radiation grafting,and studied the effect of monomer concentration and absorbed dose on the degree of grafting,so that the surface of cotton fabric had tertiary amine groups.Secondly,the modified cotton fabric was colored with negatively charged acid dye.The tertiary amine was easily protonated in the acid dye solution and was positively charged.The modified cotton fabric was combined with the acid dye through electrostatic adsorption.Then the thesis analyzed its dyeing performance by changing the dye concentration,dyeing time,and dyeing temperature.Analyze the dyeing wastewater produced by it.This thesis provides a basis for the radiation graft modification of cotton fabric and industrial printing and dyeing to reduce wastewater pollution.The specific research content and results are as follows:(1).Study on the kinetics of radiation grafting on cotton fabricIn this paper,Polydimethylaminoethyl methacrylate was irradiated grafted and fixed on cotton fabric.As the absorbed dose did not change,the monomer concentration rose from 5% to 40%,the grafting rate increased from 1.4% to 5.4%;the monomer concentration did not change.As the absorbed dose increased from 10 k Gy to 50 k Gy,the grafting rate decreased from 6.2% to 4.5%.Infrared test,thermogravimetric test,scanning electron microscopy test,elemental analysis and X-ray photoelectron spectroscopy showed that Polydimethylaminoethyl methacrylate was successfully grafted onto cotton fabric,and a covalent network system was formed between it and cotton fiber.The cotton fabric had been successfully cationic modified.(2).Dyeing of acid dyes on radiation grafted modified cotton fabricUse Acid Red 18,Acid Blue 9,Acid Yellow 23,and Acid Black 1 to color the cationic modified cotton fabric.The sulfonic acid groups contained in the acid dyes attract each other with the amino groups on the surface of the modified cotton fabric,making the dye fixed on the cotton fabric.Infrared test and scanning electron microscope test show that the dye was evenly distributed on the surface of the cotton fabric;Lab value analysis of chromaticity showed that the dye uptake rate could be changed by changing the dye concentration,dyeing time,and dyeing temperature,thereby controlling the color change of the cotton fabric.The ?E value indicated that the dyeing was even.The color fastness of the colored cotton fabric was tested,and the result was that the color fastness to dry rubbing was grade 4-5,and the color fastness to wet rubbing was grade 2-3.After 20 accelerated washing cycles,the color of the cotton fabric surface was still uniform.The p H value,COD value and TSS value of dyeing wastewater had reached the international and domestic printing and dyeing wastewater discharge standards and could be directly discharged.