The Preparation Of New Dyeing Promoter And The Study Of Its Application On Polyester

A mass of consumption of the dyed polyester fabrics and its blends is because of excellent performance of polyester.However,the polyester fabrics dyed by high temperature-pressure dyeing method have many problems such as high energy consumption,high requirement for the equipment and not suitable for its blends,and the conventional carrier dyeing method has negative effects on the environment.The purpose of the project is to improve the dyeing performance of disperse dyes on polyester fabrics and reduce dyeing temperature.In this paper,the cationic benzene ester additive was synthesized by phthalic anhydride with self-made WLS,a cationic crosslinking modifier,and mixed with N-butyl phthalimide at a mass ratio of 2:1,and then compounded with appropriate anionic and nonionic surfactants to prepare an dyeing promoter,which was applied to the process of polyester boiling dyeing under normal pressure.In this paper,the dye uptake ratio,the apparent depth K/S and the color fastness of the dyed fabric were used as the evaluation indexes.Effects of the mass ratio of phthalic anhydride to WLS,the amount of catalyst and the synthesis temperature and time on the dyeing properties of polyester boiling dyed by disperse dyes under normal pressure were studied.The optimal synthesis conditions of the cationic benzene ester additive were determined,and the structure and properties of the additive were characterized and analyzed.The results showed that the benzene ester additive synthesized in the study had cationic quaternary ammonium structure and ester structure,and was the target product.In order to further enhance the accelerating effect of the benzene ester additive,it was compounded with N-butyl phthalimide and anionic and nonionic surfactants in a certain proportion to obtain the dyeing promoter of polyester.Then the optimal application process of the dyeing promoter in polyester boiling dyed by disperse dyes under normal pressure was determined and the dyeing effects were compared with that of the conventional dyeing process at high temperature and high pressure.The results showed that in the boiling dyeing process of polyester under normal pressure with the dyeing promoter,the dye uptake ratio,the apparent color depth,the shade and dyeing levelness of the fabrics dyed by different kinds of disperse dyes and the rubbing fastness and soaping fastness of the fabrics dyed by disperse black ECT were close to that of conventional dyeing process athigh temperature and high pressure,and significantly better than the dyeing process under normal pressure without the dyeing promoter.But the color fastness of polyester fabrics dyed by other kinds of disperse dyes under normal pressure with the dyeing promoter was slightly lower than that of conventional dyeing process at high temperature and high pressure.Compared with the dyeing process under normal pressure without the dyeing promoter,the dyeing promoter can improve dyeing permeability and migration properties of polyester fabrics dyed by disperse dyes.The phenomenon indicated that the dyeing promoter had good promotion effect.But the dyeing permeability of the dyeing process under normal pressure with the dyeing promoter was not as good as that of conventional dyeing process at high temperature and high pressure.The boiling dyeing process of polyester fabrics under normal pressure with the dyeing promoter had the advantages of low dyeing temperature,short dyeing time,low energy consumption and low COD of dyeing wastewater,and met the requirement of energy saving and emission reduction.The mechanism of the dyeing promoter in boiling dyeing process of polyester under normal pressure was studied.It was found that the dyeing promoter can improve the solubility of the refined disperse dyes,reduce the glass transition temperature,melting temperature and crystallinity of polyester,and improve the dyeing properties of polyester.And the dyeing promoter had no effect on the main structure,strength and heat resistance of polyester.But the dyeing promoter decreased dispersion stability of the disperse dyes in dye bath.The effects of the dyeing promoter on the dyeing kinetics and thermodynamics of polyester dyed by disperse black ECT were investigated.It was found that compared with the boiling dyeing process under normal pressure without the dyeing promoter and the dyeing process at high temperature and high pressure,the boiling dyeing process under normal pressure with the dyeing promoter can improve the dyeing rate constant and the diffusion coefficient of the disperse black ECT dyeing on the polyester,shorten the half-dyeing time,increase the partition coefficient K,the affinity of the disperse dye to polyester and the absolute value of negative value of the dyeing heat,and reduce the degree of reduction of dyeing entropy.However,the adsorption mechanism of the disperse dyes on the polyester fabrics in the boiling dyeing process under normal pressure with the dyeing promoter had not changed,and still belonged to the adsorption of Nernst distribution type.Thus,the dyeing promoter can plasticize polyester fabrics to increase the adsorption force of disperse dyes on the fiber surface and to improve the diffusion rate ofthe disperse dyes to the fiber interior.This study is in line with the requirements of the development of environmental protection,so this is an important research topic.