Anionic and nonionic surfactants with good permeability were added in the bleaching process

2020-11-11 16:35:15

When the surfactant is added into the liquid, even if the concentration is very small, it will spontaneously cause a strong reduction of the surface or interfacial tension. Surfactants are amphoteric in structure. One end of the surfactant is hydrophilic and the other is hydrophobic. The amphoteric molecules will self orientate on the surface of the solution, the polar groups extend to the water, while the hydrophobic hydrocarbon groups extend to the air or oil interface, thus reducing the surface tension of the liquid. Surfactants can emulsify, disperse, solubilize, moisten, foaming, defoaming, lubricating, washing, softening, antistatic and anti-corrosion.

The pulping process is to separate lignin, hemicellulose, resin, pigment and ash from cellulose as much as possible. The role of surfactant is to separate impurities and purify cellulose. In the process of producing man-made fibers, surfactants are often added in the alkali impregnation of pulp. This is achieved by the dispersion and washing effect of surfactants to remove the resin.

Uniform bleaching effect can be obtained by adding anionic and nonionic surfactants with good permeability in bleaching process. In addition, the addition of sodium alkyl benzene sulfonate and nonylphenol polyoxyethylene ether in the process of pulp washing can also obtain good washing effect. In addition, surfactants are widely used in waste paper deinking, paper sizing, blanket washing and paper coating coating dispersant.

In recent years, double chain quaternary ammonium salt disinfectants with one hydrophilic group and two lipophilic groups have been newly developed, which has better gelling speed, stronger ability to reduce surface tension, and can increase their water solubility. Even when the water quality is hard, it also shows good solubility and good stability. The results show that the bactericidal effect of double chain quaternary ammonium salt disinfectant is superior to that of single long chain quaternary ammonium salt, with better decontamination ability, high temperature resistance and low toxicity. There are three kinds of new products on the market in China: Baidusha, also known as Didecyl dimethyl ammonium bromide; Xinjieling disinfectant, also known as bis (dodecyldimethyl) ethylenediammonium bromide; lierkang 1210 disinfectant, a compound disinfectant composed of Didecyl dimethyl ammonium chloride and N-alkyl (50% C14, 40% C12, 10% C16) dimethylbenzyl ammonium chloride.