关键词: 三苯乙烯基苯酚聚氧乙烯醚磷酸酯盐, 液体分散染料, 分散稳定性, 化学需氧量（COD）

Abstract: Liquid disperse dyes have become a research hotspot in recent years because they are able to meet the requirements of automation of printing and dyeing, batching systems, as well as energy saving in production. However, the liquid disperses dyes with a low dosage of dispersant are easy to be coarse and even coagulated and precipitated. In the process of immersion dyeing, the dispersion stability at high temperatures is poor, and the dye precipitates out, which leads to a problem of uneven dyeing and poor reproducibility. So, the dispersant is the key to preparing high-performance liquid to disperse dyes.
    The tristyrenylphenol polyoxyethylene ether (TSPOE-n) was esterified with phosphorus pentoxide, and hydrolyzed to obtain the tristyrenylphenol polyoxyethylene ether phosphate (TSPOEP-n; n=13, 16, 20 and 29), which was used as a dispersant for the liquidation of disperse dyes. The chemical structure of the dispersant was characterized by the infrared spectrum. The effect of ethylene oxide (EO) number in TSPOEP-n on the storage stability of liquid dispersed dyes was investigated by particle size analyzer, and the dyeing properties of liquid and powder disperse dyes were compared.
    The liquid disperse dyes prepared by dispersant TSPOEP-n (n=13, 16, 20 and 29) with EO numbers were all nanoscale and the average particle size was 175~215 nm. The PDI was about 0.2, and the absolute value of Zeta potential was greater than 25 mV. After 100 days of storage, when the EO number was 13, 16, 20, and 29, the dispersed dye particle size increased by 35.3, 20.2, 34.4, and 58.8 nm, respectively. Disperse dyes' particle size and distribution tended to be stable. And the average particle size was less than 350 nm, which could meet the dyeing requirements. After the dispersed dyes were heat treated at a high temperature (130 ℃) and filtered by double-layer filter paper, there were a small number of dye particles on the filter paper and the dye filtration time (stage)/residue rating (stage) reached C/3 or above. When the dye mass fraction was 1%~5%, the unevenness of the fabric dyed by liquid disperse dye was slightly higher than that of the sample dyed by powder dye. In addition, with the increase in the amount of the liquid dye, the unevenness decreased while the dye evenness improved significantly. On the other hand, When the dye mass fraction was greater than 2% and the dyeing unevenness value was less than 0.05, which indicated good dyeing evenness. Also, the COD of the residual liquid of liquid disperse dye was about 35.7% lower than that of powder dye.  
    The tristyrenylphenol polyoxyethylene ether phosphate (TSPOEP-n) obtained from the esterification and hydrolysis of phosphorus pentoxide was used as the dispersant for the grinding and fluidization of dispersed blue 79. The results show that when n values were 13, 16, 20, and 29, the dispersant prepared has high dispersion and the stability efficiency for dye particles is significant. The average particle size of the four liquid disperse dyes is less than 215 nm. During normal temperature storage, the particle size of liquid disperse dyes tends to be stable at about 100 days, and the dyes have good high-temperature dispersion stability. When TSPOEP-16 is used as a dispersant, the particle size increase of dyes stored at room temperature is only 20.2 nm, and the dye uptake is significantly higher than that of powder disperse dyes. The COD of the dye residue after dyeing is reduced by 35.7% compared with that of powder dyes.

Key words: tristylphenol polyoxyethylene ether phosphate, liquid disperse dye, dispersion stability, chemical oxygen demand(COD)