次氯酸钠溶液对荧光增白剂的氧化

研究了次氯酸钠溶液对荧光增白剂CBS-X和31#的氧化作用、CBS-X和31#水溶液经紫外光老化过程,考察了荧光增白剂含量不同的洗衣液对黄变织物的增白作用。结果表明,CBS-X和31#都不能在次氯酸钠溶液和紫外光照下长期稳定存在,CBS-X与次氯酸溶液接触3.5 h或经紫外光照射96 h后在348 nm处不再具有吸收;31#与次氯酸钠溶液接触10 min或经紫外光照射96 h后345.5 nm处吸收峰消失,267 nm处生成新吸收峰。经荧光增白剂处理的织物经高质量分数次氯酸钠溶液洗涤易黄变,含质量分数0.2?S-X的洗衣液对被次氯酸钠溶液漂黄的织物增白效果较佳。

Oxidization of optical brightener in sodium hypochlorite solution

The oxidization of optical brighteners(OBs) CBS-X and 31# by sodium hypochlorite and the aging effect of these two OBs by ultraviolet light were studied.The brightening action of OBs to yellowish fabric by liquid laundry detergent containing different concentrations of OBs was investigated.The results showed that neither CBS-X nor 31# are stable in sodium hypochlorite solution or under long term exposure of ultraviolet light.The absorption peak at 348 nm of CBS-X disappears after it mixing with hypochlorite solution for 3.5 h or exposed in ultraviolet light for 96 h.The absorption peak at 345.5 nm of 31# disappears after it mixing with hypochlorite solution for 10 min or exposed in ultraviolet light for 96 h,while a new absorption peak at 267 nm occurs.The fabric treated by OBs is easy to turn yellowish after washing with sodium hypochlorite solution of high concentration.The liquid laundry detergent containing CBS-X has significant brightening effect on the yellowish fabric due to by sodium hypochlorite treatment.The optimum content of CBS-X in liquid laundry detergent is 0.2% by weight.