亚临界水条件下废旧涤棉混纺织物的分离

Separation of Waste Polyester-cotton Blended Textile under Subcritical Water Condition

摘要:

涤棉的性能差异导致废旧涤棉混纺织物回收再利用困难。本文利用棉纤维和涤纶不同的耐酸性，结合亚临界水的特性，采用水热法对废旧涤棉混纺织物的分离回收进行研究。以涤棉混纺比为80/20废旧涤棉织物为研究对象，HCL为催化剂，研究了水热温度、反应时间及盐酸浓度对分离过程的影响，并对水热反应后产物的物化性能进行了表征。结果表明：在水热温度150℃、反应时间3 h，盐酸浓度为1.5%的水解条件下，废旧涤棉混纺织物中的涤棉组分分离效果良好。混纺织物中棉纤维发生水解，一部分形成固体纤维素，产率为48.21%左右；其余水解生成水溶性糖类物质；水热处理后的涤纶纱线回收率高达96%，断裂强度小幅降低3%，仍可直接再次使用。含有水溶性糖类的水解液可循环使用5次，实现了废旧涤棉混纺织物的高值化、绿色化回收利用。

Abstract:

he performance difference between polyester and cotton makes the recycle and reuse of the waste polyester-cotton blended textiles is complex. In the paper, hydrolysis method was used to the separation and recovery of waste polyester-cotton blended fabric, considering the different acid resistance of cotton fiber and polyester fiber and the characteristics of subcritical water. The effects of hydrothermal temperature, reaction time and hydrochloric acid concentration on the separation process were studied by using the polyester/cotton blended ratio of 80/20 waste fabrics as the raw material and HCL as catalysts, then the physicochemical properties of the products after hydrothermal reaction were characterized. The results indicated that the suitable hydrothermal process can be determined as follows: catalyst concentration of 1.5%, hydrothermal temperature of 150℃, and the reaction time is 3 h.The cotton fiber in blended fabric was hydrolyzed, and some of them hydrolyze to solid cellulose, the yield is about 48.21%; the other continues to hydrolyze to water-soluble carbohydrate. The recovery rate of polyester yarn after hydrothermal treatment is up to 96%, and the fracture strength is just reduced by 3%, which can be used directly. The hydrolysate containing water-soluble sugars can be recycled 5 times, which realizes the high value and green recycle of the waste polyester/cotton blended fabric.