Synthesizing Polyester Size With Ethylene Glycol Recycling Waste Polyester Fiber

Chemistry recycling waste poly(ethylene terephthalate) (PET) has received very much attention at present. Among chemistry recycling the glycolysis has prominent industrialization prospect. People put much attention to recycle polyester bottle, but very few to research recycling the polyester fiber. The molecular weight and the intrinsic viscosity are different. The craft of glycol alcoholysis recycle polyester bottle is not suitable for the waste polyester fiber especially.This paper studied the glycol alcoholysis craft waste polyester fiber, analyzed the influence of reaction temperature, the reaction time and the catalyst density to the alcoholysis craft, The best glocoholysis craft is: at 196~198°C, ethylene glycol and waste polyester fiber weight ratio was 4, the glycolysis time was 2h,and 0.5% zinc acetate was used as catalyst. PET was thoroughly glycolysed and the glycolysis conversion rate is 98.06%. The glycolysis products were analyzed by hydroxyland acid values and identified by different techniques, such as DSC, IR, HPLC. The glycolysis predominant glycolysis product was BHET monomer, its purity reached 96% after crystallization depuration, and the glycolysis products also include some dimmer and trimer.Using glycolysis product BHET which was through simple depuration as substrate, adding DEG and SIPA as modified monomers, The polyester size could be synthesized by ester exchange, esterification-polycondensation. It was verified that the obtained polyester size are water-soluble.. Polyester size was characterized by IR. And the results show that the polyester size was makeup of them.The film of its mixed size with starch size was studied. Breaking strength, rupture elongation, wear resistance and moisture absorption was researched. The result indicates that polyester size have low viscosity and better thermo-bonding stability; The solution system of Polyester size/acid-degraded starch mixtures size was stability and the mixture size has good property of the breaking strength, the breaking elongation and the abrasion resistance.