Synthesizing Gemini Surfactant With Ethylene Glycol Recycling Waste Polyester

With the development of the PET, the amount of the PET is increasing, there will be a result in wastage of resources and a lot of white pollution, if we don't recycle waste PET. So, the reseaech of resolving this problem has been a big object. The waste PET includes Waste PET fiber, waste PET bottle scrap, waste PET film, and so on. In this thesis, we use glycolysis to recycle the waste PET, and reuse it in to Gemini surfactant.This paper studied the glycol alcoholysis craft for waste PET 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℃, ethylene glycol and waste polyester fiber weight ratio was 1:4, the glycolysis time was 2h,and 0.5% zinc acetate was used as catalyst. PET was thoroughly glycolysed and the glycolysis conversion rate is 97.08%. The glycolysis products were analyzed by hydroxyland acid values and identified by different techniques, such as DSC, IR. The glycolysis predominant glycolysis product was BHET monomer, its purity reached 96% after crystallization depuration.The Gemini surfactant intermediate can be got by the substitute reaction of the BHET and chlorination.analyzed the influence of reaction temperature, the reaction time and the catalyst density to the reaction, and the products were characterized by IR, 1H-NMR.A series of biquaternaryammonium salt surfactants with ester bond were synthesized using waste polyester, ethylene glycoland, chlorination and N,N-demethyldodecylamine.The optimum reaction conditions, obtained by orthogonal experiment is that n(intermediate):n (N,N-dem ethyldodecylamine)=1:2.1 and The products were characterized by IR, melting point test and the surface properties. From the surface properties results, we can see that the critical micelle concent ration value is 1.47×10^-4mol/L and the surface tension value is 28.56mN/m.This paper analyzed the influence of different Gemini surfactant dosage to the rate of alkali dewelghting. It proved that alkali dewelghting can be the best.when the concentration of NaOH is 8g/L and the concentration of Gemini surfactant is 1.2g/L,the property of draping, breathing, water conserving can be improved a lot, while the PET fabric strength fall down.