| The weight of waster PET is increasing quickly with the rapid development of polyester industry.The polyester waste recycling and reuse have great significance for easing world oil crisis and reduce waste pollution to the environment.Chemical method was one of advantaged ways to recycling the waste polyester. It included hydrolysis, methanolysis,mellow alkali treatment,Alcoholysis with Ethylene Glycol. Among chemistry recycling the glycolysis has prominent industrialization prospect.In this paper,the material is waster PET. Scrap of non-ferrous polyester was depolymerized through glycolysis using ethylene glycol. Glycolysis product was separated and purified. The influences of m(EG) /m(PET),temperature,the reaction time and amount of catalyst on conversion rate were investigated. If at m(EG)/m(PET)=2, 196℃, the glycolysis time was 3h and 0.5% catalyst, PET was thoroughly glycolysed and the glycolysis products was obtained with the hydroxyl number values above 434mg/g. Bis-2- hydroxyethyl terephthalate(BHET) monomer and its oligomers were predominant glycolysis product. The products were characterized by IR spectrum, DSC, HPLC and 1H-NMR.The content of purified BHET is 97%.Using glycolysis product BHET which was through simple depuration as substrate. And get DMT by transesterification using methanol. The influences of m(methanol) /m(BHET),temperature and the reaction time on reaction were investigated. If at m(methanol)/m(BHET)=2, 65℃and the glycolysis time was 3 h, DMT and EG was pure. 1,4-benzenedicarboxylic acid,dimethyl ester (DMT) monomer was predominant product. The products were characterized by IR spectrum, DSC, GS/MS. The content of purified DMT is 99.42%. |
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