醇碱联合解聚废聚酯的机理分析

Research on Mechanism of Depolymerizing Waster PET by Uniting the Ethandiol and the Luis Alkali

指出PET在EG和路易斯碱同时存在下 ,PET的解聚反应是醇解反应与碱解反应相互协同、互为促进的过程 ,其解聚速度与解聚率得到显著提高 ,解聚及回收TPA、EG工艺条件简化。实验表明在常压、180℃、30min内 ,PET解聚率可达 99% ,其解聚产物的颜色深浅主要受体系碱度、反应温度和反应时间的影响 ,通过选择不同的路易斯碱、调整解聚工艺条件可有效控制有色物质的生成总量。

The research shows that the depolymerizing reaction of waste PET is a synergetic and accelerated process that alcoholysis and alkaline hydrolysis act each other under the condition of excessive ethandiol and Luis alkali existing together.The enhancement of depolymerisation rate and depolymerizing speed are very remarkable.The process conditions of depolymerizing waste PET and recovery TPA and EG are oversimplified.The depolymerisation rate exceed 99% at the normal pressure and 180 ℃ in 15 min.The product of colored substance in depolymerizing system is affected by alkaline degree,reacting temperature and reacting time.It can be controlled effectively by choolsing different Luis alkali and adjusting the process conditions of depolymerisation.