文献类型：期刊文献

中文题名：聚对苯二甲酸乙二醇酯固相缩聚过程乙醛脱除动力学

英文题名：Kinetics of acetaldehyde removal in solid-state polycondensation of poly(ethylene terephthalate)

作者：周舸旸[1];奚桢浩[1];赵玲[1]

机构：[1]华东理工大学化学工程联合国家重点实验室,上海200237

年份：2020

卷号：49

期号：11

起止页码：1076

中文期刊名：石油化工

外文期刊名：Petrochemical Technology

收录：CSTPCD;;Scopus;北大核心:【北大核心2017】；CSCD:【CSCD2019_2020】；

基金：十三五国家重点研发计划项目(2016YFB0303000);中央高校基本科研业务费专项基金项目(22221817014)。

语种：中文

中文关键词：聚对苯二甲酸乙二醇酯;乙醛;固相缩聚;扩散;动力学

外文关键词：poly(ethylene terephthalate);acetaldehyde;solid-state polycondensation;diffusion;kinetics

摘要：在小型薄层固定床中进行聚对苯二甲酸乙二醇酯(PET)固相缩聚实验,利用GC,DSC等方法考察了氮气流量、温度、粒径等因素对乙醛含量、Mn及端羧基含量的影响,建立了考虑乙醛生成、小分子扩散以及结晶度影响的PET固相缩聚过程乙醛脱除动力学模型,并模拟分析了PET颗粒内部的乙醛脱除行为。实验结果表明,在氮气流量5 L/min下脱除乙醛,可以排除外扩散影响。温度越高、粒径越小越有利于乙醛的脱除。端乙烯基缩聚与端羟基降解生成乙醛反应的活化能分别为127.54,166.70 kJ/mol,乙醛扩散活化能为48.72 kJ/mol。随反应的进行,乙醛含量沿径向从颗粒中心到颗粒表面不断减小,反应后期乙醛较难脱除。降低切片乙醛初始含量有利于乙醛脱除。
The solid-state polycondensation of poly(ethylene terephthalate)(PET)was carried out in a thin-layer fixed-bed reactor.The effects of the flow rate of N2,temperature and size of PET pellets on acetaldehyde concentration,Mn and carboxyl end group content were analyzed by GC,DSC,etc.A comprehensive particle kinetic model,involving main and side reactions,diffusion of small molecules,and crystallization,has been built.Based on this particle kinetic models,acetaldehyde removal behavior has been simulated.The result shows that the flow rate of N2 of 5 L/min can eliminate external diffusion.Increasing temperature and decreasing the size of PET pellets are beneficial to acetaldehyde removal.The activation energies of the polycondensation reaction of the vinyl end group and degradation of the hydroxyl end group for acetaldehyde formation are 127.54,166.70 kJ/mol,respectively.The diffusion activation energy of acetaldehyde is 48.72 kJ/mol.The acetaldehyde concentration decreases from the center of the PET pellet to the surface of the PET pellet radially.Acetaldehyde removal is more challenging at a later stage,and lower initial acetaldehyde concentration helps remove acetaldehyde.