涤纶化学降解单体产物的高效结晶提纯研究  

Efficient Purification of the Glycolysis Monomer of Polyester Enabled by Its Unique Phase Transition Property

作　　者：鲍青青 孙海钰 陈卓 官军 朱美芳[1] 陈龙[1] 左伟伟[1] Qing-qing Bao;Hai-yu Sun;Zhuo Chen;Jun Guan;Mei-fang Zhu;Long Chen;Wei-wei Zuo(State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,College of Materials Science and Engineering,Donghua University,Shanghai 201620;Zhejiang Jiaren New Material Co.,Ltd,Shaoxing 312000)

机构地区：[1]纤维材料改性国家重点实验室东华大学材料科学与工程学院,上海201620 [2]浙江佳人新材料有限公司,绍兴312000

出　　处：《高分子学报》2023年第3期346-355,共10页Acta Polymerica Sinica

基　　金：国家重点研发计划(项目号2020YFC1910300、2020YFC1910301);东华大学中央高校基本科研业务费专项资金(项目号2232022A-02)资助项目.

摘　　要：为了解决废旧涤纶(PET)纺织品乙二醇醇解法循环利用中存在的醇解产物对苯二甲酸二乙二醇酯(BHET)纯化困难的问题,通过研究BHET晶体的独特的相变性质,发展了BHET纯化新技术.实验结果表明,对结晶的、醇解反应产物BHET使用减压升华操作,在1.33 kPa,130℃的条件下,可获得纯度达99.7%,收率达86.4%,白度(L*值)达99.8的纯化BHET.回收所得的BHET可再缩聚制备再生PET.该再生PET在相同条件下与由石油基BHET缩聚所制得的PET具有类似的性质,包括白度、分子量及分子量分布等.本文还验证了该种醇解法回收废旧涤纶纺织品的技术的普适性:考察各种含有不同成分及颜色的涤纶纺织品样品的醇解行为及产物分离纯化效果.所研究的BHET纯化方法步骤短、产物纯度高、不额外使用有毒化学试剂,并有效地克服了粉末状BHET在加热纯化时容易发生缩聚的关键难题,为高品质回收废旧涤纶纺织品提供了一种新的路径.To overcome the difficulties of purification and decolorization of bis(2-hydroxyethyl)terephthalate(BHET)that is associated with the recycling of wasted polyester(PET)textiles,this work studies the unique phase transition behavior of crystalline BHET in hope to find new and efficient purification strategies of the glycolysis product monomer of PET.With sublimation in vacuum,pure and decolorized BHET can be obtained with yield of up to 86.4%,purity of up to 99.7%and whiteness(L*value)of up to 99.8,respectively.Repolymerization of the obtained purified BHET afforded recycled PET,which possessed similar properties with respective to the PET derived from petroleum-based BHET,including molecular weight,the distribution of molecular weight and whiteness,respectively.The effectiveness of this recycling strategy of wasted polyester textile was also verified by evaluating a series of PET samples,including PET textile blends and the real wasted polyester textiles that were picked from waste bins.This purification strategy of BHET requires less purification steps,affords high purity of the product,obviates the uses of toxic chemicals,avoids the high propensity of BHET powders to polycondensation under the commonly purification conditions and will provide a new strategy for high-quality recycling of waste polyester textiles.

关 键 词：废旧涤纶纺织品回收 对苯二甲酸二乙二醇酯纯化 废旧涤纶脱色 乙二醇醇解法 

分 类 号：TQ245.24[化学工程—有机化工] X705[环境科学与工程—环境工程]