碱性深共晶溶剂催化醇解乙烯-醋酸乙烯共聚物研究  

Study on Alcoholysis of Ethylene-vinyl Acetate Copolymer Catalyzed by Alkaline Deep Eutectic Solvents

作　　者：丁晓艳 李晓佩 张勇杰 胡雁鸣 DING Xiao-yan;LI Xiao-pei;ZHANG Yong-jie;HU Yan-ming(School of Textile and Material Engineering,Dalian Polytechnic University,Dalian 116034,China;Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China)

机构地区：[1]大连工业大学纺织与材料工程学院,大连116034 [2]中国科学院大连化学物理研究所,大连116023

出　　处：《高分子通报》2023年第12期1691-1698,共8页Polymer Bulletin

摘　　要：截至目前,工业化生产乙烯-乙烯醇共聚物(EVOH)主要通过乙烯-醋酸乙烯共聚物(EVA)的醇解反应。然而,EVOH生产过程中伴随大量废水的产生,不可避免地会引起环境问题。本文合成了一系列的碱性深共晶溶剂,并将其用于催化醇解EVA。系统研究了深共晶溶剂结构与催化性能的关系,以及醇解反应参数、EVA结构组成和氮气流辅助对醇解效率的影响。研究表明,碱性越强的深共晶溶剂,EVA的醇解效率越高。其中,1,8-二氮杂二环十一碳-7-烯/苯甲醇(DBU-BA)表现出了优异的催化活性,在极低的催化剂用量下,即可得到醇解度接近100%的EVOH产物。此外,DBU-BA可以重复使用至少5次,催化活性没有明显降低,表现出优异的可重复使用性。基于核磁共振氢谱(1H-NMR)和傅里叶红外光谱(FTIR)分析,本文揭示了深共晶溶剂在EVA醇解体系中可能的催化机理。Industrial ethylene-vinyl alcohol copolymer(EVOH)is mainly prepared by alcoholysis of ethylenevinyl acetate copolymer(EVA)up to now.However,a large amount of wastewater will be produced during the preparation of EVOH,which inevitably results in a series of environmental problems.Herein,a series of alkaline deep eutectic solvents(DESs)were synthesized and used as eco-friendly catalysts for alcoholysis of EVA copolymer.The structure and catalytic performance relationship of DESs and the effects of the reaction parameters,EVA composition,and nitrogen flow on the alcoholysis were systematically investigated.The DESs with higher basicity were more efficient for the methanolysis of EVA,and among them,1,8-diazabicyclo[5.4.0]undec-7-ene/benzylalcohol(DBU-BA)exhibited excellent catalytic activity and afforded EVOH with nearly 100%of alcoholysis degree at very low catalyst loadings.Moreover,DBU-BA could be reused at least five times without the decrease of catalytic activity,showing excellent reusability.On the basis of proton nuclear magnetic resonance(1H-NMR)and Fourier transform infrared spectroscopy(FTIR)analyses,the plausible mechanism of DESs catalyzed alcoholysis of EVA was proposed.

关 键 词：乙烯-乙烯醇共聚物 深共晶溶剂 醇解 催化 可重复使用性 

分 类 号：O621.251[理学—有机化学]