结晶性脂肪族聚碳酸酯催化解聚研究  

Catalytic Depolymerization of Crystalline Aliphatic Polycarbonates

作　　者：林旭名 王明倩 傅晓艳 丁志强 王彬[1] Xu-ming Lin;Ming-qian Wang;Xiao-yan Fu;Zhi-qiang Ding;Bin Wang(School of Materials Science and Engineering,Tianjin University,Tianjin 300350)

机构地区：[1]天津大学材料科学与工程学院,天津300350

出　　处：《高分子学报》2024年第11期1476-1486,共11页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号52222302)资助项目.

摘　　要：结晶性脂肪族聚碳酸酯的晶区结构严重阻碍溶剂和催化剂的渗透,降低解聚反应活性.其热解聚反应过程也往往十分复杂,常常伴随着诸多副反应,无法高选择性回收目标产物.本文工作研究了不同催化剂、反应条件下的聚(碳酸丁二醇酯)、聚(碳酸戊二醇酯)以及聚(碳酸己二醇酯)的本体熔融解聚反应与解聚行为,并通过核磁氢谱测定了产物选择性差别.结果表明,叔丁醇钾和叔丁醇钠可高效催化聚(碳酸丁二醇酯)解聚,且表现出不同的产物选择性,叔丁醇钾催化解聚时主要生成十四元环二聚体(7CC)_(2),而叔丁醇钠催化解聚优先生成七元环碳酸酯单体7CC.理论计算结果表明,相比生成7CC,解聚生成(7CC)_(2)为优势反应路径;提高反应温度有利于提高7CC的选择性.当叔丁醇钾催化聚(碳酸戊二醇酯)以及聚(碳酸己二醇酯)解聚时,只能得到相应的十六/十八元环二聚体,而没有八/九元环碳酸酯单体生成.本研究有望为进一步发展脂肪族聚碳酸酯的高效解聚回收方法提供实验基础与理论依据.The catalytic depolymerization and recycling of aliphatic polycarbonates have attracted increasing attention in recent years.The crystalline structure of aliphatic polycarbonates impedes the penetration of solvents and catalysts,thereby reducing depolymerization activity.Additionally,the thermal depolymerization reaction process is complex,accompanied by numerous side reactions and a lack of high selectivity in recovering the target product.Consequently,the depolymerization behaviors and products of aliphatic polycarbonate are highly complex and influenced by numerous factors.In this study,we investigated the depolymerization reactions and behaviors of poly(butylene carbonate),poly(pentylene carbonate),and poly(hexylene carbonate)under various catalysts and reaction conditions using intrinsic melting methods.Furthermore,the differences in product selectivities were characterized through-NMR spectroscopy.The results demonstrated that potassium tert-butoxide and sodium tert-butoxide were found to be highly effective catalysts for the depolymerization of poly(butylene carbonate),with distinct product selectivities.Specifically,potassium tert-butoxide was observed to favor the depolymerization process,resulting in the production of primarily fourteen-membered cyclic dimer(7CC)_(2).In contrast,sodium tert-butoxide exhibited a preference for the generation of seven-membered cyclic carbonate monomers(7CC).Theoretical calculations indicated that the production of(7CC)_(2) was a more dominant reaction pathway than the generation of 7CC.Increasing the reaction temperature was found to improve the selectivity for 7CC production.Poly(pentylene glycol carbonate)and poly(hexylene glycol carbonate)were observed to produce only the corresponding sixteen-/eighteen-membered cyclic dimers,with no eight-/nine-membered cyclic monomers being produced.The objective of this research is to provide an experimental and theoretical basis for further development of efficient depolymerization and recycling methods for aliphatic polycarbonates

关 键 词：脂肪族聚碳酸酯 催化剂 解聚回收 环碳酸酯 

分 类 号：TQ323.41[化学工程—合成树脂塑料工业] TQ426