可循环丙烯酸酯类聚合物的高效可控合成  

Efficient and Controllable Synthesis of Recyclable Acrylate-based Polymers

作　　者：张振兴 吴小余 洪缪 Zhen-xing Zhang;Xiao-yuWu;Miao Hong(Department of Chemistry,School of Science,Shanghai University,Shanghai 200444;State Key Laboratory of Organometallic Chemistry,Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,Shanghai 200032)

机构地区：[1]上海大学理学院化学系,上海200444 [2]中国科学院上海有机化学研究所,金属有机化学国家重点实验室,上海200032

出　　处：《高分子学报》2022年第9期1150-1160,共11页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51973232,21821002);上海市科学技术委员会资助项目(项目号19QA1411100,22ZR1481900)。

摘　　要：通过锌介导的烯丙基化-内酯化反应,以乙醛和2-溴甲基丙烯酸乙酯为原料,在常温超声条件下一锅法实现γ-甲基-α-亚甲基-γ-丁内酯(γ-MMBL)的简单高效合成(5 min,Conv.>99.0%,Yield=80.0%),并成功地将该方法应用于枯茗醛、糠醛、月桂醛3种生物基醛衍生的新型亚甲基丁内酯类单体的高产率制备(Yield=80.4%~83.5%).在此基础上,探究不同的路易斯酸碱(Lewis pair,LP)催化剂结构对3种新单体的聚合行为影响,发现以双(2,6-二叔丁基-4-甲基苯酚)甲基铝(Me Al(BHT))或三(2,4,6-三氟苯基)硼(B(2,4,6-FCH))为路易斯酸(Lewis acid,LA),以1,3-二异丙基-4,5-二甲基咪唑-2-叶立德(I~iPr)为路易斯碱(Lewis base,LB),可实现其高活性的可控/活性聚合,制备得到结构多样、玻璃化转变温度大范围可调(T_(g)=92~223℃)的丙烯酸酯类聚合物.此外,利用马弗炉和冷阱联用的装置研究所得聚合物的热解聚行为,最终实现了3种新型聚亚甲基丁内酯的高效热解聚,高纯单体的回收率最高可达98.8%,建立起了聚合-解聚的闭环回收,拓展了可化学循环丙烯酸酯类聚合物的种类.Despite thatγ-methyl-α-methylene-γ-butyrolactone(γ-MMBL)shows great potential in substituting the methyl methacrylate(MMA)for synthesizing the acrylic polymer with intriguing physical properties and enhanced depolymerization selectivity,the possibly industrial production of this cyclic monomer is unfortunately not practical due to low overall yields,harsh reaction conditions,and time-consuming multistep process.Here we report a convenient and effective synthetic approach toγ-MMBL via zinc-mediated allylation-lactonization onepot reaction of acetaldehyde with ethyl 2-(bromomethyl)acrylate.Under simple room-temperature sonication conditions,quantitative conversions can be accomplished within 5 min,providing pureγ-MMBL with high isolated yields of 80%.This synthetic method can also be applied to efficient preparation of cuminaldehyde,2-furaldehyde,lauraldehyde-derived methylene butyrolactones with high yields(80.4%?83.5%).The development of Lewis pair catalyst based on methylaluminum bis(2,6-di-tert-butyl-4-methylphenoxide)(Me Al(BHT))or tris(2,4,6-trifluorophenyl)borane(B(2,4,6-FCH))Lewis acid and 3-diisopropyl-4,5-dimethylimidazol-2-ylidene(IPr)Lewis base enables their rapid polymerizations with a high degree of control,affording new poly(methylene butyrolactone)s with thermal properties tuned in a wide range.Through the utilization of a muffle furnace coupled with a cooling-trap,effective depolymerizations of these poly(methylene butyrolactone)s have been achieved with monomer recovery up to 98.8%,thus successfully constructing new acrylic polymers with closed-loop recyclability.

关 键 词：可循环高分子 丙烯酸酯类聚合物 可控/活性聚合 路易斯酸碱聚合 亚甲基丁内酯 

分 类 号：TQ317[化学工程—高聚物工业]