Application of thiol-ene click chemistry to preparation of functional polyethylene with high molecular weight and high polar group content: Influence of thiol structure and vinyl type on reactivity
Application of thiol-ene click chemistry to preparation of functional polyethylene with high molecular weight and high polar group content: Influence of thiol structure and vinyl type on reactivity
复制标题
硫醇-烯点击化学在制备高分子量、高极性基团含量功能聚乙烯中的应用：硫醇结构和乙烯基类型对反应活性的影响
DOI：
10.1002/pola.26026
复制
发表时间：
2012-06-15
影响因子：
--
通讯作者：
Li, Yue-Sheng
中科院分区：
文献类型：
--
作者：
Hong, Miao;Liu, San-Rong;Li, Yue-Sheng
以[PhNC(CF3)CHCO(Ph)]2TiCl2为催化剂，通过区域选择性乙烯/5-乙烯基-2-降冰片烯（VNB）共聚，在紫外光引发的巯基点击反应下，简单高效地合成了一系列功能化聚乙烯。用巯基乙醇、1-巯基甘油、巯基乙酸甲酯、巯基丙酸甲酯、2-巯基乙胺、巯基乙酸和巯基丙酸等不同的硫醇处理乙烯/VNB共聚物，成功地在聚乙烯中引入了不同的极性基团。除2-巯基乙胺外，其余化合物的功能化效率均高于94%，且与硫醇结构和双键含量无关。功能聚乙烯中极性基团的含量可以在0.030 mol %的范围内调节。凝胶渗透色谱图谱表明，所有功能聚乙烯都具有非常高的分子量（160336 kg/mol）和均匀的形成。此外，还系统地研究了乙烯基类型和硫醇结构对反应性的影响。通过用不同共聚物（乙烯/VNB、乙烯/5-乙基-2-降冰片烯、乙烯/双环戊二烯共聚物）处理巯基乙醇，乙烯基反应性的顺序可归纳为末端>内>环双键。对于不同的硫醇，其反应活性顺序为：SHCH2COOH > SHCH2COOCH3 > SHCH2CH2COOH > SHCH2CH2COOCH3 > SHCH2CH(OH)CH2OH > SHCH2CH2OH > SHCH2CH2NH2，主要取决于其溶解度和极性基团的吸电子感应效应。(c) 2012 Wiley期刊有限公司高分子材料学报，2012
A series of functional polyethylenes have been simply and efficiently synthesized via the combination of regioselective ethylene/5-vinyl-2-norbornene (VNB) copolymerization using [PhNC(CF3)CHCO(Ph)]2TiCl2 catalyst and following ultraviolet light initiated thiol-ene click reaction. On treatment of ethylene/VNB copolymer with different thiols including mercaptoethanol, 1-thioglycerol, methyl mercaptoacetate, methyl mercaptopropionate, 2-mercaptoethylamine, mercaptoacetic acid, and mercaptopropanoic acid, various polar groups have been successfully introduced into the polyethylene. Except 2-mercaptoethylamine, the functionalizations are quite efficient with the degree of functionalization higher than 94%, which is independent of thiol structure and double bond content. The content of polar group in functional polyethylene can be tuned in a wide range of 030 mol %. Gel permeation chromatography profiles indicate all functional polyethylenes that have very high molecular weights (160336 kg/mol) with homogeneous formation. Besides, systematic investigation of the influence of vinyl type and thiol structure on reactivity has been also carried out. By treatment of mercaptoethanol with different copolymers (ethylene/VNB, ethylene/5-ethylidene-2-norbornene, and ethylene/dicyclopentadiene copolymer), the order of vinyl reactivity can be summarized as terminal > internal > cyclic double bond. For different thiols, the reactivity has the sequence of SHCH2COOH > SHCH2COOCH3 > SHCH2CH2COOH > SHCH2CH2COOCH3 > SHCH2CH(OH)CH2OH > SHCH2CH2OH > SHCH2CH2NH2, which is depended on the solubility and the electron-withdrawing inductive effect of polar group. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012