Alternating copolymerization of epoxides with carbon dioxide or cyclic anhydrides using bimetallic nickel and cobalt catalysts: Preparation of hydrophilic nanofibers from functionalized polyesters
Alternating copolymerization of epoxides with carbon dioxide or cyclic anhydrides using bimetallic nickel and cobalt catalysts: Preparation of hydrophilic nanofibers from functionalized polyesters
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DOI：
10.1016/j.polymer.2018.02.063
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发表时间：
2018-04-11
期刊：
影响因子：
4.6
通讯作者：
Ko, Bao-Tsan
中科院分区：
文献类型：
--
作者：
Chang, Chi-Hang;Tsai, Chen-Yen;Ko, Bao-Tsan
合成了一系列由含氮杂环salen型配体掺入的双核金属乙酸盐配合物1-6，进行了结构表征并作为催化剂制备可生物降解的聚碳酸酯和聚酯。系统地研究了它们对二氧化碳-环氧化物或环酸酐-环氧化物共聚的催化性能。双金属镍(II)配合物1、2和5是环己烯氧化物(CHO)与CO2交替共聚的活性催化剂；二镍配合物 1 被证明是最有效和选择性最高的，从而获得其中效率最高的聚（环己烯碳酸酯）。此外，配合物1还被发现可用于CO2与不同环状环氧化物的开环共聚，生成相应的聚碳酸酯。此外，二钴(II)类似物3、4和6是温和条件下CHO和邻苯二甲酸酐(PA)交替共聚的有效催化剂。根据催化研究的结果，配合物3被证明是最活跃的一种CHO-PA共聚反应，以“受控”方式生产聚合产物，涉及可控的分子量和窄的多分散性。有趣的是，Co配合物3还能够催化PA与4-乙烯基-1,2-环己烯氧化物共聚，获得侧链上带有乙烯基官能团的缔合聚酯，该聚酯通过硫醇-烯点击官能化进一步用叔胺部分官能化，并通过静电纺丝转化为纳米纤维。由于极性基团的引入，所得到的叔胺改性聚酯纳米纤维相对于未改性的对应物表现出改善的亲水性能，被认为具有作为新型功能性纤维材料的巨大潜力。 (C) 2018 Elsevier Ltd. 保留所有权利。
A series of di-nuclear metal acetate complexes 1-6 incorporated by nitrogen heterocycle-containing salen-type ligands have been synthesized, structurally characterized and performed as catalysts to prepare biodegradable polycarbonates and polyesters. Their catalytic performances for copolymerization of carbon dioxide-epoxides or cyclic anhydride-epoxides were systematically examined. Bimetallic nickel(II) complexes 1, 2 and 5 were active catalysts for the alternating copolymerization of cyclohexene oxide (CHO) with CO2; di-nickel complex 1 was shown to be the most effective and selective, leading to obtaining poly(cyclohexene carbonate) s with the best efficiency among them. Moreover, complex 1 was also found to be versatile for the ring-opening copolymerization of CO2 with different cyclic epoxides to give the corresponding polycarbonates. Additionally, di-cobalt(II) analogs 3, 4 and 6 were efficient catalysts for the alternating copolymerization of CHO and phthalic anhydride (PA) under mild conditions. Based on the results of catalytic studies, complex 3 was demonstrated to be the most active one CHO-PA copolymerization, producing the polymeric products with a "controlled" manner involving controllable molecular weights and narrow polydispersity. Interestingly, Co complex 3 was also able to catalyze the copolymerization of PA with 4-vinyl-1,2-cyclohexene oxide to obtain the associated polyester with the vinyl functionality on the side chains, which was further functionalized with tertiary amine moieties via thiol-ene click functionalization and converted to nanofibers through electrospinning. Due to the incorporation of polar groups, the resulting tertiary amine-modified polyester nanofibers that exhibit an improved hydrophilic property relative to their un-modified counterpart have been considered to have high potential to be utilized as a new functional fiber material. (C) 2018 Elsevier Ltd. All rights reserved.