Dioxomolybdenum(VI) and Dioxotungsten(VI) Complexes: Efficient Catalytic Activity for Crosslinking Reaction in Ethylene-Vinyl Acetate Copolymer / Alkoxysilane Composites
Dioxomolybdenum(VI) and Dioxotungsten(VI) Complexes: Efficient Catalytic Activity for Crosslinking Reaction in Ethylene-Vinyl Acetate Copolymer / Alkoxysilane Composites
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二氧钼 (VI) 和二氧钨 (VI) 配合物：乙烯-醋酸乙烯酯共聚物/烷氧基硅烷复合材料中交联反应的高效催化活性
DOI：
10.1002/pat.3491
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
T. Hirano
中科院分区：
文献类型：
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作者：
K. Adachi;S. Toyomura;Y. Miyakuni;S. Yamazaki;K. Honda;T. Hirano
几种双金属催化剂的催化性能研究了乙酰丙酮基金属配合物[Cu（acac）2、Zn（acac）2、TiO（acac）2、VO（acac）2、MoO 2（acac）2和WO 2（acac）2]在乙烯-乙酸乙烯酯共聚物/正硅酸乙酯体系中的交联反应（伊娃/TEOS）复合体系通过动态衰减全反射傅里叶变换红外光谱、溶剂溶胀、和固态29 Si交叉极化/魔角自旋核磁共振技术。动力学研究结果表明，MoO 2（acac）2和WO 2（acac）2的催化活性高于二正丁基氧化锡（IV），后者是聚合物体系中酯交换反应最常用的催化剂，但对环境健康有毒性作用。交联伊娃/TEOS复合材料的交联密度和最终硅氧烷网络结构与所用催化剂密切相关。基于SN 2-Si反应途径，提出了MoO 2（acac）2和WO 2（acac）2催化伊娃主链上的乙酸乙烯酯与TEOS分子中的乙氧基硅烷发生交换反应的可能机理.本研究的结果有望填补高分子体系交联反应领域高性能、环境友好催化剂的空白，并为其它交联反应提供有益的线索。版权所有© 2015约翰威利父子有限公司.
The catalytic performances of several bis(acetylacetonato)metal complexes [Cu(acac)2, Zn(acac)2, TiO(acac)2, VO(acac)2, MoO2(acac)2, and WO2(acac)2] were investigated for the crosslinking reaction via transesterifications in the ethylene‐vinyl acetate copolymer/tetraethoxysilane (EVA/TEOS) composite system by means of dynamic attenuated total reflectance Fourier transform infrared, solvent swelling, and solid‐state29Si cross polarization/magic angle spinning nuclear magnetic resonance techniques. Results of the kinetic examination revealed that MoO2(acac)2and WO2(acac)2exhibited a higher catalytic activity than di‐n‐butyltin(IV) oxide, which is a catalyst most commonly used for the transesterification process in polymer system, but has a toxic effect on the environmental health. And furthermore, the crosslink density and final siloxane network structure of crosslinked EVA/TEOS composites are found to be greatly correlated with the catalyst used. On the basis of the SN2‐Si pathway, a plausible catalytic mechanism of MoO2(acac)2and WO2(acac)2was proposed for the crosslinking reaction via transesterifications of the vinyl acetate moieties in EVA backbone with the ethoxysilane groups in one TEOS molecule. The findings in this study may fill the blank in the high performance and environmentally friendly catalyst in the field of the crosslinking reactions in polymer system and provide useful clue for other transesterifications. Copyright © 2015 John Wiley & Sons, Ltd.