Syndiotactically enriched 1,2-selective polymerization of 1,3-butadiene initiated by iron catalysts based on a new class of donors
Syndiotactically enriched 1,2-selective polymerization of 1,3-butadiene initiated by iron catalysts based on a new class of donors
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DOI：
10.1016/j.polymer.2009.10.060
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发表时间：
2009-11-27
期刊：
影响因子：
4.6
通讯作者：
Jiang, Liansheng
中科院分区：
文献类型：
--
作者：
Gong, Dirong;Dong, Weimin;Jiang, Liansheng
合成了一系列含磷酰基（P=O）的化合物：磷酸三乙酯（a）、磷酸二乙苯酯（B）、磷酸二苯乙酯（c）、磷酸三芳基酯（d和h-m）、三苯基氧化膦（e）、二苯基次膦酸苯酯（f）和苯基膦酸二苯酯（g）。在50 ℃下测试通过将化合物与Fe（2-EHA）（3）和（AlBu 3）-Bu 1在己烷中混合而原位产生的铁催化剂用于丁二烯聚合。磷酸盐供体催化剂已被前所未有地发现进行丁二烯的极高间同立构（五单元组，rrrr=46.1-94.5%）富集的1，2-选择性（1，2-结构含量=56.2-94.3%）聚合。在磷酸三苯酯（k-m）苯环上引入吸电子取代基显著提高了催化活性，而在2位（h）引入大体积异丙基取代基对区域选择性有有利影响。就业的e，为g作为供体，在抑制单体转化率，伴随着恶化的1，2-区域选择性的结果。以三（2，4-二氟苯基）磷酸酯（m）为给体，考察了反应温度、助催化剂种类、聚合介质等聚合条件对聚合的影响。首次在铁基催化剂中观察到对高达80 ℃的聚合温度的高度耐受性。(C)2009爱思唯尔有限公司保留所有权利。
A series of phosphoryl (P=O) contained compounds: triethylphosphate (a), diethyl phenyl phosphate (b), ethyldiphenylphosphate (c) triarylphosphates (d and h-m), triphenylphosphine oxide (e), phenyl diphenylphosphinate (f) and diphenyl phenylphosphonate (g) have been prepared. Iron catalysts, which are generated in situ by mixing the compounds with Fe(2-EHA)(3) and (AlBu3)-Bu-i in hexane, are tested for butadiene polymerization at 50 degrees C. Phosphates donated catalysts have been, unprecedently, found to conduct extremely high syndiotactically (pentad, rrrr=46.1-94.5%) enriched 1,2-selective (1,2-structure content=56.2-94.3%) polymerization of butadiene. Introduction of electron withdrawing substituents on phenyl rings of triphenylphosphate (k-m) remarkably promotes catalytic activity, while bulky substituent isopropyl at 2-position (h) has beneficial influence on regioselectivity. Employment of e, for g as donor, results in a suppressed monomer conversion, accompanied by deteriorated 1,2-regioselectivity. The effects of polymerization conditions such as reaction temperature, types of cocatalysts and polymerization medium are also investigated by using catalyst system with tri(2,4-difluorophenyl)phosphate (m) as donor. Highly tolerance to polymerization temperature up to 80 degrees C is observed for the first time in the iron-based catalyst. (C) 2009 Elsevier Ltd. All rights reserved.