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首页> 外文期刊>Catalysis Today >Effect of alpha-, beta-, gamma-, and delta-dicarbonyl complexing agents on the double metal cyanide-catalyzed ring-opening polymerization of propylene oxide
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Effect of alpha-, beta-, gamma-, and delta-dicarbonyl complexing agents on the double metal cyanide-catalyzed ring-opening polymerization of propylene oxide

机译：α，β-，γ-和δ-二羰基络合剂对环氧丙烷双金属氰化物催化开环聚合的影响

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摘要

Organic complexing agent (CA) plays a crucial role in generating active sites of double metal cyanide (DMC) catalyst in the ring-opening polymerization (ROP) of epoxides. Considering dicarbonyl compounds are versatile and present a great variety of coordination modes besides the usual bidentate behavior of monoanions, the usefulness of the dicarbonyl compounds as CAs for Zn(II)-Co(III) DMC catalysts is investigated. The structural properties of the catalysts were defined by X-ray powder diffraction patterns, elemental analysis, and thermogravimetric analysis. The interaction of the dicarbonyl ligand on the catalyst surface is evaluated by integrating infrared, UV-vis absorption and X-ray photoelectron spectroscopies. The turnover frequencies (calculated by mol-PO per mol-Zn per minute) of the DMC catalysts bearing beta-, gamma-, and delta-diesters are significantly higher than those of conventional catalysts specifically bearing tert-butyl alcohol as a CA. The resultant polyols exhibit very low levels of unsaturation and narrow polydispersity indexes. The molecular weight and functionality of the resultant polyols can be tuned by modifying the polymerization parameters. Systematic studies on the effect of the new CAs on the catalytic behavior offer great potential for the synthesis of high quality polyols.
机译：有机络合剂（CA）在环氧化合物开环聚合（ROP）中生成双金属氰化物（DMC）催化剂活性中心起着关键作用。考虑到二羰基化合物用途广泛，除了单阴离子通常的双齿行为外，还表现出多种配位模式，研究了二羰基化合物作为Zn（II）-Co（III）DMC催化剂的CAs的有用性。通过X射线粉末衍射图、元素分析和热重分析确定了催化剂的结构性质。结合红外光谱、紫外-可见吸收光谱和X射线光电子能谱对二羰基配体在催化剂表面的相互作用进行了评价。含有β-二酯、γ-二酯和δ-二酯的DMC催化剂的周转频率（以mol-PO/mol-Zn/min计算）显著高于含有叔丁醇作为CA的常规催化剂。合成的多元醇表现出非常低的不饱和度和狭窄的多分散指数。合成多元醇的分子量和功能性可以通过改变聚合参数来调节。系统研究新CAs对催化行为的影响，为合成高质量多元醇提供了巨大的潜力。

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