锌-钴氰化络合物催化剂的改性及其在聚醚碳酸酯二元醇合成中的应用

Modification of Zn-Co DMC catalyst and its application in the synthesis of poly(ether-carbonate) polyols

双金属氰化物(double mental cyanide,DMC)是一种用于二氧化碳与环氧丙烷(PO)共聚反应的催化剂。DMC催化剂是具有晶体结构的有机金属配合物,其催化活性与结晶度密切相关。加入配体、共配体能够破坏立方晶体结构、增加无定形态结构从而降低结晶度。研究证明,以叔丁醇为配体的DMC催化剂活性较高,但是对共配体的使用则鲜有报道。本研究使用不同共配体(Span80、Tween80、D400、D2000)对DMC催化剂改性以达到两个目的:一是降低结晶度,提高催化剂活性;二是减小催化剂粒径。此外,利用PO与CO_(2)的共聚反应对催化剂性能进行考察。结果表明,使用D2000作为共配体改性后的DMC+D2000催化剂,催化活性为1547 g/g_(cat),聚合产物中碳酸酯单元占聚合部分的质量分数为25.3%,选择性为92.1%。

Double mental cyanide(DMC)is a catalyst for the ring-opening copolymerization of carbon dioxide and propylene oxide.DMC catalysts are organometallic complexes with crystal structure,and their catalytic activity is closely related to crystallinity.The addition of ligand and co-ligand can destroy the cubic crystal structure,increase the amorphous structure and reduce the crystallinity.A number of studies have proved that tert-butanol as the ligand DMC catalyst has high activity,but there are few reports on the use of co-ligand.In this paper,DMC catalyst was modified with different co-complexing agents(Span80,Tween80,D400,D2000),which decrease crystallinity,catalyst particle size and eventually increase catalyst activity.The properties of the catalyst were investigated by copolymerization of PO with CO_(2).The results showed that the catalytic activity of DMC+D2000 modified with D2000 as co-ligand was 1547 g/g_(cat).The molar fraction of carbonate unit in the polymerization product was 25.3%,and the selectivity was 92.1%.