Silica-supported zinc glutarate catalyst synthesized by rheological phase reaction used in the copolymerization of carbon dioxide and propylene oxide

In order to improve the catalytic efficiency of zinc glutarate (ZnGA) used in the CO 2 /propylene oxide (PO) copolymerization, silica-supported zinc glutarate catalysts (ZnGA/SiO 2 ) are prepared via a rheological phase reaction with a little toluene as a reaction medium. Wide-angle X-ray diffraction (WAXD) tests of the catalysts illustrate that the crystal quality increases and the overall crystallinity declines after supporting. The scanning electron microscope (SEM) images show that the proportion of supported ZnGA increases with increasing the SiO 2 proportion. Accordingly, the polymer yields increase from 12.7 Kg polymer/mol Zn of ZnGA to 25.6 of ZnGA/SiO 2 . And the almost alternating poly(propylene carbonasstes) (PPCs) with the carbonate content of above 97 % and the M n s of above 10, 000 g/mol are obtained. This work illustrates that the catalytic efficiency does not increase sharply like the supported catalysts used in olefin polymerization because of the decline in overall crystallinity of ZnGA. The catalytic efficiency is expected to be enhanced significantly if it can be improved for ZnGA/SiO 2 .