Relative reactivities of epoxide monomers during copolymerization with carbon dioxide

Abstract

The copolymerization of CO 2 /propylene oxide (PO)/cyclohexene oxide (CHO) was carried out using a Zn-based heterogeneous catalyst, namely a supported multi-component zinc dicarboxylate. The monomer reactivity ratios of PO ( r P O ) to CHO ( r C H O ) were estimated using the Fineman-Ross and Kelen-Tudos graphical methods. The results showed that the r P O values were significantly higher than the corresponding r C H O values in all cases, indicating that the incorporation of CHO into the polymer was kinetically unfavorable. The influence of the reaction temperature and pressure on the monomer reactivity ratios was also discussed. It was found that raising either the reaction temperature or pressure led to an increase in r C H O . In contrast, r P O decreased upon increasing the reaction temperature, but exhibited a small fluctuation upon increasing the reaction pressure. • Fineman-Ross and Kelen-Tudos methods were used to determine monomer reactivity ratios during the terpolymerization of CHO, PO and CO 2 with supported multi-component zinc dicarboxylate catalyst. • The r P O values were higher than 2, and the r C H O values were less than 0.5, meaning that a kinetic preference for incorporation of PO in the polymer. • The influence of the reaction temperature and pressure on the monomer reactivity was discussed.