Effect of imidazolium ionic liquids anions on copolymerization of CO2 with cyclohexene oxide by CrIII(Salen)Cl

The copolymerization of carbon dioxide and cyclohexene oxide was investigated without using solvent in the presence of ionic liquids based on 1-butyl-3-methylimidazolium with anions Cl- (BMI.Cl) and BF4(-) (BMI.BF4) were used as cocatalyst. The catalyst used was chloro (1R,2R)-(-)-[1,2-cyclohexanediamine-N,N'-bis(3,5-di-tert-butylsalicilidene)] chromium (III) [(Cr(Salen)Cl)]. Parameters like molar ratio catalyst/cocatalyst, pressure of CO2 and the nature of cocatalyst were evaluated. The imidazolium ionic liquids were effective as cocatalyst. The BMI.Cl provided better results than when used BMI.BF4. Poly(cyclohexene carbonate) PCHC with high carbonate units (98%) and lower polydispersity (1.4) was obtained under pressure of 30 bar of carbon dioxide and using 10 equivalents of BMI.Cl. (C) 2016 Elsevier B.V. All rights reserved.