Solvent-free ring-opening polymerization of cyclohexene oxide catalyzed by palladium chloride

In this study, we have for the first time demonstrated that palladium chloride (PdCl2) is an efficient catalyst for ring-opening polymerization of cyclohexene oxide in a solvent-free condition. The polymerization product was in atactic structure, and reaction conditions, such as reaction temperature, time, and catalyst amount, showed effects on polymerization conversion yield, turnover number, and number-average molecular weight of the resulting poly(cyclohexene oxide). PdCl2 catalysis follows a cationic ring-opening mechanism. The polymerization result is highly determined by the chemical structure of the monomers.