Synthesis of Biobased Polycarbonate by Copolymerization of Menth-2-ene Oxide and CO2 with Exceptional Thermal Stability

There is an urgent need for biobased raw materials, which are not food relevant and could serve as the base for novel sustainable polymers. Menthol is such a potential material, which is available in plenty from nature and also technically. We report here a challenging copolymerization of menth-2-ene oxide derived from menthol and CO2 in the presence of a beta-diiminate zinc complex which resulted in high molecular weight poly(menth-2-ene carbonate) (PMen2C). PMen2C shows a high glass transition temperature in combination with exceptional thermal stability, which is unusual for aliphatic polycarbonates and of utmost importance for melt processing. With a high thermal stability, PMen2C could be developed to a sustainable engineering polymer material.