Synthesis of CO2-based functional poly(carbonate-co-lactide)

TPPAlCl-PPN+Cl- binary catalyst (where TPPAlCl is 5,10,15,20-tetraphenylporphyrin aluminum chloride, PPN+Cl- is bis[triphenylphosphine] iminium chloride, the molar ratio of TPPAlCl to PPN+Cl- is 1 to 0.5) can initiate the effective one-pot/one-step ternary copolymerization of CO2, lactide and 4-vinyl-1-cyclohexene-1,2-epoxide, and the quaternary copolymerization of CO2, propylene oxide, lactide, 4-vinyl-1-cyclohexene-1,2-epoxide, to form multiblock poly(carbonate-co-lactide) products with pendant vinyl group. The ternary copolymerization product composes of polylactide (PLA) block and poy(vinylcyclohexylene carbonate) (PVCHC) block, and the quaternary copolymerization product composes of poy(propylene carbonate) (PPC) block, PLA block and PVCHC block, which are verified by H-1 NMR, C-13 NMR, H-1-H-1 cosy, hetero-nuclear multiple bond correlation, DTG, and Gel permeation chromatography analysis. The functionality and glass-transition temperature of the products can be easily adjusted by the copolymerization variables, such as the molar ratio of comonomers, copolymerization temperature, pressure of CO2, the concentration of the catalyst.