ALTERNATING COPOLYMERIZATION OF CYCLOHEXENE OXIDE AND CARBON DIOXIDE UNDER COBALT PORPHYRIN CATALYST

Cobalt porphyrin complexes ((TPPCoX)-X-III) (TPP = 5,10,15,20-tetraphenyl-porphyrin; X = halide) in combination with bis(triphenylphosphine) iminium chloride (PPNCl) were used for the copolymerization of cyclohexene oxide and CO2. The highest turnover frequency of 67.2 h(-1) was achieved after 13 h at 20 degrees C, and the obtained poly(1,2-cyclohexylene carbonate) (PCHC) showed number average molecular weight (M-n) of 10 x 10(3). Though the obtained PCHC showed atactic structure, the m-centered tetrads content reached 58.1% at CO2 pressure of 1.0 MPa, and decreased to 51.9% at CO2 pressure of 6.0 MPa, indicating that it was inclined to form atactic polymer at high CO2 pressure.