HOMOPOLYMERIZATION OF PROPYLENE-OXIDE AND CO-POLYMERIZATION OF PROPYLENE-OXIDE AND CARBON-DIOXIDE WITH METAL-SALTS OF ACETIC-ACID

In the reported experiments, the homopolymerization of propylene oxide was first conducted at 80 degree C in the absence of any solvent by using various metal salts of acetic acid and it was found that Mg(OAc)//2, Cr(OAc)//3, Mn(OAc)//2, Co(OAc)//2, Ni(OAc)//2, Zn(OAc)//2, and Sn(OAC)//2 were effective for the polymerization. The copolymerization of propylene oxide and carbon dioxide was next examined by using these effective metal salts of acetic acid as catalysts. Most of these were effective also for the copolymerization. The nature of the polymer obtained was strongly dependent on the catalyst used. Co(OAc)//2 and Zn(OAc)//2 gave an alternate copolymer of propylene oxide and carbon dioxide, Mg(OAc)//2, Cr(OAc)//3, and Ni(OAc)//2 gave a random copolymer, while Sn(OAc)//2 gave a homopolymer of propylene oxide. Then the copolymerization of propylene oxide and carbon dioxide was kinetically investigated in some detail by using Co(OAc)//2 as a catalyst. On the basis of the results obtained, a plausible mechanism was proposed for both the homopolymerization of propylene oxide and copolymerization of propylene oxide and carbon dioxide.