Studies On Influencing Factors Of Polyketone Molecular Weight By Palladium Catalyzed Alternating Copolymerization With Carbon Monoxide And Ethylene

摘要

With Pd(AcO)_2DPPP as catalytic precursor of CO/C_2H_4 alternating copolymerization. The main factors which affect the molecular weight of polyketone were studied. The results showed that: Temperature was the most important factor in copolymerization. The polyketone molecular weight lower faster with increasing temperature, have a decrease of 53% when system temperature rise from 70°C to 80°C, and the palladium-catalyzed progenitor easy to decomposition and become deactivation. Adding pressure was in favor of the increase of copolymerization rate and molecular weight. Water content in methanol solvent was sensitive to copolymerization rate, as far as molecular weight was concerned, it made no difference. HClO_4 and other strong acids in the catalytic system will help improve the molecular weight of the polyketone.