COORDINATION COPOLYMERIZATION OF STYRENE WITH MALEIC ANHYDRIDE BY RARE-EARTH COORDINATION CATALYSTS

<正> The study on coordination copolymerization of styrene （S） with maleic anhydride （MA） by rare-earth coordination catalysts, NdL3-Al（i-Bu）3, has been successfully carried out for the first time. Some features, kinetic behavior, and mechanism of the SMA copolymerization by Nd（naph）3-Al（i-Bu）3 system are described and discussed. The copolymex of styrenemaleic anhydride prepared by the NdL3-Al（i-Bu）3 systems in benzene at 50℃ is an alternating-rich white powder having high number-average molecular weight of 6—8.5×10～5. The overall activation energy for the polymerization was found to be 10.5KJ/mol. The polymerization was not suppressed by addition of hydroquinone. The catalytic activity of various ligands in NdL3 for the copolymerization decreases in the following order: Nd （naph）3>Nd-(P507)3～NdCl3-6H2O>Nd(P204)3>Nd（acac）3. 3H2O. The experimental results are explained based on a mechanism to be the coordination-type copolymerization in terms of the participation of a monomer-monomer c