Bis(β-ketoimino)nickel(Ⅱ) Complexes Designed for Random Vinyl-Addition Copolymerization of Norbornene and Methyl 5-Norbornene-2-carboxylate
발표자
()
초록
내용
Containing the polar group in cyclic olefin copolymers (COCs) has been conducted for strategy to overcome the conventional drawbacks of COCs. Although many efforts have been proceeded for using the nickel(Ⅱ) and palladium(Ⅱ) complexes catalyzed the copolymerization with polar monomers, random copolymerization has been limited due to the monomer selectivity caused by the steric hindrance. We designed a several bis(β-ketoimino)nickel(Ⅱ) complexes with the least steric hindrance to minimize the monomer selectivity for random vinyl-addition copolymerization of norbornene and methyl 5-norbornene-2-carboxylate. The incorporation of ester group was precisely controlled by the feed ratio of monomers and the copolymers showed the polymer properties tunable by controlling the ester group contents. In this work, we offer the design principle of the catalyst to prepare a random COCs with predictable composition and homogeneous ester group distribution