Vinyl-addition copolymerization of norbornene and polar norbornene derivatives using novel bis(β-ketoamino)Ni(II)/B(C6F5)3/AlEt3 catalytic systems

Abstract

Copolymerization of norbornene (NBE) and polar norbornene derivatives undergoes vinyl polymerization by using novel catalyst systems formed in situ by combining bis(β-ketoamino)Ni(II) complexes {Ni[R1C(O)CHC(NR3)R2]2 (Rl = R2 = CH3, R3 = naphthyl, 1; R1 = R2 = CH3, R3 = C6H5, 2; R1 = C6H5, R2 = CH3, R3 = naphthyl, 3; Rl = R2 = CH3, R3 = 2, 6-(CH3)2C6H3, 4; R1 = R2 = CH3, R3 = 2, 6-′Pr2C6H3 5; R1 = C6H5, R2 = CH3, R3 = 2, 6-′Pr2C6H3, 6)} and B(C6F5)3/AlEt3 in toluene. The 1/B(C6F5)3/AlEt3 catalytic system is effective for copolymerization of NBE with NBEOCOCH3 and NBECH2OH, respectively, and copolymerization activity is followed in the order of NBECH2OH > NBEOCOCH3 > NBECN. The molecular weights of the obtained poly(NBE/NBECH2OH) reached 5.97 × 104 to 2.07 × 105 g/mol and the NBECH2OH incorporation ratios reached 7.0–55.4 mol % by adjusting the comonomer feedstock composition. The copolymerization of NBE and NBE CH2OH also depend on catalyst structures and activity of catalyst followed in the order of 2 > 1 > 3 > 5 > 4 > 6. The molecular weights and NBECH2OH incorporation ratios of poly(NBE/NBECH2OH) were adjustable to be 1.91–5.37 × 105 g/mol and 9.5–41.1 mol % OH units by using catalysts 1–6. The achieved copolymers were confirmed to be vinyl-addition type, noncrystalline and have good thermal stability (Td = 380–410°C). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011