Copolymerization of ethylene with methyl methacrylate by Ziegler-Natta-type catalysts based on nickel salicylaldiminate/methylalumoxane systems

Full Paper: Bis(silicylaldiminate)nickel(II) complexes, such as bis[N(2,6-diisopropylphenyl) salicylaldiminate]-nickel(II) and gis(N-isopropylsalicylaldiminate)nickel(II), were activated by methylalumoxane (MAO) to give catalytic systems able to copolymerize ethylene (E) with methyl methacrylate (MMA), thus producin low molecular weight copolymers with a rather high content of MMA co-units (50-80 mol-%). On the contrary, when catalytic systems, obtained by oxidative addition of salicylaldimine ligands such as 5-nitro-N-(2,6-diisopropylphenyl)salicylaldimine (DNPS) to bis(cyclooctadienyl)nickel(0) [Ni(cod)(2)], were activated with MAO, high viscometric average molecular weight ((M) over bar (v) 10-30 x 10(4) Da) E/MMA copolymers with a low content of MMA co-units (3-6 mol-%) were formed, thus allowing to obtain directly by synthesis functionalized highly linear poly(ethylene)s (T-m up to 130degreesC) to be potentially applied as new materials with improved surface properties.