Polymerization of methyl methacrylate using bis(β‐ketoamino)nickel(II)–MAO catalytic systems

Abstract

The polymerization of methyl methacrylate (MMA) was investigated using a series of bis(β-ketoamino)nickel(II) complexes in combination with methylaluminoxane in toluene solution. The binary catalyst is necessary for initiating MMA polymerization and producing PMMA with high molecular weights but broad molecular weight distributions. The effects of reaction temperature and Al : Ni molar ratios on the polymerization of MMA were examined in detail. Both steric bulk and electronic effects of the substituents around the imino group in the ligand on MMA polymerization activities could be observed. Relative to electronic effects, the steric hindrance of the ligands displayed a more significant effect on the catalytic activities, with the catalytic activity sequence observed in the order 4 > 1 > 2 > 3 > 5 > 6. Structural analyses of the polymers by 13 C NMR spectra indicate that polymerization yields PMMA with a syndiotactic-rich atactic microstructure.

Nickel(II) complexes bearing the bis(β‐ketoamino) ligand for the copolymerization of norbornene with a higher 1‐alkene

“…As depicted in Figure 1, the crystal structures of the complex Ni{CF 3 C(O)CHC[N(naphthyl)]CH 3 } 2 were similar to those of the analogue complexes we previously reported, 21,22 and all shared the fourcoordination binding mode around a nickel(II) center.…”

Nanostructured functional co-polymers bioconjugate integrin inhibitors

“…The CAN stretching mode in P(MMA-co-DMPA) has been observed at about 1180 cm À1 and the S-H stretching of P(MMA-co-AM) samples at about 2560 cm À1 . NMR spectra confirmed the formation of the co-polymers, and the resonance of aliphatic protons allowed to assess the random atactic linkage between monomers [36]. GPC traces allowed to determine the molecular weights of the samples, in the range 5 Â 10 4 -5 Â 10 3 a.m.u., depending on the different effects of monomers with different polarity.…”

Synthesis, Characterization and Biological Activity of Polymer Nickel (Ii) Complex

“…Nickel (II) complexes bearing N, O-chelate ligand activation for MMA polymerization yielded poly (methyl methacrylate) (PMMA) with rich syndiotacticity microstructure [4][5][6][7][8][9][10]. The chelating polymers find applications in bioinorganic industry [11], wastewater treatment [12,13], pollution control [14], hydrometallurgy [15], preconcentration [16], anionic polyelectrolyte hydrogels [17], cation-exchange resins [18] , showed potential applications in material science as conductive [19], luminescent [20], magnetic, porous, chiral or non-linear optical materials [21], catalytic [22][23][24][25],organic synthesis [26], polymer drug graft, recovery of trace metal ions [13] and antimicrobial activities [27,28].…”