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

✍ Scribed by Xiaohui He; Qing Wu

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 296 KB
• Volume: 20
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/aoc.1045

✦ Synopsis

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. Copyright © 2006 John Wiley & Sons, Ltd.