Addition polymerization of norbornene using Bis(beta-ketoamino)nickel(II)/Tris(pentafluorophenyl) borane catalytic systems

作者：He, Xiaohui; Chen, Yiwang^*; Liu, Yongming; Yu, Shuman; Hong, Sanguo; Wu, Qing

来源：Journal of Polymer Science Part A: Polymer Chemistry , 2007, 45(20): 4733-4743.

DOI：10.1002/pola.22221

• catalytic polymerization
• late transition metal
• metal-organic catalysts/organometallic
• catalysts
• microstructure
• norbornene
• polyolefins
• transition metal
• chemistry
• vinyl-addition polymerization

Norbornene polymerizations proceeded in toluene with bis(f-ketoamino)nickel(II) (Ni[CH3C(O)CHC(NR)CH3](2) [R = phenyl (1) or naphthyl (2)]} complexes as the catalyst precursors and the organo-Lewis compound tris(pentafluorophenyl)borane [B(C6F5)(3)] as a unique cocatalyst. The polymerization conditions, such as the cocatalyst/catalyst ratio (B/Ni), catalyst concentration, monomer/catalyst ratio (norbornene/Ni), polymerization temperature, and polymerization time, were studied in detail. Both bis(/l-ketoamino)nickel(II)/B(C6F5)(3) catalytic systems showed noticeably high conversions and activities. The polymerization activities were up to 3.64 x 10(7) g of polymer/mol of Ni h for complex 1/(B(C6F5)(3) and 3.80 x 10(7) g of polymer/mol of Ni h for complex 2/B(C6F5)(3), and very high conversions of 90-95% were maintained; both polymerizations provided high-molecular-weight polynorbornenes with molecular weight distributions (weight-average molecular weight/number-average molecular weight) of 2.5-3.0. The achieved polynorbornenes were confirmed to be vinyl-addition and atactic polymers through the analysis of Fourier transform infrared, H-1 NMR, and C-13 NMR spectra, and the thermogravimetric analysis results showed that the polynorbornenes exhibited good thermal stability (decomposition temperature > 410 degrees C).

• 出版日期2007-10-15
• 单位中山大学; 南昌大学