Vinylic polymerization of norbornene by Pd(II)-catalysis in the presence of ethylene

✍ Scribed by T. F. A. Haselwander; W. Heitz; M. Maskos

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 481 KB
• Volume: 18
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.1997.030180810

✦ Synopsis

Abstract

Pd(II) catalysts with nitrilo ligands and BF~4~^−^ counter ions give the best results in vinylic polymerization of norbornene. Absolute molecular weight determination of polynorbornene (PN) by means of light scattering and the three‐dimensional shape of PN were also investigated. By correlation of molecular weights M̄~w~ with intrinsic viscosity (Staudinger‐index) [η], yield a close to 0.5 exponent for the Mark‐Houwink equation with solvents chlorobenzene and cyclohexane at 25°C expected for polymer molecules with confined conformation. The vinylic polymerization of norbornene with [(CH~3~CN)~4~Pd][BF~4~]~2~ (I) in nitromethane in the presence of ethylene results in PN with narrow molecular weight distribution. No termination and transfer reactions were found, nor any incorporation of ethylene could be detected.