Synthesis and Rheological Properties of Poly(5-n-hexylnorbornene)

✍ Scribed by Kerstin Müller; Stefan Kreiling; Kurt Dehnicke; Jürgen Allgaier; Dieter Richter; Lewis J. Fetters; Youngsuk Jung; Do Y. Yoon; Andreas Greiner

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 130 KB
• Volume: 207
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200500228

✦ Synopsis

Abstract

Summary: Poly(5‐n‐hexylnorbornene) (PHNB) was obtained in high molecular weight and high yields by vinyl‐type polymerization of 5‐n‐hexyl‐2‐norbornene (endo/exo = 77/23) with [NiBr(NPMe~3~)]~4~/B(C~6~F~5~)~3~ as catalyst precursor. The combination of size exclusion chromatography with on‐line light scattering and intrinsic viscosity measurements allowed the Mark‐Houwink expressions to be evaluated in tetrahydrofuran. The unperturbed chain dimensions for poly(5‐n‐hexylnorbornene) were estimated via the extrapolation procedure of Burchard‐Stockmayer‐Fixman. This evaluation of the unperturbed chain dimension in turn permits the calculation of the entanglement molecular weight and the plateau modulus via the packing length model. This allows the determination of rheological properties for these materials where conventional rheology measurements are difficult, or impossible.

[η]‐M data for PHNB in THF at 35 °C.

magnified image[η]‐M data for PHNB in THF at 35 °C.