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Polímeros

versão impressa ISSN 0104-1428versão On-line ISSN 1678-5169

Resumo

MELLO, Ivana L. et al. High-cis polybutadiene: viscometric study in toluene and cyclohexane. Polímeros [online]. 2006, vol.16, n.1, pp.53-60. ISSN 0104-1428.  https://doi.org/10.1590/S0104-14282006000100012.

Viscometric measurements, in toluene and cyclohexane solutions, at 30 °C, were carried out on high-cis polybutadiene synthesized with neodymium catalysts. Six different equations were employed to calculate intrinsic viscosity values and viscometric constants: Huggins; Kraemer; Martin and Schulz-Blaschke, by graphic extrapolation; and Solomon-Ciuta; Deb-Chanterjee; and again Schulz-Blaschke, by single point determination. The values obtained for intrinsic viscosity in both solvents and also the molecular weight (in toluene), calculated by applying Mark-Houwink-Sakurada equation, were compared in order to verify the validity of single point determination, which was confirmed. Solomon-Ciuta equation seemed to be suitable for toluene solutions whereas the Deb-Chanterjee equation was adequate for cyclohexane solutions. End-to-end distances of polymeric chains were also determined by applying Flory equation. Based on the higher values of intrinsic viscosity and end-to-end distance of polymeric chains for all samples in toluene, the latter was found to be better solvent than cyclohexane for polybutadiene.

Palavras-chave : Polybutadiene; viscometry; single point determination; end-to-end distance.

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