Rheological Properties of Polyethylene Glycol (PEG 35000): An Interpretation of a Negative Intrinsic Viscosity and a High Huggins Coefficient Value |
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| Authors: | K. Bechekh N. Ghaouar |
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| Affiliation: | 1. Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, Faculté des Sciences de Tunis , Université El Manar , Tunis , Tunisia;2. Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, Faculté des Sciences de Tunis , Université El Manar , Tunis , Tunisia;3. Institut National des Sciences Appliquées et de Technologie , INSAT, Centre Urbain Nord , Tunis , Tunisia |
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| Abstract: | The effect of temperature on the intrinsic viscosity and the Huggins coefficient of polyethylene glycol (PEG 35000) in aqueous solution was studied. The intrinsic viscosity became negative for temperatures higher than 45°C. Two hypotheses are given to explain this tendency. We demonstrated that the mobility and size of the PEG molecules did not give full information concerning the causes of the negative intrinsic viscosity values. The Huggins coefficient variation was also studied. A peak around 45°C was observed where only the hydrodynamic interactions were present, confirming the transition from a soft to a hard sphere conformation. Above 45°C, the decrease of the Hugging coefficient showed that attractive interactions were responsible for the negative intrinsic viscosity values. |
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| Keywords: | Huggins coefficient intrinsic viscosity polyethylene glycol rheology |
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