A Monsanto Automatic Capillary Rheometer and a sliding plate rheometer were used to study the spurt phenomenon and to discover whether it is the result of a system instability or a material property. The capillary rheometer has been the only instrument able to operate at spurt stresses up to present time, because capillary rheometers operate at shear stresses that are out of the range of rotational shear rheometers. However, a sliding plate rheometer can generate shear stresses in the spurt range. A comparative study using two linear polybutadiene samples at 50°C was carried out using these two rheometers. Special attention was paid to the evaluation of the actual pressure drop in the capillary in order to determine the true shear stress at the wall. It was found that spurt occurs only in the capillary rheometer. In other words, the flow curve generated by the sliding plate rheometer is continuous in the shear stress range where spurt is observed in the capillary rheometer. Slip velocities were determined using data from the two rheometers, and the slip velocities for the post-slip capillary flow all fall on the smooth curve based on sliding plate data, provided that the pressure drop in the capillary, and not the overall driving pressure, is used to calculate the wall shear stress.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.81570 |
| Date | January 2004 |
| Creators | Smillo, Fabricio |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Chemical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002174998, proquestno: AAIMR06587, Theses scanned by UMI/ProQuest. |
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