Study on Relations of High-Pressure Viscosity Properties and the Polymer Behavior of Various Viscosity Index Improver-Blended Oil (Part 2)
Using high-pressure viscosity measurements of 23 kinds of VII-blended oil reported in Part 1, a high-pressure viscosity prediction formula for VII-blended oil was derived. This equation is expressed in a so-called Barus formula, and the pressure-viscosity coefficient is the secant pressure-viscosity...
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| Autores principales: | , |
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| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
Japanese Society of Tribologists
2021
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| Materias: | |
| Acceso en línea: | https://doaj.org/article/47d8042c85bb41c2ba69dffc4e8a8930 |
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| Sumario: | Using high-pressure viscosity measurements of 23 kinds of VII-blended oil reported in Part 1, a high-pressure viscosity prediction formula for VII-blended oil was derived. This equation is expressed in a so-called Barus formula, and the pressure-viscosity coefficient is the secant pressure-viscosity coefficient αB(p)-Bl (= ln(ηpt / ηot) /P) in each ln(ηpt) ‒ P relation curve. The calculation formula of αB(p)-Bl is composed of the corresponding base oil value αB(p)-Bf, the polymer coil itself pressure-viscosity coefficient αPm and the polymer concentration wPm (wt%). In relation to mentioned above, the volume fraction of one polymer molecule in hydrodynamically equivalent sphere, and the volume fraction of the hydrodynamic volume occupied in 100 cm3 of VII-blended oil at critical concentration c* of polymer coil were investigated. It was also found that the viscosity index VIo-Bl in the atmospheric pressure of the VII-blended oil drops with pressure. For this reason, the effect of temperature on the ln(ηpt) ‒ P relation curve, the influence of polymer type and base oil in ηi ‒ P ‒ t relationship, and the influence of polymer type on atmospheric pressure viscosity ηot ‒ t relationship were discussed. |
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