Abstract
Molecular dynamics simulations are used to study the effect of polyisobutylene polymer on the viscosity of polyalphaolefin base oil. The Newtonian viscosities of the solution calculated from simulations at 40 and 100 °C agree with rheometer measurements. The simulations are used to investigate three possible mechanisms by which the polymer may increase solution viscosity. The results indicate that neither (1) coil expansion nor (2) polymer–polymer association underlie viscosity enhancement in the case studied here. Measurements of solvent reorientation close to the additive molecule suggest that (3) modification of the solvent by the additive molecule contributes to viscosity enhancement.
Original language | English (US) |
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Article number | 5 |
Journal | Tribology Letters |
Volume | 66 |
Issue number | 1 |
DOIs | |
State | Published - Mar 1 2018 |
Keywords
- Polyisobutylene
- Polymer association
- Radius of gyration
- Viscosity modifiers
- Viscosity–temperature
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Surfaces and Interfaces
- Surfaces, Coatings and Films