A Microscopic Study by Dynamic Light Scattering of Four Viscosity Index Improvers in Two Model Solvents and a Mineral Base Oil 932835
Four polymeric viscosity index improvers [PAMA: poly(n-alkyl methacrylate), EP: (ethylene-propylene) copolymer, HPI: hydrogenated poly(isoprene) polymer and SHB: (styrene-hydrogenated butadiene) copolymer], are studied in cyclohexane, n-heptane and a mineral base oil (130 NS). The hydrodynamic diameter of isolated and aggregated polymers is measured by Dynamic Light Scattering technique.
The sample concentrations were always below C* which is the concentration of first overlap separating the dilute regime from the semi-dilute regime. Experiments were run from 20 to 90°C.
Our results show that, depending on the chemical nature of the polymer, the solvent and the temperature value, the solute particles are either aggregated (micelles or not) or isolated.
Citation: Bezot, P., Hesse-Bezot, C., Constans, B., Faure, D. et al., "A Microscopic Study by Dynamic Light Scattering of Four Viscosity Index Improvers in Two Model Solvents and a Mineral Base Oil," SAE Technical Paper 932835, 1993, https://doi.org/10.4271/932835. Download Citation
Pierre Bezot, Christine Hesse-Bezot, Bernard Constans, Dominique Faure, Pierre Hoornaert
Centre National de la Recherche Scientifique, ELF-ANTAR France
International Fuels & Lubricants Meeting & Exposition
Tribological Insights and Performance Characteristics of Modern Engine Lubricants-SP-0996