Additives, Lubricants | Viscosity Testing of Lubricant Additives with SVM 3001

Base oils are usually not good enough for direct application as lubricants. To tailor base oils for their intended purpose, they are mixed with additives. Depending on the additive package, the obtained formulated oil can then be used as crankcase lubricant, gear oil, industrial lube oil etc.
Additives are used to:

• protect machinery components from corrosion and wear
• improve thermal stability, shear stability and resistance against corrosion
• handle contaminants such as soot, humidity and acids
• extend the service lifetime of the lubricant
• improve fuel efficiency and load handling

To achieve all these properties, various additive types are required:

• Viscosity Index Improvers (VII, e.g. polymethacrylates PMA or olefin copolymers OCP)
• pour point depressants (e.g. alkylated aromatics)
• friction modifiers (e.g. molybdenum compounds)
• detergents and dispersants (e.g. PIB / PIBSA)
• corrosion inhibitors (e.g. benzotriazoles or amine phosphates)
• anti-wear agents (e.g. ZDDP zinc dialkyl dithiophosphate)
  and others.

Additives are produced single-origin or in packages for oil blenders to obtain lube oils with different properties. But also for end-customers, ready-to-use packages are available from automotive accessories suppliers to improve e.g. the properties of the engine oil.

Parameters

Besides other specifications such as shear stability, molecular weight, pour point, solubility, density or specific gravity, kinematic viscosity at 100 °C is a key property of viscosity index improvers, but also for many other additives such as friction reducers, corrosion inhibitors and others.
Solid VII polymers are dissolved in base oil in a defined concentration prior to testing the viscosity. In addition to measuring the kinematic viscosity, the VI of different additive concentrations in the blended oil is commonly tested.