GREASE =
BASE OIL(S) + THICKENER(S) + ADDITIVES

a. Base oils

- Minerals: derived through distillation of the petroleum without synthesis
- Synthetics: derived from chemical synthesis reactions

	Hydrocarboned (PIB, PAO…)
	Oxygenated (esters, glycols, ethers…)
	Miscellaneous
	Halogenated (PFPE…) Silica-containing (silicones) etc.

Mixtures of different base metals are often made, which may or may not belong to the same category.

The properties that differentiate the base oils are mainly:

- intrinsic lubricity
- solvent properties
- temperature stability
- behavior at low temperature (liquid / solid transition)
- viscosity index (translates the viscosity variation according to the temperature)
- ignition point
- biodegradability

b. Thickener

Thickeners are used to obtain the desired viscosity (consistency), thus making it a firm paste that does not flow.
It also contributes to the fundamental properties of the grease: lubrication, anti-wear, extreme pressure, etc.

The thickener can be formed "in situ" by a chemical reaction or be added in the form of an "external" thickener.

	In situ:
	Soaps:	Lithium (Li)
		Calcium (Ca)
		Lithium / Calcium
		"Lithium complex"
	Polyureas
	Calcium sulfonates or "Calcium complexes"
	External:
	Mineral pulverulents (silica gels, bentones, metallic powders…)
	Organic pulverulents (teflon, organic loads…)

c. Additives

Compounds of mineral or organic origin and various functionalities:

- anti-friction
- anti-wear
- extreme pressure
- adhesion
- preservative agents (stabilization of the oil)
- anti-corrosion for lubricated metal surfaces (iron, copper, aluminum…)
- water repellent agents
- colorants, …