Mineral oil-based grease
Most of the greases used today are based on mineral oil.
Synthetic oil-based grease
Synthetic oil grease is used for certain conditions where conventional mineral oil grease fails (in low-temperature properties, heat resistance, low-torque property, or longer life). Synthetic greases come in many different characteristics depending on the type of oil used.
Ester oil-based grease (diester, polyol ester, etc.)
Provides excellent lubricity; Usable over a wide temperature range from very low to very high; Tends to swell rubber.
Synthetic hydrocarbon oil-based grease
Usable over a wide temperature range from very low to very high; Good rubber/plastic compatibility (because of the absence of polar group in the hydrocarbon molecular structure) except natural rubber and EPDM.
Polyethylene glycol oil-based grease
Optimum for applications in contact with rubber because of little adverse effect on rubber including natural rubber and EPDM.
Phenyl ether oil-based grease
Optimum for automotive electrical components for its excellent thermo-oxidative stability and good radiation resistance.
Silicone oil-based grease
Excellent thermo-oxidative stability and usable over a wide temperature range; Poor steel-on-steel lubricity.
Fluorinated oil-based grease
Offers the best thermo-oxidative stability and high chemical resistance of all existing greases, but has the drawback of being very expensive. Optimal for chemical plants, high-temperature drying ovens, and copying machine heat rollers.
Comparison of properties of grease due to base oil
| mineral oil diester polyol | ol ester oil hydrocarbon | n oil polyethylene | e glycol oil phenyl | l ether oil silicone | e oil fluorinated | d oil chemical | |||
|---|---|---|---|---|---|---|---|---|---|
| l structural formulas (typical) | mixed hydrocarbon |  |
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| Performance | Oil typed | d viscosity paraffinio | DOS | mid viscosity PET | mid viscosity PAQ | mid viscosity PPG | ADE | dimethyl silicone middle | d viscosity PFAE |
| Lubricity (oiliness) | G | E | E | G | F | G | P | G | |
| Heat resistance | P | F | G | G | G | E | O | O | |
| Oxidative stability | P | F | G | G | F | E | O | O | |
| Low-temp. property | F | O | E | E | G | G | O | G | |
| Rubber compatibility | F | P | P | E | O | G | O | O | |
| Plastic compatibility | F | P | P | E | P | E | O | O | |
| Remarks | low cost poorer | r rubber compatibility good | d rubber compatibility except natural rubber and EPDM | good rubber compatibility including natural rubber and EPDM | excellent radiation resistance poorer | r steel – on – steel boundary lubricity best | t chemically stable of all existing greases; very costly | ||
O: Outstanding E: Excellent G: Good F: Fair P: Poor
