The Silicone oil family is a group of synthetic polymers that combine an inorganic silicon-oxygen backbone with organic side chains, which can include methyl, phenyl and trifluoropropyl. Variations on the chemical structure affect the properties. Silicones are also called Polysiloxanes. Poly(dimethylsiloxane) are the most common silicone used commercially. PAO summary:
- Temperature range of -70 to 200°C
- Excellent plastic and elastomer compatibility (except when used on other silicone materials)
- Wide viscosity range available
- Low pour points (less than -80°C)
- Poor film strength so poor load carrying capability
- Low surface tension
- Can migrate easily
- High Viscosity Index (VI) silicones are available, from 300 to 800
Keep in mind that if a Silicone is used as the base oil for a grease, the thickener and additives also used in the formula will have an influence on the final characteristics and performance of the finished grease/lubricant.
Take a look at our typical thickener systems characteristics used to make a base oil into a grease.