Oil-soluble polyalkylene glycols (PAGs) are versatile additives for mineral oil and PAO-based lubricants
Conventional polyalkylene glycols are not miscible with hydrocarbons like mineral oil or polyalphaolefins (PAO), which are the common choice of basis oils in the production of lubricants. The new OSP product line has been developed to offer broad solubility behaviour that will facilitate the formulation of non-polar lubricants as well as improve their performance. OSPs are explicitly not designed as alternative basis oils, but rather to offer the following advantages and properties in the dosing of additives:
- Excellent lubrication
- Improved wear protection
- High polarity and thus strong affinity to metal surfaces
- Intact film of lubricant under high temperatures and loads
- Large viscosity range
- Viscosities ranging from 10 to 66,000 mm/s2
- High inherent viscosity index (VI)
- Very low pour point (-30 to -50 °C)
- Outstanding stability
- Excellent thermal resistance
- High flashpoint
- Hydrolytic stability
Typical applications include:
- Automotive: engine and transmission oil
- Industrial applications: hydraulic and metalworking fluids as well as lubricants for compressors
Residue reduction with PAG technology
The Panel Coker test measures the tendency of an oil to coke on a heated metal surface. The oil is dropped onto a hot surface over a defined period of time and evaluated by the residues it forms. A comparison was made between mineral oil, PAO, and water- and oil-soluble PAGs.
1. Mineral oil group III
2. Polyalphaolefins (PAO)
3. Water-soluble PAGs
4. Oil-soluble PAGs
The oil-soluble PAG tested exhibits the cleanest surface by far. The reduced amount of OSP residues can thus make for a “cleaner” application.
Good solubility behaviour in nonpolar mineral oils and PAO
The following test series reveals the good solubility and broad range of applications for the OSP type GEOlube MCG 2032. 50% GEOlube MCG 2032 and 50% basis oil were mixed at room temperature.
1. MCG 2032 in mineral oil
2. MCG 2032 in PAO 40
3. MCG 2032 in PAO 100
OSP as solubilizer
Oil-soluble PAGs also exhibit good performance as solubility additives.
Adding only 20% GEOlube NNG 2032 allowed 5% VII to be dissolved completely in a PAO 40.