Surfactants: Characteristics
Chain length and ethoxylation: tuning foam and mildness
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.Buyers specify active content, chain length and distribution, degree of ethoxylation, colour, residual free oil or alcohol, 1,4-dioxane, and performance measures such as critical micelle concentration, foam and cloud point. Hydrophile-lipophile balance (HLB) decides whether a non-ionic is an emulsifier, wetting agent or detergent.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Active matter | LABSA about 96-97%; SLES 28% or 70% paste (indicative) | price per active tonne | indicative |
| Chain length | C12-C14 for detergency and foam; C16-C18 for softeners and emulsifiers (indicative) | performance | indicative |
| Degree of ethoxylation | SLES 1-3 EO; detergent ethoxylates 7-9 EO (indicative) | solubility, mildness, HLB | indicative |
| 1,4-dioxane | below about 10 ppm in personal-care grades (indicative) | regulatory and brand limits | indicative |
| Biodegradability | readily biodegradable (OECD 301) for LAS, SLES and linear ethoxylates (indicative) | EU Detergents Regulation | indicative |
Commercial grades
- LAS/LABSA
- SLS and SLES (1-3 EO)
- Alcohol ethoxylates (fatty and synthetic)
- Nonylphenol ethoxylates (phasing out)
- CAPB and other betaines
- Esterquats and quats
- Alkyl polyglucosides
- Methyl ester sulphonates
- Amino-acid surfactants (glutamates, sarcosinates)
- Rhamnolipids and sophorolipids