Polyglyceryl esters are usually described with one number - the polymerization degree n in the INCI name. In practice an ester is positioned by three variables: the glycerol polymerization degree n, the number of esterified hydroxyls m, and the fatty tail attached to them. Two of the three are invisible in a CAS number, which is why substitution failures are so common in this family.
Five esters, one table
| INCI | CAS | HLB (supplier) | Typical use |
|---|---|---|---|
| Polyglyceryl-2 Oleate | 49553-76-6; 9007-48-1 | approx. 5.5 | W/O creams, cleansing oils, balms |
| Polyglyceryl-5 Trioleate | family CAS (see note) | approx. 4-5 | W/O creams, balms, color cosmetics |
| Polyglyceryl-10 Pentaoleate | 86637-84-5 | 3.5 (Decaglyn 5-OV datasheet) | High-water W/O, makeup, cleansing oils |
| Polyglyceryl-10 Pentaisostearate | 126449-40-9 | approx. 3.5 | W/O, pigment dispersions |
| Polyglyceryl-10 Pentahydroxystearate | 144747-22-8 | approx. 4.5-5.5 (estimate) | High-water W/O, low-viscosity lotions, sun care |
The oleate ladder shows how the two dials push HLB in opposite directions. On a fixed diglycerol backbone, Polyglyceryl-2 Oleate sits at HLB 5.5 while the tetraester Polyglyceryl-4 Oleate climbs to 8.8 (Sakamoto data): each extra glycerol unit adds free hydroxyls and raises HLB by roughly 1.6 points. Going the other way, NIKKOL's Decaglyn series drops from about 12.9 for Polyglyceryl-10 monooleate to 3.5 for the pentaoleate - each additional oleate ester costs roughly 2 HLB points. Same fatty acid, same backbone family; the ester count is the cheaper and stronger dial.
The tail decides cold behavior and pigment work
- Oleate (C18:1) is the cost-effective default. Its double bond spreads well on skin but is an oxidation entry point - check the iodine value and peroxide value on the COA for hot-fill or long-shelf-life projects.
- Isostearate carries a methyl branch on C18. Packing is disrupted, so the ester stays liquid and amorphous: better cold clarity, less crystallization bloom in sticks, and the wetting behavior pigment houses like for pressed powders and foundations.
- Hydroxystearate (castor-derived, 12-hydroxy) adds one free hydroxyl per tail. Hydrogen bonding raises viscosity and water uptake, which is exactly what a high-internal-phase W/O cream needs; the same OH is why suppliers quote it slightly more hydrophilic than the isostearate at equal ester count (the 4.5-5.5 band above is a structural estimate - always take the number from the datasheet of the lot you buy).
What this means at the purchasing desk
- CAS is a family number here. Some members of the series have no dedicated CAS at all - our Polyglyceryl-5 Trioleate card lists none. An order is only unambiguous with INCI + supplier grade code; adding n and m in words (e.g. "polyglyceryl-10, 5 oleates") removes the last doubt.
- Saponification value is your ester-count check: SV = m x 56,106 / M. A "pentaester" whose SV matches a triester arithmetic is a different product with the same INCI.
- HLB is supplier-specific for polyglyceryl esters (average n and m distributions differ). Compare within one supplier series, never across.
- Standard COA checks: acid value (ester hydrolysis), water content (W/O stability), and for the unsaturated tails a peroxide value on receipt.
For the PEG-free emulsifier fundamentals behind this family, see our earlier guide to polyglyceryl esters as PEG-free emulsifiers; the ester-count logic on PEG-based esters is developed in the PEG ester count guide.
Polyglyceryl-2 Oleate (49553-76-6), Polyglyceryl-5 Trioleate, Polyglyceryl-10 Pentaoleate (86637-84-5), Polyglyceryl-10 Pentaisostearate (126449-40-9) and Polyglyceryl-10 Pentahydroxystearate (144747-22-8) are available from Shanghai Better Chemical with COA, TDS and samples on request.