Oleic acid is a kind of organic fatty acid with clear molecular composition. Its molecular formula is C₁₈H₃₄O₂, and the relative molecular weight is 282.46. Each molecule consists of 18 carbon atoms, 34 hydrogen atoms and 2 oxygen atoms, containing one carbon-carbon double bond and one carboxyl group inside the molecular structure.From the chemical classification perspective, oleic acid belongs to monounsaturated fatty acids. It is classified as long-chain aliphatic carboxylic acid, and mostly extracted from natural plant oils instead of synthetic chemical substances.This chemical material has multiple alternative names. Its official systematic chemical name is cis-9-Octadecenoic acid, and it is also commonly called octadecenoic acid in the chemical industry.
Oleic acid possesses stable physical and chemical properties. It is a colorless to pale yellow viscous oily liquid under room temperature. It has a melting point of 13 to 14°C and a boiling point of 360°C. This product is insoluble in water, but can be fully miscible with ethanol, ether, acetone and other conventional organic solvents. With an HLB value of 1, it shows strong lipophilicity. Chemically, it keeps stable under sealed, dark and low-temperature storage conditions, whereas long-term exposure to air will cause oxidation and yellowing.
Thanks to its comprehensive properties, oleic acid has extensive industrial applications. It can be added into cosmetics and personal care products as emollient and raw material. It also serves as high-efficiency lubricant for metal processing and textile auxiliaries for textile production. In addition, it acts as a vital organic synthesis intermediate, widely adopted in coatings, plastics and fine chemical industries.
Parameters
| Melting point | 13-14 °C(lit.) |
| Boiling point | 360 °C |
| density | 0.89 g/mL at 25 °C(lit.) |
| vapor density | 1.03 (vs air) |
| vapor pressure | 52 mm Hg ( 37 °C) |
| refractive index | n20/D1.377 |
| FEMA | 2815 | OLEIC ACID |
| Fp | 133 °F |
| storage temp. | -20°C |
| solubility | Miscible with ethanol, ether, acetone, chloroform, dimethyl formamide and dimethyl sulfoxide. |
| form | Liquid |
| pka | pKa 5.35(H2O,t =25) (Uncertain) |
| Specific Gravity | 0.892 (20/4℃) |
| color | Colorless to pale yellow |
| Odor | Peculiar Lard-Like |
| Odor Type | fatty |
| biological source | plant (Sunflower) |
| Water Solubility | negligible |
| Sensitive | Air Sensitive |
| Merck | 14,6828 |
| JECFA Number | 333 |
| BRN | 1726542 |
| Hydrophilic-Lipophilic Balance (HLB) | 1 |
| Dielectric constant | 2.5（20℃） |
| Stability: | Stable. Combustible. Incompatible with strong oxidizing agents, aluminium. |
| InChIKey | ZQPPMHVWECSIRJ-KTKRTIGZSA-N |
| LogP | 7.698 (est) |
| CAS DataBase Reference | 112-80-1(CAS DataBase Reference) |
| NIST Chemistry Reference | 9-Octadecenoic acid (Z)-(112-80-1) |
| EPA Substance Registry System | Oleic acid (112-80-1) |
Safety information
| Hazard Codes | T,Xi |
| Risk Statements | 23/24/25-34-40-43-36/37/38-38 |
| Safety Statements | 36/37-37/39-26-36-36/37/39 |
| RIDADR | UN 1198 3/PG 3 |
| WGK Germany | 2 |
| RTECS | LP8925000 |
| F | 10 |
| Autoignition Temperature | 363°C |
| TSCA | Yes |
| HS Code | 29161500 |
| Hazardous Substances Data | 112-80-1(Hazardous Substances Data) |
| Toxicity | LD50 i.v. in mice: 230±18 mg/kg (Or, Wretlind) |
