Stearyl Triethoxysilane is a chemical compound consisting of stearylic acid and silanes. An organosilicon compound used as a surface-modifying agent and as a component in cosmetic and industrial formulations. It combines the properties of stearyl alcohol with the functionality of silane.
The name describes the structure of the molecule:
- Stearyl refers to stearyl alcohol, a fatty alcohol derived from long-chain fatty acids. Fatty alcohols like stearyl are known for their emollient and conditioning properties.
- Triethoxysilane indicates that the compound contains a triethoxysilated silane group. Silanes are silicon compounds, and in this case, the triethoxysilane is bonded to stearyl alcohol. This modification imparts unique properties related to the silicon structure.
Raw Materials and Their Functions
Stearyl Alcohol. A fatty alcohol used as the base for the production of stearyl triethoxysilane. It provides the lipid component of the compound.
Triethoxysilane. A silane precursor that reacts with stearyl alcohol to form the final product.
Industrial Chemical Synthesis of Stearyl Triethoxysilane
- Silanization Reaction. Reaction of stearyl alcohol with triethoxysilane. During this reaction, chemical bonds are formed between the stearyl alcohol and the silane group.
- Reaction Control. The silanization reaction is monitored to ensure it occurs correctly and the final product has the desired properties.
- Purification. After the reaction, stearyl triethoxysilane is purified to remove impurities and by-products.
- Quality Control and Packaging. The purified stearyl triethoxysilane undergoes quality checks to ensure it meets the required standards. After quality control, it is packaged for use in cosmetic and industrial products, where it utilizes its properties as a surface-modifying agent and functional component.
It appears as a white powder or colourless liquid.
Incompatible with water, acids, strong oxidizing agents. Stable. Moisture sensitive.

What it is used for and where
Cosmetics
Surface Modifier
A substance that has the property of preventing surface defects in the epidermis by repelling oils and water and giving the skin greater resistance against blemishes. Provides the epidermis with the humectant properties of silanes and a soft skin feel by helping the formulation to adhere better to the skin.
The most relevant studies on this ingredient have been selected with a summary of their contents:
Stearyl Triethoxysilane studies
Caratteristiche tipiche del prodotto commerciale Stearyl Triethoxysilane powder
| Appearance | White powder |
| Boiling Point | 321.6±10.0°C at 760 mmHg |
| Melting Point | 10-12°C |
| Flash Point | 166.1±21.8 °C |
| Density | 0.9±0.1 g/cm3 |
| Refraction Index | 1.443 |
| PSA | 27.69000 |
| Vapor Pressure | 0.0±0.7 mmHg at 25°C |
| Size | 60-100/80-120/100-200/200-300/230-400/300-400m |
| Percentage of Particles | 4.0 <10um |
| Average Particle Size | 49-65 um |
| Carbon Loading | 17-19 |
| Surface Area | 290-310 m2/g |
| Average Pore Size | 99-105 Å |
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- Molecular Formula C24H52O3Si
- Molecular Weight 416.8
- Exact Mass 416.368561
- CAS 7399-00-0
- UNII 1VN9P25L8H
- EC Number 230-995-9 231-545-4
- DSSTox Substance ID DTXSID90224778
- IUPAC triethoxy(octadecyl)silane
- InChl=1S/C24H52O3Si/c1-5-9-10-11-12-13-14-15-16-17-18-19-20-21-22-23-24-28(25-6-2,26-7-3)27-8-4/h5-24H2,1-4H3
- InChl Key FZMJEGJVKFTGMU-UHFFFAOYSA-N
- SMILES CCCCCCCCCCCCCCCCCC[Si](OCC)(OCC)OCC
- MDL number MFCD00039875
- PubChem Substance ID 329778430
Synonyms:
- n-Octadecyl Triethoxysilane
- Silane, triethoxyoctadecyl-
- Octadecyltriethoxysilane
- triethoxy(octadecyl)silane



