Description

n-Octadecylmethyldiethoxysilane is a high-purity organosilicon compound, specifically a long-chain alkyl alkoxysilane, widely used as a surface modifying agent. Its primary value lies in its ability to impart hydrophobic and oleophobic properties to inorganic substrates, enhancing material compatibility and performance. This silane is essential for manufacturers in the coatings, plastics, and advanced materials industries seeking to improve the dispersion, adhesion, and durability of their products.

Application

• Surface Treatment for Fillers and Pigments: Acts as a coupling agent to modify the surface of silica, calcium carbonate, and other mineral fillers, improving their compatibility with polymer matrices like polyolefins and engineering plastics.
• Hydrophobic Coatings: Used as a precursor for creating water-repellent and anti-fouling coatings on glass, metals, and ceramics.
• Rubber and Silicone Elastomers: Functions as a crosslinking agent or processing aid to enhance mechanical properties and reduce viscosity during compounding.
• Adhesives and Sealants: Improves adhesion to difficult substrates and provides enhanced moisture resistance in formulated products.
• Fiber and Textile Treatment: Imparts durable water repellency (DWR) and stain resistance to synthetic and natural fibers.
• Nano-material Modification: Used to functionalize nanoparticles (e.g., silica, titania) to prevent agglomeration and facilitate dispersion in organic solvents and polymers.

Basic Information

Item	Details
Product Name	n-Octadecylmethyldiethoxysilane
CAS No.	67859-75-0
Molecular Formula	C23H50O2Si
Molecular Weight	386.73 g/mol
Synonyms	Octadecylmethyldiethoxysilane; Methyloctadecyldiethoxysilane; Diethoxy(octadecyl)methylsilane; n-Octadecyl(methyl)diethoxysilane; C18-Methyldiethoxysilane; Stearylmethyldiethoxysilane; Silane, diethoxy(octadecyl)methyl-; (Octadecyl)methyldiethoxysilane
EINECS	Contact for details

Quality Control

Our n-Octadecylmethyldiethoxysilane is manufactured under strict quality management systems. Each batch undergoes rigorous analytical testing, including Gas Chromatography (GC) and Nuclear Magnetic Resonance (NMR), to ensure high purity and consistent performance. Certificates of Analysis (COA) detailing purity, identity, and key physical properties are provided with every shipment and are available upon request.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). This material is hygroscopic (moisture-sensitive); containers must be kept tightly sealed to prevent degradation from atmospheric moisture.

Specification

Item	Specification
Appearance	Colorless to pale yellow liquid
Identification (IR)	Conforms to structure
Assay (GC)	≥ 97.0%
Refractive Index (n20/D)	1.440 - 1.445
Density (g/mL, 25°C)	0.86 - 0.88

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.