"Methyltrimethoxysilane (MTMS, CAS 1185-55-3) is a key organosilane used in surface treatment, crosslinking, and polymer modification. Learn about its properties, applications, and how to source high-quality MTMS."
-Deshangchemical-chemechemi
Methyltrimethoxysilane (MTMS), also known as trimethoxy(methyl)silane, is one of the most widely used organosilicon compounds in modern chemical industry. With the CAS number 1185-55-3 and molecular formula CH₃Si(OCH₃)₃, this reactive Methyltris compound plays a critical role in surface modification, polymer synthesis, and adhesion promotion.
Chemical Properties of Methyltrimethoxysilane
MTMS is a colorless to slightly yellow transparent liquid with a characteristic odor. Key physical properties include:
Molecular Weight: 122.19 g/mol
Boiling Point: 102–104°C
Density: 0.955 g/mL at 25°C
Flash Point: 8°C (highly flammable)
Refractive Index: 1.370
As a trifunctional Methyltris silane, MTMS hydrolyzes readily in the presence of water to form silanol groups, which then condense to create siloxane networks. This hydrolysis-condensation mechanism is fundamental to its utility as a crosslinker and surface treatment agent.
Key Applications of MTMS (CAS 1185-55-3)
1. Crosslinker for RTV Silicone Rubber
Methyltrimethoxysilane is extensively used as a crosslinking agent in room-temperature vulcanizing (RTV) silicone sealants and coatings. It reacts with silanol-terminated polydimethylsiloxane (PDMS) to form moisture-curable systems, improving tensile strength, elongation, and weathering resistance.
2. Surface Treatment Agent
MTMS modifies inorganic substrates such as glass fibers, silica fillers, and mineral surfaces. By creating hydrophobic siloxane coatings, it dramatically improves the compatibility between inorganic fillers and organic polymer matrices in composites and reinforced plastics.
3. Silane Coupling Agent
As a Methyltris-type silane coupling agent, MTMS bridges organic and inorganic materials, enhancing mechanical properties and moisture resistance in fiber-reinforced composites, adhesives, and coatings.
4. Synthesis Intermediate
MTMS serves as a key precursor in the synthesis of methylsilsesquioxane (MSQ) resins, organosilica hybrid materials, and sol-gel coatings for electronics and optical applications.
Industry Applications
Construction: Waterproofing agents, facade coatings, and stone consolidation treatments
Electronics: Low-k dielectric materials, encapsulants, and protective coatings
Automotive: Rubber seals, gaskets, and under-hood components
Textiles: Hydrophobic finishing for technical fabrics and apparel
Paints & Coatings: Crosslinker in high-performance silicone coatings
Storage and Handling
Due to its low flash point, Methyltrimethoxysilane should be stored in tightly sealed containers away from heat, sparks, and moisture. Ideal storage conditions: cool, dry, well-ventilated area at temperatures below 30°C. Avoid contact with water to prevent premature hydrolysis.
Why Choose Deshang Chemical for MTMS?
Shandong Deshang Chemicals Co., Ltd. supplies high-purity Methyltrimethoxysilane (CAS 1185-55-3) with a minimum purity of 99%. Our competitive pricing, reliable supply chain, and technical support make us the preferred Methyltris silane supplier for customers in Europe, Southeast Asia, the Middle East, and beyond. Contact us for specifications, COA, and bulk pricing.
