N-Octyltriethoxysilane Oligomer silane Oligomer CAS 2943-75-1 water repellent

Product Overview of N-Octyltriethoxysilane Oligomer

N-Octyltriethoxysilane oligomer, designated as Siwin-O9832, is an oligomeric silane hydrolysate engineered for penetrating water-repellent treatment of mineral building substrates. Unlike monomeric octyltriethoxysilane, the oligomeric form consists of partially hydrolyzed and condensed siloxane chains that deliver deeper and more uniform penetration into porous materials while releasing lower volumes of alcohol during the curing reaction.

Oligomeric Silane Hydrolysate Structure

The oligomer is produced through controlled hydrolysis and condensation of n-octyltriethoxysilane, resulting in a mixture of linear and branched siloxane oligomers with residual ethoxy groups available for further reaction. The octyl functional group provides hydrophobic character, while the siloxane backbone forms covalent bonds with hydroxyl groups on mineral surfaces. This pre-condensed structure reduces the amount of ethanol released during field application compared with monomeric silanes, supporting lower-VOC formulation strategies for commercial users.

Technical Specifications of Octylsilane Oligomer Water Repellent

Typical Physical Properties

Industrial Applications of Silane Oligomer Water Repellent

Concrete and Masonry Hydrophobic Treatment

Siwin-O9832 is formulated into penetrating water repellents for concrete, brick, stone, and other cementitious substrates. Applied as a dilute solution, the oligomer penetrates into the capillary pore structure and reacts with surface hydroxyl groups to form a covalently bonded siloxane network. This treatment renders the substrate hydrophobic, significantly reducing water absorption while maintaining vapor permeability. Commercial buildings, parking structures, and bridge decks treated with oligomeric silane water repellents show reduced water ingress and lower chloride ion penetration rates.

Filler and Pigment Surface Modification

Beyond construction protection, n-octyltriethoxysilane oligomer serves as a surface treatment agent for mineral fillers and pigments used in polymer composites and coatings. The silane oligomer coats particle surfaces, improving compatibility between inorganic fillers and non-polar polymer matrices such as polyolefins. This surface modification enhances filler dispersion, reduces viscosity in filled systems, and improves mechanical properties of the final composite, supporting more efficient production operations for manufacturing clients.

Construction Waterproofing Scenarios

Typical commercial applications include facade impregnation for commercial buildings, parking deck water protection, highway bridge concrete treatment, and historic masonry preservation. The oligomeric form is particularly suited for projects requiring deeper penetration into dense concrete or for applications where lower alcohol emissions during application are specified by environmental regulations governing construction site operations.

Application Methods and Dilution Guidelines

Recommended Dilution Ratios

Siwin-O9832 may be diluted with appropriate solvents including alcohols, aliphatic hydrocarbons, and low-molecular-weight siloxanes to achieve target application concentrations. Common dilution levels range from 20% to 40% active content, depending on substrate porosity and desired penetration depth. Higher concentrations are used for dense concrete substrates, while lower concentrations suit more porous masonry materials.

Application Techniques

Application is typically performed by brush, roller, or low-pressure spray equipment. For vertical surfaces, two coats applied wet-on-wet ensure uniform coverage without runoff. The treated substrate develops hydrophobic properties as the silane reacts with surface moisture and mineral hydroxyl groups. On new concrete with alkaline pH, the reaction proceeds more rapidly due to catalytic effects of the cementitious environment.

Packaging, Storage and Safety

Siwin-O9832 is supplied in 200L steel drums and 1000L IBC containers, with custom packaging available upon request. The product should be stored in tightly sealed containers under cool, dry conditions away from moisture and direct sunlight. Proper handling requires adequate ventilation and personal protective equipment, as the material may cause skin and eye irritation. Full safety information is provided in the corresponding Safety Data Sheet for enterprise customers.

FAQ About N-Octyltriethoxysilane Oligomer

What is the difference between oligomeric and monomeric octyltriethoxysilane?

Oligomeric octyltriethoxysilane is a partially pre-hydrolyzed and condensed form of the monomer. It contains siloxane chains rather than single silane molecules, resulting in deeper and more uniform substrate penetration and lower alcohol release during application compared with the monomeric version.

How does silane oligomer water repellent work on concrete?

When applied to a mineral substrate, the silane oligomer penetrates into the capillary pores and reacts with surface hydroxyl groups, forming a covalently bonded hydrophobic siloxane network. This network reduces water absorption while allowing water vapor to pass through, preserving the breathability of the treated material.

What substrates are suitable for treatment with Siwin-O9832?

Siwin-O9832 is suitable for concrete, brick, natural stone, mortar, and other cementitious or mineral substrates commonly encountered in commercial construction and infrastructure projects.

What dilution ratio is recommended for concrete impregnation?

For most concrete applications, a dilution ratio of 20% to 40% active content is recommended. Dense concrete substrates may require higher concentrations, while more porous masonry typically performs well at lower dilution levels.