Skip to content
Manta logo MANTA
Chemical structure of n-Dodecyltrimethoxysilane (Manta L1231)
Silanes & Alkyl Silanes

N-Dodecyltrimethoxysilane (C12) | Manta L1231

Manta L1231 is n-dodecyltrimethoxysilane (CAS 3069-21-4), a C12 linear alkyl silane used in water repellents for natural stone, concrete and sensitive masonry, including cultural heritage conservation, and for mineral filler modification and mold release. Its heavier chain lowers volatility and gives a more controlled penetration depth than shorter-chain silanes.

Grade
L1231
Chemical Name
n-Dodecyltrimethoxysilane
CAS No.
3069-21-4
EINECS
221-332-4
Formula
C15H34O3Si
Synonyms
(Trimethoxysilyl)dodecane
Form
Colorless transparent liquid
Request a Sample Download TDS

Overview

Manta L1231 is a monomeric long-chain alkyl functional silane, chemically identified as n-dodecyltrimethoxysilane. Its 12-carbon (C12) linear alkyl chain gives strong hydrophobicity and good weather resistance (UV stability).

Compared with shorter-chain silanes such as C8 or C10 types, the heavier molecular structure significantly reduces volatility and provides a moderate, highly controlled penetration depth. This suits L1231 to treating sensitive substrates and to long-lasting surface modification that does not alter natural breathability or aesthetics.

L1231 releases methanol on hydrolysis. Its triethoxy counterpart, Manta L1232, has the same C12 chain with a more moderate hydrolysis rate and releases ethanol. For a shorter C8 methoxy grade, see Manta L310.

Key Features

  • 12-carbon linear chain for strong hydrophobicity and good UV stability
  • Lower volatility than shorter-chain silanes
  • Moderate, highly controlled penetration depth for sensitive substrates
  • Retains water vapor permeability and original appearance
  • Improves the dispersibility, compatibility and hydrophobicity of inorganic fillers and pigments
  • Low surface energy from the long non-polar chain, useful for semi-permanent mold release

Cross-Reference

Manta L1231 can be considered as an alternative to Wacker GENIOSIL DD-Trimethoxy.

Trademarks are the property of their respective owners; no affiliation is implied.

Specifications

Typical properties of Manta L1231
PropertyTypical Value
Molecular Weight290.52
AppearanceColorless transparent liquid
Purity (by GC, %)98.0 min
Specific Gravity (ρ20°C, g/cm3)0.885~0.895
Refractive Index (nD 25°C)1.4220~1.4320

Typical values from the current Technical Data Sheet.

Applications

  • Cultural heritage conservation: very low volatility, controlled penetration and a durable hydrophobic network for the protection and restoration of historical monuments, artifacts and highly sensitive porous masonry
  • Natural stone and concrete protection: deep, long-lasting water repellency for natural stone, masonry and concrete while retaining water vapor permeability and original appearance
  • Mineral filler modification: improves the dispersibility, compatibility and hydrophobicity of inorganic fillers and pigments in non-polar plastics, rubbers and resin matrices
  • Coatings, adhesives and sealants: additive that improves moisture resistance and interfacial adhesion
  • Mold release: semi-permanent release agent in various molding processes, owing to the strong non-polar nature and low surface energy of the C12 chain

Related applications: Concrete, Masonry & Stone Protection · Paints & Coatings · Plastics & Masterbatches

Packaging & Storage

Supplied in 20 kg pail, 180 kg drum and 900 kg IBC.

Safety and Storage

Highly Reactive & Methanol Release: Manta L1231 reacts with water and atmospheric moisture to form cross-linked polysiloxanes. CRITICAL WARNING: This hydrolysis reaction releases METHANOL as a toxic and highly flammable byproduct. Strictly ensure excellent local exhaust ventilation during formulation, application, and curing to prevent vapor accumulation.

Storage Conditions: Store in a cool, dry, and well-ventilated area strictly away from open flames and moisture. Keep containers hermetically sealed at all times to prevent premature moisture cross-linking.

When stored at or below 35°C in the original unopened containers, the shelf life is 12 months from the date of production. Not regulated as dangerous goods for transport; refer to the Safety Data Sheet for hazard classification and safe handling.

Documents

Frequently Asked Questions

Why is Manta L1231 recommended for cultural heritage conservation?

Its very low volatility, controlled penetration and durable hydrophobic network suit the protection and restoration of historical monuments, artifacts and highly sensitive porous masonry, while retaining water vapor permeability and the original appearance.

How does the C12 chain of L1231 change penetration behavior compared with shorter-chain silanes?

Compared with C8 or C10 silanes, the heavier C12 molecular structure significantly reduces volatility and provides a moderate, highly controlled penetration depth, which is useful on sensitive substrates.

What safety measure is critical when applying L1231?

Its hydrolysis releases methanol, a toxic and highly flammable by-product. Ensure local exhaust ventilation during formulation, application and curing, and keep containers hermetically sealed away from moisture and open flames.

Looking for a different purity, functional group, or a structure not listed here? Contact our technical team.

Talk to our technical team

Tell us your application, target properties and estimated quantity. We will suggest grades and arrange documents or samples.

Send an Inquiry Request a Sample