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Chemical structure of [(Methylcarbamato)methyl]dimethoxymethylsilane (Manta AM121)
Water Scavengers

Alpha Silane Water Scavenger & Chain Extender | Manta AM121

Manta AM121 is [(methylcarbamato)methyl]dimethoxymethylsilane (CAS 23432-65-7), an alpha silane used as a water scavenger and chain extender in moisture-curing STP/MS polymer, 1K polyurethane and hybrid adhesives and sealants. The alpha effect gives fast reaction with moisture, while the dialkoxy structure builds flexible, low-modulus elastomers.

Grade
AM121
Chemical Name
[(Methylcarbamato)methyl]dimethoxymethylsilane
CAS No.
23432-65-7
Formula
C6H15NO4Si
Synonyms
[(Dimethoxymethylsilyl)methyl]-O-methylcarbamate; Methyl N-[[(dimethoxy)(methyl)silyl]methyl]carbamate
Form
Colorless Transparent Liquid
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Overview

Manta AM121 is an alpha-organofunctional silane in which the nitrogen atom is separated from the silicon atom by a single methylene group. This proximity induces the alpha effect, which makes its methoxy groups highly reactive toward moisture compared with conventional gamma-silanes.

Because it combines this reactivity with a bifunctional (dialkoxy) structure, AM121 acts as both a water scavenger and a chain extender. During compounding and packaging it reacts with trace moisture, which extends the shelf life of moisture-sensitive formulations. During cure it acts as a linear chain extender rather than a 3D crosslinker, which lowers the degree of crosslinking and gives flexible, low-modulus products.

For a conventional moisture scavenger, compare Manta V31, a vinyl-functional trimethoxysilane. V31 carries three hydrolyzable methoxy groups, while AM121 carries two and adds chain extension to the drying function, so AM121 is the grade to evaluate when the cured sealant must remain low in modulus.

Key Features

  • Alpha-effect methoxy groups react immediately with trace moisture
  • Water scavenging during compounding and packaging extends shelf life
  • Dialkoxysilyl structure acts as a linear chain extender rather than a 3D crosslinker
  • Lower degree of crosslinking for flexible, low-modulus elastomers
  • Fast curing on exposure to atmospheric moisture at room temperature
  • No heavy metal catalyst such as tin needed for curing

Cross-Reference

Manta AM121 can be considered as an alternative to Wacker GENIOSIL XL 65.

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

Specifications

Typical properties of Manta AM121
PropertyTypical Value
Molecular Weight193.27
AppearanceColorless Transparent Liquid
Density (ρ20°C, g/cm³)1.05-1.15
Refractive Index (n25/D)1.4300-1.4400
Purity≥95%

Typical values from the current Technical Data Sheet.

Applications

  • Silane-terminated polymers (STP/MS): moisture scavenging during production of formulations based on highly reactive silane-modified polymers, such as alpha-STP systems, while improving the flexibility of the cured sealant
  • High-movement sealants: expansion joint sealants in construction and automotive applications that require low modulus and high elongation
  • Adhesives: moisture-curing polyurethane (1K PU) and hybrid adhesive systems, reducing outgassing and extending pot life and shelf life

Related applications: Adhesives & Sealants

Packaging & Storage

Supplied in 500 g, 1000 g, 25 kg pail, 200 kg drum.

Safety and Storage

Storage Conditions: Keep tightly closed in a cool, strictly dry, and well-ventilated area. Protect from direct sunlight and ambient moisture. Premature exposure to humidity will trigger rapid hydrolysis.

Shelf Life: Minimum 9 months when stored in the original, unopened containers under proper conditions.

Transportation: Shipped as a non-hazardous substance according to transport regulations.

Documents

Frequently Asked Questions

What makes Manta AM121 faster than conventional gamma-silane water scavengers?

Its nitrogen atom sits only one methylene group away from silicon, which produces the alpha effect. The methoxy groups become highly reactive toward moisture and react immediately with trace water during compounding and packaging, extending the shelf life of the formulation.

Will Manta AM121 stiffen my cured sealant?

It is designed to do the opposite. Its dialkoxy (bifunctional) structure makes it act as a linear chain extender rather than a 3D crosslinker during cure, which lowers the degree of crosslinking and gives flexible, low-modulus elastomers suited to high-movement expansion joint sealants.

Does Manta AM121 require a tin catalyst to cure?

No. It cures very rapidly on exposure to atmospheric moisture at room temperature without the need for heavy metal catalysts such as tin. Confirm the cure profile in your own formulation.

How long does Manta AM121 keep, and how should it be stored?

Keep tightly closed in a cool, strictly dry, and well-ventilated area. Protect from direct sunlight and ambient moisture. Premature exposure to humidity will trigger rapid hydrolysis. Shelf life is a minimum of 9 months in the original, unopened containers under proper conditions.

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

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