Chemical structure of Trimethoxysilylpropylcarbamate-terminated polyether (Manta MS312)

Structural-Grade MS Polymer | Manta MS312

Manta MS312 is a silane-terminated polyether (CAS 216597-12-5) with trimethoxysilylpropylcarbamate end groups, medium activity and medium-high modulus. It is a reactive binder for elastic, moisture-curing adhesives and sealants in automotive engineering, rail vehicles, container construction, flooring and building facades, and is a colorless polymer suitable for clear sealants.

Grade: MS312
Chemical Name: Trimethoxysilylpropylcarbamate-terminated polyether
CAS No.: 216597-12-5
Form: Colorless, transparent viscous liquid

Overview

Manta MS312 is a silane-terminated polyether (STPE, also known as silane-modified polymer, SMP) with trimethoxysilylpropylcarbamate end groups on a polypropylene oxide (PPO) backbone. It is designed as a reactive binder for elastic, moisture-curing adhesives and sealants with medium-high modulus.

On exposure to atmospheric moisture the end groups hydrolyze, releasing a small amount of methanol, and condense to form a durable siloxane network. MS312 combines the processability of a polyether with the weathering resistance and adhesion of silane-crosslinked systems, and it adheres to many substrates, including metals, glass, ceramics and many plastics, often without primer.

MS312 has the same end-group chemistry as Manta MS330A and Manta MS330C, but a lower viscosity, 8,000 – 13,000 mPa·s at 25 °C against 25,000 – 35,000 mPa·s at 25 °C, and medium rather than high activity.

Key Features

Cures at room temperature with amine or organometallic catalysts such as tin, with cure rate set by catalyst type and level
Medium-high modulus for elastic and structural bonding
Colorless, transparent polymer suitable for clear sealants
Good resistance to yellowing and thermal aging
Low viscosity allows high loadings of fillers such as PCC and GCC while maintaining flow
Adheres to metals, glass, ceramics and many plastics, often without primer
Low glass transition temperature helps retain mechanical properties over a wide temperature range

Cross-Reference

Manta MS312 can be considered as an alternative to Wacker GENIOSIL STP-E15.

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

Specifications

Typical properties of Manta MS312
Property	Typical Value
Appearance	Colorless, transparent viscous liquid
Flash Point	237 °C
Viscosity (25 °C)	8,000 – 13,000 mPa·s
Density (25 °C)	1.02 – 1.05 g/cm³
Catalyst Dosage (Tin, on polymer)	1 – 2 %
Activity	Medium
Modulus	Medium-high

Typical values from the current Technical Data Sheet.

Typical Performance of a Reference Sample

MS312 Test Item	Standard	Result
Appearance	Colorless or light yellow, transparent liquid	Colorless, transparent liquid
Viscosity (25 °C), mPa·s	8,000 – 13,000	8,667
pH Value	6 – 9	7
Tensile Strength, MPa	≥ 0.5	0.53
Elongation at Break, %	≥ 50	60
Hardness, Shore A	≥ 35	40

Applications

Elastic and structural adhesives: medium-high-modulus binder for automotive engineering, rail vehicles and container construction
Assembly adhesives: "liquid nail" and high-strength assembly adhesives requiring fast strength build-up
Flooring adhesives: parquet adhesives that require higher movement capability
Construction sealants: paintable, low-VOC sealants for building facades and window installation
Potting and encapsulation: can be evaluated for electronic potting compounds and mold making; shrinkage and electrical properties must be verified in the final formulation
Coatings: reactive binder or additive to improve the scratch resistance and adhesion of industrial coatings, subject to formulation testing

Processing

Moisture sensitivity: the trimethoxysilyl end groups of MS312 hydrolyze and crosslink on contact with water or atmospheric moisture, releasing a small amount of methanol. Store the polymer in tightly sealed containers and process it under moisture-controlled conditions to avoid premature gelation.
Fillers: MS312 can be compounded with common fillers such as precipitated calcium carbonate (PCC), ground calcium carbonate (GCC), fumed silica, quartz flour, diatomaceous earth and aluminum hydroxide. The polymer content can be adjusted to the required properties.
Drying: dry all fillers thoroughly before compounding. Vinyltrimethoxysilane (VTMO) is recommended as a water scavenger.
Plasticizers: suitable plasticizers include phthalates (e.g., DINP, DIDP), DOTP and low-molecular-weight polyethers (PPG).
Additives: adhesion promoters, antioxidants, fungicides and UV/light stabilizers can be added to adjust the end-use properties.

Reference Formulation

Component	Parts by Weight	Example / Function
Manta MS312	30 - 40	Silane-terminated polymer (binder)
Plasticizer	10 - 20	PPG, DINP, or DOTP
Water Scavenger	1 - 2	Vinyltrimethoxysilane (VTMO)
Thixotropic Agent	2 - 5	Fumed Silica (Hydrophilic or Hydrophobic)
Fillers	40 - 50	Ground Calcium Carbonate (GCC) / TiO2
Antioxidants and UV-stabilizers	0.1 - 2	Hindered Phenols (AO) / HALS (UV)
Adhesion Promoter	1 - 2	Amino-silanes (e.g., AMEO, AMMO)
Catalyst	0.3 - 0.6	Organotin (DBTDL) or Tin-free alternatives

Related applications: Adhesives & Sealants

Packaging & Storage

50 kg plastic drum with aluminum-foil liner bag;

200 kg drum with aluminum-foil liner bag;

1,000 kg IBC (tote);

Other pack sizes available on request.

Safety and Storage

Store in the tightly closed original container in a cool, dry place, protected from moisture and direct sunlight. Shelf life: 24 months from the date of production when stored as recommended. The product is classified as non-hazardous. Refer to the current Safety Data Sheet (SDS) for safety, handling and transport information.

Note: The values in this data sheet are typical values and are not intended for use in preparing specifications. Users should test the product to determine its suitability for their specific application.

Documents

Technical Data Sheet · PDF Download TDS
SDS and COA · on request Request Documents

Frequently Asked Questions

How much catalyst does an MS312 formulation need?

Tin catalyst dosage is 1 – 2 % on polymer. The reference formulation uses 0.3 - 0.6 parts by weight of organotin (DBTDL) or tin-free catalyst against 30 - 40 parts of MS312. MS312 also cures with amine catalysts, and the cure rate is adjusted via catalyst type and level.

What does a typical MS312-based sealant formulation look like?

The reference formulation uses 30 - 40 parts by weight of MS312, 10 - 20 parts of plasticizer (PPG, DINP or DOTP) and 40 - 50 parts of ground calcium carbonate or TiO2 filler. It also contains a water scavenger, thixotropic agent, stabilizers, adhesion promoter and catalyst; the full recipe is in the Reference Formulation table on this page.

Should I choose MS312 or MS330C for a trimethoxysilane-terminated binder?

Both have the same end-group chemistry, CAS 216597-12-5 and a medium-high modulus. MS312 has medium activity and a viscosity of 8,000 – 13,000 mPa·s at 25 °C, while MS330C has high activity and a viscosity of 25,000 – 35,000 mPa·s at 25 °C. MS312 suits formulations that need a lower-viscosity binder and high filler loading; MS330C suits formulations that need fast skin formation.

What does MS312 release as it cures?

On contact with water or atmospheric moisture, the trimethoxysilyl end groups hydrolyze and crosslink, releasing a small amount of methanol. Store the polymer in tightly sealed containers and process it under moisture-controlled conditions to avoid premature gelation.

How long can Manta MS312 be stored?

Need a finished adhesive or sealant rather than the polymer? See our custom MS adhesives and sealants service.

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