TEDA Triethylenediamine CAS 280-57-9

Triethylenediamine (TEDA), with the CAS Number 280-57-9, commonly known as DABCO.

1. Quick Summary

Triethylenediamine (TEDA) is a highly efficient and widely used catalyst for the production of polyurethane foams. It is a diazabicyclic compound with a unique symmetrical, cage-like structure that makes it a strong tertiary amine base. Its primary function is to catalyze the "gelling" and "blowing" reactions in polyurethane formation.

2. Chemical Profile

• IUPAC Name: 1,4-Diazabicyclo[2.2.2]octane

• Common Names:

• Triethylenediamine (TEDA)

• DABCO (from DiAzaBicyclo[Octane])

• CAS Number: 280-57-9

• Molecular Formula: C₆H₁₂N₂

• Molar Mass: 112.17 g/mol

• Appearance: White, crystalline, hygroscopic solid. It often has a characteristic "amine-like" odor.

• Melting Point: 158°C (316°F) - It sublimes (turns directly from solid to vapor) before reaching its boiling point.

3. Key Chemical Structure and Properties

The power of TEDA lies in its unique structure:

• Bicyclic Cage Structure: The molecule has a symmetric, three-dimensional "cage" shape with two nitrogen atoms at opposite corners.

• Tertiary Amines: Both nitrogen atoms are tertiary amines, meaning they have no hydrogen atoms attached. This makes them very strong bases and excellent nucleophiles.

• Sterically Unhindered: The nitrogen atoms are exposed and easily accessible, allowing them to efficiently interact with and catalyze chemical reactions.

Main Properties:

• High Basicity: It is a strong organic base.

• High Catalytic Activity: Its structure allows it to catalyze reactions very efficiently.

• Hygroscopic: It readily absorbs moisture from the air.

• Soluble in water, alcohols, and many other polar solvents.

4. Primary Application: Polyurethane Catalyst

This is the most significant use of TEDA, accounting for the vast majority of its global production.

In polyurethane foam production, two main reactions occur simultaneously:

1. Gelling Reaction: The reaction between an isocyanate (e.g., MDI or TDI) and a polyol to form the polymer urethane linkage. This gives the foam its strength and elasticity.

2. Blowing Reaction: The reaction between an isocyanate and water, which produces carbon dioxide (CO₂) gas. This gas blows bubbles into the polymer, creating the foam's cellular structure.

TEDA's Role:
TEDA is exceptionally good at catalyzing the blowing reaction. It promotes the generation of CO₂ gas, which expands the foam. It also provides a balanced catalysis of the gelling reaction. This balance is crucial for producing foams with the desired density, firmness, and open-cell structure (to prevent the foam from shrinking).

• Used In: Flexible slabstock foams (for mattresses, furniture, car seats), rigid foams (for insulation), and molded foams.

5. Other Applications

Beyond polyurethanes, TEDA is a versatile catalyst and reagent in organic synthesis:

• Organic Synthesis: Used as a ligand in coordination chemistry and as a base catalyst in various reactions like the Baylis-Hillman reaction.

• Pharmaceuticals: Serves as a building block or catalyst in the synthesis of certain drugs.

• Epoxy Resins: Can be used as a catalyst for curing epoxy resins.

• Polymerization: Acts as a catalyst in other polymerization reactions, such as for polyesters.

6. Handling, Storage, and Safety (MSDS Highlights)

Always consult the full Safety Data Sheet (SDS) before handling.

• Hazards:

• Irritant: Causes severe skin and serious eye irritation. Dust is irritating to the respiratory system.

• Flammability: Combustible solid. Dust can form explosive mixtures in air.

• Hygroscopic: Absorbs water and CO₂ from the air, which can degrade its quality.

• Safe Handling:

• Use personal protective equipment (PPE) including safety glasses, gloves, and dust-proof clothing.

• Use adequate ventilation to control dust levels. Avoid creating dust clouds.

• Do not eat, drink, or smoke where this chemical is handled.

• Storage:

• Store in a cool, dry, and well-ventilated place.

• Keep container tightly closed in its original packaging to protect from moisture and air.

• Store away from incompatible materials like strong oxidizing agents and strong acids.

• First Aid:

• Inhalation: Move to fresh air.

• Skin Contact: Wash thoroughly with soap and water.

• Eye Contact: Flush cautiously with water for several minutes. Remove contact lenses if present and easy to do. Seek medical attention.

• Ingestion: Rinse mouth. Do NOT induce vomiting. Seek medical attention.

It is commonly sold as pure crystals (>99%) or, more frequently for the polyurethane industry, dissolved in a carrier liquid like dipropylene glycol (DPG) to create liquid catalysts (e.g., 33% TEDA in DPG) that are easier to handle and meter into foam formulations.

In summary, Triethylenediamine (CAS 280-57-9) is a critical and indispensable workhorse catalyst for the polyurethane industry, valued for its unique structure and powerful, balanced catalytic activity.