Trimethylolpropane (TMP) CAS 77-99-6

Trimethylolpropane (TMP) – Trifunctional Alcohol for High-Performance Polymers and Coatings

Basic Information

• CAS Number: 77-99-6

• Molecular Formula: C₆H₁₄O₃

• Molecular Weight: 134.17 g/mol

• Appearance: White crystalline solid (typically flakes or granules) at room temperature

• Melting Point: 58–61°C

• Boiling Point: 295°C (decomposes)

• Flash Point: 172°C

• Solubility: Soluble in water, alcohols, ketones, and esters; partially soluble in aromatic hydrocarbons

• Storage: Store in a cool, dry place, in tightly sealed containers, away from moisture and heat

Overview
Trimethylolpropane (TMP) is a trifunctional organic alcohol featuring three primary hydroxyl groups attached to a neopentyl-like backbone. Its molecular structure provides excellent reactivity with acids, isocyanates, and epoxides, making it a versatile building block for the synthesis of branched and crosslinked polymers. TMP is widely used in the production of alkyd resins, polyurethane foams and coatings, polyester resins, and epoxy systems. Its ability to create three-dimensional network structures significantly enhances the mechanical strength, chemical resistance, and thermal stability of finished materials.

Chemical Properties

• Reactivity: Three hydroxyl groups enable controlled branching and crosslinking, improving polymer network density.

• Stability: TMP is chemically stable under normal conditions; however, it readily undergoes esterification, etherification, and urethane formation in the presence of suitable catalysts.

• Hydrophilicity: Moderate water solubility facilitates its use in aqueous and solvent-based systems.

Applications

• Polyurethane foams, coatings, and elastomers: TMP acts as a polyol component, imparting crosslinking density and improving mechanical properties such as tensile strength, hardness, and abrasion resistance.

• Alkyd and polyester resins: Used as a branching agent in paints and varnishes to enhance gloss, adhesion, and weather resistance.

• Epoxy resins: Functions as a chain extender and crosslinker, improving toughness, chemical resistance, and heat distortion temperature.

• Plasticizers and lubricants: Modifies viscosity and flexibility in polymer formulations.

• Specialty monomers: Serves as a precursor for the synthesis of various functionalized derivatives and polymer additives.

Key Benefits

• High reactivity due to three primary hydroxyl groups.

• Improved polymer network density and performance.

• Enhanced mechanical strength, chemical resistance, and thermal stability.

• Versatile compatibility with a wide range of resins, monomers, and catalysts.

• Suitable for solvent-based and high-solids formulations.

• Contributes to environmentally friendly coating systems due to its low volatility.

Safety and Handling

• TMP is generally considered safe for industrial use but may cause mild skin and eye irritation; use appropriate personal protective equipment (gloves, safety goggles) when handling.

• Avoid contact with strong oxidizers and acids.

• Store in a cool, dry place, away from direct sunlight and moisture.

• Shelf life: typically 24 months under recommended storage conditions.

Quality Assurance
Each batch is tested for purity (≥99% typically), hydroxyl value, moisture content, and color to ensure consistent quality for polymer and coating applications.