Trimethylolpropane (TMP) is a triol, meaning it contains three hydroxyl (-OH) groups.
This makes it highly reactive and valuable in applications requiring crosslinking, such as in the manufacture of alkyd resins, polyurethanes, and synthetic lubricants.
TMP has a branched structure and offers excellent resistance to degradation, heat, and chemicals when incorporated into polymers.
CAS Number
77-99-6
Synonyms
TMP,1,1,1-Trimethylolpropane,Tris(hydroxymethyl)propane,2-Ethyl-2-(hydroxymethyl)-1,3-propanediol,Trimethyl propane
Introduction
Trimethylolpropane (TMP), a triol compound with the molecular formula C6H14O3, is a versatile organic molecule widely employed across various industrial sectors.
It contains three hydroxyl groups, making it highly functional for numerous chemical reactions and ideal for synthesizing complex molecules.
Since its initial synthesis in the early 20th century, TMP has become a crucial component in the production of polyesters, alkyd resins, polyurethanes, and lubricants.
This document presents an exhaustive analysis of TMP, delving into its chemical characteristics, synthesis, applications, and environmental implications.
Chemical Structure and Properties
TMP, or 2-ethyl-2-(hydroxymethyl)-1,3-propanediol, is characterized by a central quaternary carbon atom bonded to three hydroxymethyl groups and an ethyl group.
This structure imparts high thermal stability and multifunctionality.
Molecular weight: 134.17 g/mol
Melting point: 58°C
Boiling point: 295°C (decomposes)
Solubility: Miscible with water and polar organic solvents
Reactivity: The three hydroxyl groups enable esterification, etherification, and urethane formation.
Spectroscopic Data:
NMR: Shows characteristic proton shifts for hydroxyl (-OH) and methylene (-CH2-) protons.
IR: Strong absorption bands around 3300 cm^-1 (O-H stretch) and 1040 cm^-1 (C-O stretch).
MS: Molecular ion peak at m/z = 134.
Synthesis of Trimethylolpropane
Industrial synthesis of TMP involves a two-step reaction. Initially, butyraldehyde undergoes an aldol condensation with formaldehyde, producing an intermediate.
This is followed by hydrogenation:
Step 1: Butyraldehyde + 2 HCHO → 2-ethyl-2-hydroxymethyl-3-hydroxypropanal
Step 2: Hydrogenation over a catalyst (e.g., Ni or Cu/Cr) yields TMP.
Critical parameters include temperature (80–100°C), pressure (3–10 MPa), and catalyst selection, affecting yield and purity.
Alternative green methods using biocatalysts and continuous flow reactors are under investigation.
Applications
TMP is an indispensable intermediate in numerous formulations:
Alkyd resins: Used in paints and varnishes due to excellent film-forming properties.
Polyester polyols: Precursor for flexible and rigid polyurethane foams.
Lubricants: TMP esters improve thermal stability and biodegradability.
Adhesives & sealants: Contributes to crosslinking density and mechanical strength.
Radiation-curable resins: TMP triacrylate is used in UV/EB curing systems.
Plasticizers and surfactants: TMP serves as a building block for specialty esters.
Derivatives and Chemical Modifications
TMP's hydroxyl groups allow for a range of derivatizations:
TMP esters: Synthesized via esterification with fatty acids; used in lubricants.
TMP ethers: Formed by etherification with alkyl halides or epoxides.
Acrylated TMP: Used in radiation-cured coatings and 3D printing materials.
TMP carbonate and urethanes: For producing flexible polyurethanes and thermoplastic elastomers.
Benefits and Limitations
Advantages:
High reactivity due to three hydroxyl groups
Structural rigidity contributes to durable end-products
Excellent thermal and chemical resistance
Good solubility profile
Limitations:
Requires careful handling due to hygroscopic nature
Decomposes upon overheating
Potential for crosslinking imbalance in formulations
SAFETY INFORMATION ABOUT TRIMETHYLOLPROPANE (TMP)
First aid measures:
Description of first aid measures:
General advice:
Consult a physician.
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
If inhaled:
If breathed in, move person into fresh air.
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately.
Wash off with soap and plenty of water.
Consult a physician.
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
If swallowed:
Do NOT induce vomiting.
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
Consult a physician.
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment.
Avoid breathing vapours, mist or gas.
Evacuate personnel to safe areas.
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste.
Keep in suitable, closed containers for disposal.
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place.
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles.
Faceshield (8-inch minimum).
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Skin protection:
Handle with gloves.
Gloves must be inspected prior to use.
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product.
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices.
Wash and dry hands.
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls.
If the respirator is the sole means of protection, use a full-face supplied air respirator.
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions.
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company.
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product