TDI Toluene Diisocyanate
The aromatic isocyanate behind flexible polyurethane foam
What This Product Is and Who Buys It
TDI is a colourless to pale yellow aromatic diisocyanate with a sharp pungent odour, normally supplied as the 80/20 mixture of the 2,4 and 2,6 isomers. It is highly reactive and is the primary raw material for flexible polyurethane foams, where resilience, comfort and load bearing performance are the deliverables.
Key Benefits
- High reactivity and 48.0 to 48.3 percent NCO content, the most reactive groups per kilogram in our range
- Superior resilience and load bearing capacity in flexible foam
- Established cost position for large volume foam production
- Also serves as a prepolymer feedstock for elastomers adhesives and sealants
Where This Material Is Used
Who It Is For
- Slabstock and moulded foam producers
- Mattress and furniture manufacturers
- Automotive seating suppliers
- Prepolymer and castable elastomer makers
Problems It Solves
- Foam that loses support and resilience over the service life of a mattress or seat
- Large volume foam lines where isocyanate cost per kilogram decides the margin
- Prepolymer systems needing a highly reactive aromatic feedstock
Technical Features
- Colourless to pale yellow clear liquid with a sharp pungent odour
- Molecular formula C9H6N2O2, molecular weight 174.2 g/mol
- Primarily the 80/20 blend of 2,4 and 2,6 isomers
- Freezing point varies with isomer ratio, so storage temperature matters
Specifications
These figures are the manufacturer grade data as published for this product family. Anything not listed below has not been confirmed and is marked TBC on request rather than estimated.
| Property | Specification |
|---|---|
| Appearance | Colourless to pale yellow clear liquid |
| NCO Content (%) | ≈ 48.0 - 48.3 |
| Purity (%) | ≥ 99.5 |
| Boiling Point | ≈ 251°C |
| Freezing Point | ≈ 12 - 21°C depending on isomer ratio |
| Density at 25°C | ≈ 1.21 g/cm³ |
| Molecular Weight | 174.2 g/mol |
Grades listed are representative and not exhaustive. Ask for the batch certificate of analysis on the grade you intend to buy.
How It Compares
Within the Isocyanates category this product is positioned by the numbers in the table above rather than by a marketing claim. Compare NCO content, viscosity, equivalent weight or hydroxyl value against the alternative you are considering, and if the two are close, ask us for both samples and decide on your own line.
Quality and Documentation
Quality control runs across incoming raw materials, production and finished product inspection. A batch certificate of analysis is supplied with every shipment. We are a supply and trading company working with named manufacturers and OEM partners, so certification held by the producing plant is provided on request per grade rather than claimed here as ours.
Customisation
Customised grades and packing formats are available through our OEM partners and specialised manufacturing facilities. Tell us the property you need to move and we will say whether it is a grade change, a packaging change or not possible.
Industries Using This Product
Automotive coatings and interiors are where yellowing resistance, gloss retention and seat comfort are all judged by the end customer rather than by a laboratory.
See Applications
Comfort products are judged by how they feel after three years, not on the day they ship. That is a raw material question about foam resilience and coating durability.
See Applications
TDI Questions
Why does the freezing point range span nine degrees?
Because it depends on the isomer ratio. The 80/20 grade freezes higher than a grade richer in the 2,6 isomer. In a cold warehouse this matters, so confirm the isomer ratio when you order.
Will TDI based foam yellow?
Aromatic isocyanates discolour under UV. In a mattress or a seat cushion the foam is covered, so it is not a problem. In anything exposed to daylight, specify an aliphatic grade instead.
Can TDI be used for coatings?
Yes, through TDI adducts and trimers rather than the monomer. See our TDI Trimer page for the 2K coating hardener grades.
What handling precautions apply?
TDI is a hazardous good with a sharp pungent odour and requires specialised hazard packing, which we prepare as standard for export shipments.
Products Often Bought Alongside This One
Fast curing aromatic hardeners for 2K polyurethane coatings and adhesives
View Specifications
The rigid foam and elastomer workhorse supplied as 4,4'-MDI
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Premium aromatic diisocyanate for high dynamic load elastomers
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Diols triols tetrols and modified grades from 300 to 10000 molecular weight
View SpecificationsRequest a Quote or a Sample of TDI
Samples take about 7 days and are free of charge with shipping at your cost. Production orders ship 20-30 days after the deposit is received.