MDI (4,4′-diphenylmethane diisocyanate) is a high-purity aromatic isocyanate — the key reactive component (the “B / black material”) that reacts with polyols to build polyurethane. With purity ≥ 99.5% and NCO ≥ 31.8%, this refined MDI delivers excellent mechanical strength, durability and chemical stability for PU elastomers, TPU, microcellular foams, adhesives and coatings. Low chlorine and low colour for consistent, high-performance systems.
≥ 99.5%
purity (GC)
≥ 31.8%
NCO content
≤ 30
Colour (Pt–Co)
~30
Viscosity mPa·s (25 °C)
< 10
hydrolysable Cl ppm
Key Features
High purity & NCO ≥ 99.5% purity and ≥ 31.8% NCO for strong, consistent crosslinking.
Excellent mechanical strength Produces tough, durable PU elastomers and TPU with high tensile and tear.
Low chlorine & colour Hydrolysable Cl < 10 ppm and colour ≤ 30 for clean, stable reactions.
Low viscosity ~30 mPa·s for easy metering and mixing with polyols.
Versatile building block The MDI component for elastomers, TPU, adhesives, coatings and foams.
Reliable supply Consistent batches with COA, packed and palletised for export.
Used to produce: PU & TPU elastomers, microcellular & integral-skin foams, structural adhesives and sealants, PU coatings and dispersions, and as the MDI reactive component in two-component PU systems.
Technical Specifications
Item
Specification
Standard
Purity
≥ 99.5%
GC
NCO content
≥ 31.8%
GB 12009.4
Colour (Platinum–Cobalt)
≤ 30
GB 3143
Freezing point
≤ 25 °C
GB 7533
Density (20 °C)
~ 1.07 g/cm³
GB 4472
Flash point
~ 210 °C
GB/T 261
Viscosity (25 °C)
~ 30 mPa·s
GB 12009.3
Hydrolysable chlorine
< 10 ppm
Internal
Total chlorine
≤ 1000 ppm
Internal
Typical values for reference, not a binding specification. Full TDS & MSDS on request.
MDI vs. HDI
MDI (this product) — aromatic High reactivity and strength for elastomers, TPU, foams and adhesives. Cost-effective workhorse isocyanate.
HDI — aliphatic Non-yellowing, for UV-stable clear-coats and paints — see our HDI isocyanate.
Packaging, Storage & Handling
Packaging Supplied in sealed steel drums; palletised for export. Bulk on request.
Storage Keep containers tightly sealed and dry — MDI reacts with moisture and can freeze below 25 °C (re-melt gently and mix before use). Store cool, indoors.
Handling & Safety Use with adequate ventilation and PPE; avoid eye/skin contact and vapour. Full MSDS on request.
10+ years in PU raw materials Specialised blended-polyol, isocyanate & PU systems supplier worldwide.
Consistent quality High purity, low chlorine and low colour, batch-to-batch.
One-stop polyol + isocyanate Matched polyols and systems for complete PU formulations.
Global export & fast reply Export to EU, Latin America, Asia and beyond — we respond within 24 hours.
From Sample to Bulk Order
1. Share your system Tell us the PU application and polyol — we confirm the MDI grade and ratio.
2. Sample & validate Trial batches with TDS, MSDS and COA for your tests.
3. Scale to bulk Confirm the grade and order in bulk with flexible MOQ and tiered lead times.
Frequently Asked Questions
Is this pure MDI or polymeric MDI?This is high-purity 4,4′-MDI (purity ≥ 99.5%, NCO ≥ 31.8%) for elastomers, TPU, microcellular foams, adhesives and coatings — tell us your application and we confirm the right grade.
Why does MDI freeze?Pure MDI solidifies below ~25 °C. Re-melt gently (warm, sealed) and mix thoroughly before use; avoid moisture during handling.
MDI or HDI for my product?MDI (aromatic) for strength and cost in elastomers, foams and adhesives; HDI (aliphatic) for non-yellowing clear-coats and paints.
Do you provide documentation?Yes — TDS, MSDS and per-batch COA; request a sample and we reply within 24 hours.
Need MDI isocyanate for your PU system?
Get grade confirmation, full TDS & MSDS, and a sample — with matched polyols if you need them.
✓ Purity ≥ 99.5%✓ TDS · MSDS · COA✓ Reply within 24 h
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