- ▸ Rigid aromatic diisocyanate used to make high-performance polyurethane elastomers with excellent thermal and dynamic properties
- ▸ Crosslinks polyols/polyamines into PU prepolymers for demanding elastomer and roll-cover applications
- ▸ Delivers high hardness, heat resistance and load-bearing performance in cast PU
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
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para-Phenylene diisocyanate (PPDI) is a high-performance aromatic diisocyanate — its rigid, symmetric structure gives polyurethane elastomers with outstanding dynamic, thermal and hydrolytic performance. Identity: CAS 104-49-4.
What it is
para-Phenylene diisocyanate (CAS 104-49-4) is a crystalline aromatic diisocyanate. Its short, rigid, symmetric structure produces highly ordered hard segments in PU elastomers.
How it works
Its NCO groups react with polyols to form PU; the rigid PPDI hard segment gives elastomers with exceptional dynamic (flex-fatigue), heat and hydrolysis resistance — a premium choice for demanding cast elastomers.
Applications
PPDI is used in high-performance cast polyurethane elastomers (rolls, wheels, dynamic parts) where heat and flex-fatigue resistance are critical. Compare aliphatic TMDI.
Forms, grades and handling
PPDI is supplied as a solid/molten grade in moisture-protected packaging. Properties are typical reference values; the Certificate of Analysis (CoA) for the lot you buy governs. Isocyanates are moisture-sensitive and require respiratory/skin precautions; handle per the current Safety Data Sheet (SDS). Each lot ships with CoA, TDS and SDS.
Bulk supply and RFQ
RawSource sources para-Phenylene Diisocyanate direct from producers in bulk, with CoA, TDS and SDS per lot. Tell us your binder system, cure schedule and the performance you need, and we will quote the right grade. See the polyurethane catalysts guide for the catalysts that drive these reactions.
Typical Properties
Typical reference values, not a specification; the Certificate of Analysis (CoA) for the lot governs.
| Property | Typical Value |
|---|---|
| Chemical / class | Aromatic diisocyanate (PPDI) |
| Function | High-performance PU building block |
| CAS Number | 104-49-4 |
| Molecular Formula | C8H4N2O2 |
| Molecular Weight | 160.13 g/mol |
| Handling | Refer to the current SDS |
Regulatory & registration requirements
- TSCA (US):
- REACH (EU):
- EC number: 203-207-6
Source: EPA TSCA Inventory (July 2025 release) · ECHA CHEM — retrieved 2026-07-12
Frequently Asked Questions
What is para-phenylene diisocyanate (PPDI) used for?
PPDI (CAS 104-49-4) is a high-performance aromatic diisocyanate for premium cast polyurethane elastomers (rolls, wheels, dynamic parts), giving outstanding dynamic, thermal and hydrolytic resistance.
How is bulk PPDI supplied and quoted?
RawSource supplies PPDI in bulk with CoA, TDS and SDS per lot. Pricing is quote-based on grade and volume; submit an RFQ with your binder system and cure schedule.
What is the REACH and TSCA regulatory status of para-Phenylene Diisocyanate (PPDI)?
para-Phenylene Diisocyanate (PPDI) (CAS 104-49-4) is subject to U.S. TSCA Inventory requirements; supplying it into the EU requires valid REACH registration ((EC) No 1907/2006). RawSource cannot verify a third-party supplier's registrations — buyers should require documented TSCA and REACH compliance for their jurisdiction and volume (EC 203-207-6).