Poly[methylene(polyphenyl) isocyanate], also known as pMDI, PMDI, or PAPI, is a polymeric isocyanate used in polyurethane, adhesive, coating, sealant, and composite formulation work. Its isocyanate functionality makes it useful in systems designed to react with compatible hydroxyl-containing materials, polyols, and other formulation components.
Synonyms / related names: PAPI; PMDI; pMDI; polymethylene polyphenyl isocyanate; poly[(phenyl isocyanate)-co-formaldehyde].
This product is supplied as a brown liquid with an isocyanate content specification of 30.20-32.00% by weight. It is commonly selected for laboratory reagent use and manufacture of substances where a polymeric aromatic isocyanate is required for polyurethane or crosslinked polymer systems.
Researchers, formulators, and industrial users may use poly[methylene(polyphenyl) isocyanate] in polyurethane foam development, industrial adhesives, sealants, protective coatings, elastomers, and reinforced composite materials.
Key Properties
- Polymeric aromatic isocyanate
- CAS Number: 9016-87-9
- Product Number: 03099
- Synonyms: PAPI, PMDI, polymethylene polyphenyl isocyanate
- Linear Formula: [-C6H3(NCO)CH2-]n
- Molecular Weight: ~360
- Appearance: Brown liquid
- Isocyanate Content: 30.20-32.00% wt
- Viscosity at 25°C: 150-250 cPs
- Acidity as HCl: ≤0.05%
- Density: 1.24
- Soluble in acetone, THF, and toluene
Applications
Polyurethane Foam Systems
Poly[methylene(polyphenyl) isocyanate] may be used in polyurethane foam formulation work where polymeric isocyanates are selected as reactive components for rigid or flexible foam systems.
Adhesives & Sealants
PMDI is used in adhesive and sealant formulation workflows where isocyanate reactivity, crosslinking behavior, bond performance, and chemical resistance are important considerations.
Protective Coatings
This product may be used in coating formulation work involving polyurethane or isocyanate-reactive systems where durability and cured-film performance are evaluated.
Composite Materials
Polymeric isocyanates such as PMDI may be used in reinforced plastics and composite-related formulations where matrix chemistry, filler compatibility, and cured mechanical properties are controlled through formulation design.
Compatibility & Formulation Considerations
- Reactive isocyanate functionality should be used with compatible formulation components
- Commonly evaluated with polyols and other active-hydrogen-containing materials in polyurethane systems
- Final performance depends on stoichiometry, catalyst package, moisture control, temperature, processing method, and cure schedule
- Solvent and additive compatibility should be confirmed before scale-up
Application suitability should be verified under the user’s specific formulation, processing, substrate, and end-use conditions.
Preparation Tips
- Use clean, dry equipment when handling isocyanate-reactive formulations
- Control moisture exposure during formulation and storage
- Measure reactive components carefully according to the selected formulation
- Mix thoroughly to support uniform reaction and consistent final properties
- Run small-scale trials before production or process transfer
Handling & Storage
- Store at room temperature
- Store in a well-ventilated place and keep cool
- Use gloves and a fume hood
- Use only outdoors or in a well-ventilated area
- Avoid breathing dust, fume, gas, mist, vapors, or spray
- Avoid contact with skin and eyes
- Refer to the Safety Data Sheet before handling
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FAQ
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1. What is Poly[methylene(polyphenyl) isocyanate] used for?
Poly[methylene(polyphenyl) isocyanate] is used in polyurethane foam formulation, adhesives, sealants, protective coatings, composite materials, and related isocyanate-reactive polymer systems.
2. What is the isocyanate content of this product?
The product specification lists isocyanate content at 30.20-32.00% by weight.
3. What are common synonyms for this product?
Common synonyms include PAPI, PMDI, pMDI, polymethylene polyphenyl isocyanate, and poly[(phenyl isocyanate)-co-formaldehyde].
4. What solvents dissolve Poly[methylene(polyphenyl) isocyanate]?
The product page lists solubility in acetone, THF, and toluene.
5. How should Poly[methylene(polyphenyl) isocyanate] be stored?
Store the product at room temperature in a well-ventilated place and keep cool. Review the Safety Data Sheet for complete storage, handling, and personal protective equipment guidance.
Safety & Documentation
Poly[methylene(polyphenyl) isocyanate] should be handled using gloves, eye protection, good ventilation, and a fume hood. The product is classified as harmful if inhaled and may cause skin and eye irritation. Avoid breathing dust, fume, gas, mist, vapors, or spray, and avoid contact with skin and eyes. Refer to the Safety Data Sheet (SDS) and product specification for complete handling, storage, hazard, and technical information.
