Description

Polymethylene Polyphenyl Polyisocyanate (PAPI) is a polymeric isocyanate and a core component in the production of high-performance polyurethane materials. This compound is critical for creating rigid foams, adhesives, and coatings with exceptional thermal stability, mechanical strength, and chemical resistance. It is essential for manufacturers in the construction, automotive, and appliance industries seeking durable, lightweight, and insulating materials.

Application

• Rigid Polyurethane Foam: Primary raw material for insulation panels, spray foams, and appliance foams (refrigerators, water heaters).
• Coatings & Adhesives: Used in high-performance industrial coatings, waterproof membranes, and structural adhesives.
• Elastomers & Binders: Key component in the manufacture of polyurethane elastomers for wheels, rollers, and as a binder for foundry sands.
• Construction Materials: Integral to composite wood products (OSB, particleboard) and sealants for enhanced durability and moisture resistance.

Basic Information

Product Name	Polymethylene Polyphenyl Polyisocyanate
CAS No.	9016-87-9
Molecular Formula	Mixture (C15H10N2O2)n
Molecular Weight	~300-400 (Average)
Synonyms	Polymeric MDI; PMPPI; PAPI; Crude MDI; Diphenylmethane diisocyanate, polymeric; Polymethylene polyphenylene isocyanate; 4,4'-Methylenediphenyl diisocyanate, homopolymer; Isocyanic acid, polymethylenepolyphenylene ester
EINECS	Contact for details

Quality Control

Our Polymethylene Polyphenyl Polyisocyanate is manufactured under strict process controls to ensure batch-to-batch consistency and performance. Quality is verified through parameters including NCO content, viscosity, acidity, and hydrolyzable chlorine. A Certificate of Analysis (COA) documenting these specifications is provided with every shipment to guarantee compliance with your formulation requirements.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at temperatures between 15-25°C (59-77°F). This product is hygroscopic (moisture-sensitive). Keep containers tightly sealed to prevent contact with atmospheric moisture, which can cause polymerization or gelation. Isolate from strong bases, amines, alcohols, and water.

Specification

Item	Specification
Appearance	Brown, viscous liquid
NCO Content	30.0 - 32.0 %
Viscosity (25°C)	150 - 250 mPa·s
Acidity (as HCl)	≤ 0.05 %
Hydrolyzable Chlorine	≤ 0.2 %
Specific Gravity (25°C)	~1.23

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.