Name: IPDI Monomer for PU Adhesives
Brand: Coatingsink
SKU: ipdi-isocyanate-pu-adhesive
Availability: InStock

Question 1

Why is IPDI preferred over MDI or TDI for light-stable polyurethane adhesives?

Accepted Answer

IPDI is an aliphatic diisocyanate; its NCO groups are not conjugated to an aromatic ring, so photo-oxidative yellowing does not occur. MDI and TDI are aromatic isocyanates that form quinone-imine chromophores under UV exposure, causing rapid discoloration. IPDI-based polyurethanes retain color, gloss, and mechanical integrity in outdoor and high-UV environments, making them standard for automotive OEM clear coats, optical laminating adhesives, and exterior wood finishes.

Question 2

How is IPDI monomer used to prepare an NCO-terminated prepolymer for 2K adhesives?

Accepted Answer

IPDI is reacted with a dried polyol (polyether or polyester diol, OH value 30–100 mg KOH/g) at an NCO/OH ratio of 2:1 at 60–80°C with a tin or bismuth catalyst until the theoretical NCO content is reached (verified by titration per ASTM D2572). The resulting prepolymer carries 3–8% residual NCO. Free monomer content is minimized by controlling stoichiometry precisely; Part B chain extenders (polyamines or polyols) crosslink the system at ambient temperature.

Question 3

What are the key storage and handling requirements for IPDI monomer?

Accepted Answer

IPDI is a respiratory sensitizer; handle under local exhaust ventilation with a P100/OV respirator, nitrile gloves, and splash goggles. Store sealed under dry nitrogen at 10–25°C—moisture ingestion causes CO₂ generation, viscosity rise, and formation of insoluble urea particles. Shelf life is 12 months from manufacture in original sealed drums. Contaminated material must be deactivated with excess water or amine before disposal per local isocyanate waste regulations.

NCO Content	37.8%
Monomer Purity	≥99.5%
Density (25°C)	1.06 g/ml
Viscosity (25°C)	8–12 mPa·s
NCO Equivalent Weight	111 g/mol

IPDI Monomer for PU Adhesives

Specifications

FAQ

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