Overview
Isophorone Diisocyanate (IPDI) is an aliphatic diisocyanate derived from isophorone, widely used in polyurethane formulations. Its cyclic structure provides exceptional weathering resistance, making it ideal for outdoor applications. Unlike aromatic diisocyanates, IPDI does not yellow under UV exposure, which is critical for coatings in automotive and architectural sectors. IPDI's slow reactivity allows for better processing control in adhesives and elastomers. It is commercially available as a monomer or pre-polymer, with purity levels ranging from 98% to 99.5%. The compound is classified as hazardous due to its isocyanate groups, requiring strict handling protocols.
Physical and Chemical Properties
IPDI is a colorless to slightly yellow liquid with a mild odor. It has a low viscosity (approximately 15 mPa·s at 25°C), facilitating easy mixing in formulations. The compound's boiling point at reduced pressure (158°C at 10 mmHg) ensures stability during processing. Chemically, IPDI reacts with hydroxyl groups to form urethane linkages, the basis of polyurethane synthesis. It is hydrolyzed by water, releasing CO2 and amines, which necessitates moisture-free storage. Its aliphatic nature grants resistance to oxidation and UV degradation, outperforming aromatic counterparts like TDI or MDI in durability.
Main Applications
IPDI is a cornerstone in high-performance polyurethane coatings, especially for automotive clear coats and aircraft finishes. Its UV stability prevents yellowing, while its adhesion properties enhance substrate compatibility. In adhesives, IPDI-based formulations offer flexibility and chemical resistance, suitable for bonding plastics and metals. The elastomers derived from IPDI are used in seals, gaskets, and medical devices due to their biocompatibility and mechanical strength. Industrial applications include corrosion-resistant tank linings and weatherproof architectural coatings. Niche uses encompass light-stable inks and synthetic leather production.
Safety and Storage
IPDI is classified as a hazardous substance (H318, H334) and requires stringent safety measures. Inhalation of vapors can cause respiratory sensitization, while skin contact leads to irritation or allergic reactions. Always use fume hoods, nitrile gloves, and sealed containers during handling. Storage must avoid moisture and high temperatures to prevent polymerization. Drums should be nitrogen-purged and kept away from acids, alcohols, or amines. Spills must be neutralized with specialized isocyanate destroyers, not water. Disposal must comply with local regulations for hazardous waste.
B2B Procurement Guide
When sourcing IPDI, verify the supplier's CAS number (4098-71-9) and request a Safety Data Sheet (SDS). Reputable manufacturers provide batch-specific certificates of analysis (CoA) detailing purity, NCO content, and viscosity. Bulk purchases (drums or IBCs) typically offer cost savings of 10–15% over small quantities. Logistics should ensure temperature-controlled transport to prevent crystallization or moisture ingress. For pre-polymers, confirm the equivalent weight and functionality to match application needs. Alternative aliphatic diisocyanates like HDI or H12MDI may be considered for specific performance requirements.