Isophorone Diamine (IPDA)

Isophorone Diamine (IPDA) is a cycloaliphatic diamine with a rigid ring structure that imparts exceptional UV stability, outstanding color retention, and high glass transition temperatures to epoxy cured systems. Unlike aliphatic polyamines (DETA, TETA), IPDA-cured epoxies resist yellowing under UV and light exposure, making them ideal for outdoor, marine, and architectural applications where long-term aesthetics are critical. IPDA provides a moderate cure speed with pot lives of 60–120 minutes for standard 100g epoxy batches at 25°C. Its amine hydrogen equivalent weight (AHEW) is approximately 42.6 g/eq. The stoichiometric dosage is approximately 22–24 phr for standard BPA epoxy. The cycloaliphatic structure gives cured systems exceptional electrical insulation properties, low water absorption, and good mechanical performance up to 120–130°C (with post-cure). IPDA is extensively used in UV-resistant marine varnishes and topcoats, clear floor coatings, composite sporting goods, wind turbine blade coatings, and aerospace epoxy laminates where Tg and optical clarity matter.