Isophorone diamine
A cycloaliphatic diamine that cures epoxies into clear, hard, chemically resistant films with good color stability. A mainstay of epoxy floor hardeners.
Isophorone diamine (IPDA) is a cycloaliphatic diamine with one amine on the ring and one on a methylene group, the diamine counterpart of IPDI. Its molecular weight is about 170.3 g/mol and it carries four active hydrogens, giving an AHEW of about 42.6 g/eq.
IPDA is widely used in epoxy hardener formulations for floors, self-levelers, coatings and composites, often modified or blended with accelerators (such as benzyl alcohol or phenolic accelerators) to adjust cure speed and reduce blush. It can also act as a chain extender in some polyurea and polyurethane systems.
The rigid ring raises the cured network’s glass transition temperature and hardness. Cycloaliphatic amines give better color stability and chemical resistance than many aliphatic polyamines. With a liquid BPA epoxy (EEW ~188), stoichiometric cure needs about 23 phr of neat IPDA.
IPDA is corrosive to skin and eyes and a skin sensitizer. Wear chemical-resistant gloves and goggles, and wash off any contact immediately.
It gives hard, glossy, chemically resistant films with good clarity and color stability, and blends well with accelerators and other amines.
Less than unmodified aliphatic polyamines, but it can still blush in cold, humid conditions, so formulators often use adducts or accelerators.
