Cardanol-based phenalkamine
Bio-based epoxy hardeners made from cashew nutshell liquid that cure in the cold and the damp, where many amines struggle.
Phenalkamines are Mannich-base curing agents made by reacting cardanol (from cashew nutshell liquid) with formaldehyde and a polyamine. Their structure combines a phenol, amine groups and a long, unsaturated hydrocarbon side chain. Grades vary, so there is no single CAS number.
Phenalkamines cure epoxies for marine and protective primers, tank linings, and work in cold weather or on damp surfaces. They offer low-temperature cure, fast return to service and good water and corrosion resistance.
The phenolic OH accelerates the epoxy–amine reaction, enabling cure near freezing. The long hydrophobic side chain repels water, reducing blush and improving wet adhesion, while adding flexibility. They tend to be darker in color than other hardeners.
Like other amine hardeners, phenalkamines can be corrosive and sensitizing. Wear gloves and eye protection and follow the product SDS.
Partly. The cardanol portion comes from cashew nutshell liquid, a by-product of cashew processing; the amine portion is usually petrochemical.
Their hydrophobic side chains and accelerated cure reduce the time amines spend reacting with carbon dioxide and moisture at the surface.
