How can I get faster cure at low temperatures in my epoxy coating system?
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||David Dubowik |
Principal Applications Chemist
Low-temperature cure depends on proper curing agent, accelerator, and epoxy diluent selection. Therefore, consider the following:
- Select a low-blush curing agent with good low-temperature reactivity. Curing agents, such as Ancamine® 2143, 1856, 2432 and 2089M, have very accessible amine groups and make it easier for epoxies to react with at low temperatures. Avoid high-blush amines and slow reacting amines, such as amidoamines and polyamides.
- Accelerators, such as Ancamine K.54, when used at moderate levels (5 phr), will improve dry time and hardness development without compromising properties.
- Systems with lower glass transition temperatures (Tg) react more completely than systems with higher Tgs. Epoxy diluents will lower the Tg and allow the system to cure before it loses mobility. Diluents, such as Epodil® 742, 749 and 750, are preferred due to their fast reactivity. Because diluents reduce physical strength properties, they should be used judiciously.