[sbeccaccio]

I am studying blushing phenomena caused by reaction of amine hardeners with atmospheric agents in epoxy systems.
Water and carbon dioxide in certain atmospheric conditions can be combined to produce carbonic acid. The carbonic acid reacts with an amino group of the hardener to produce carbamic acid and water. carbamic acid reacts with another amino group to form carbamate, which gives rise to blushing phenomenon.
I wonder why I get this phenomenon only when I am using imidazole as hardener, and not for example with dicyandiamide.
in the literature I read that amines with lower molecular weight (dicyandiamide about 80g/mol, imidazole about 60g/mol) are more liable to undergo this reaction with carbonic acid. but this explanation does not convince me. who can help me?
I apologize for my English
due attention
best regards