This is a substance added to an adhesive to promote the curing reaction by
taking part through catalysis or cross-linking. Two-part adhesive systems
generally have one part that is the base and a second part that is the hardener
. Upon mixing, a chemical reaction takes place that causes the adhesive
to solidify. A catalyst is sometimes incorporated in an adhesive formulation
to speed up the reaction between the base and the hardener. Very small
amounts of catalyst are required, compared to the principal components
such as base and hardener.