Epoxy adhesives are generally more resistant to a wide variety of liquid environments than other structural adhesives. The polymercaptans can also be used to accelerate the curing of epoxy resins systems blended with polyamines, amidoamines, or amines. The other curatives serve as the base to accelerate mercaptans, and the mercaptans react rapidly, generating the heat to accelerate the cure with the other hardener. The major disadvantages of mercaptan curing agents are their odor, skinning, and low heat deflection temperature.
RESULTING PROPERTIES
Typical starting formulations for rapid setting, room temperature curing epoxy mercaptan adhesive formulations are shown in the above table. The reaction of these materials when used alone is very sluggish at room temperature. However, the reaction proceeds at a practical rate by the addition of a base, which acts as an accelerator. Tertiary amines, such as DMP-10 or 30; triethylene tetramine (TETA), and diethylene triamine (DETA) are commonly used for this application.
