Which process is moisture-activated and progresses from the exterior toward the interior of the adhesive?

• A. Bond
• B. Caulk
• C. Cross-linked
• D. Conventional Cure (Moisture Cure)

Answer: (D)

Moisture-activated curing means the adhesive hardens when it meets moisture, so the chemical reaction starts at the surface where moisture is immediately available and then travels inward as moisture diffuses through the layer. This exterior-to-interior progression is characteristic of Conventional Cure (Moisture Cure): the moisture in the air or on the substrate initiates the cure at the outer edge, and the cure front moves toward the interior as moisture penetrates deeper. The other terms describe different ideas (bond formation, a generic flexible filler, or a purely cross-linked network) that don’t capture the idea of a moisture-driven cure front moving from outside in.