One-component adhesive compositions

One-component (1K) adhesive compositions ("PEEP" compositions) and a process for making them are disclosed. A polyepoxide is reacted with a polyether polyol composition, a polyester polyol composition, or both in the presence of a heat-activated Lewis acid catalyst at a temperature within the range of 100° C. to 220° C. for a time effective to cure the adhesive. The compositions are storage-stable under ambient conditions. Compared with conventional epoxy compositions, the 1K PEEP compositions offer improved room temperature lap shear strength, better resilience, and higher elongation. The 1K PEEP systems deliver a desirable balance of physical and mechanical properties while avoiding polyisocyanates and polyamine crosslinkers.