A reactive PSA film that includes: (a) a polymeric film former matrix; (b) one or more reactive components; and (c) a reagent selected from an initiator, a curing agent and an activator. The component (b) is present at a mass fraction of ≥30%, as based on the sum of (a), (b) and (c). Further, ≥50 wt % of the film former matrix is a crystallizable polymer which: (i) exhibits a crystallization enthalpy of