A polymer including a self-immolative polymer segment and a thermally-activated trigger moiety is described. The self-immolative polymer segment includes a head end, a tail end, and a plurality of repeating units. The trigger moiety includes a cycloaddition adduct that is covalently coupled to the head end of the self-immolative polymer segment. When the polymer is exposed to an activation temperature, the cycloaddition adduct undergoes retro-cycloaddition to release the self-immolative polymer segment. The self-immolative polymer segment then decomposes to sequentially release repeating units in a head-to-tail direction.