Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a heterocyclic ring containing oxygen (based on polymers of cyclic esters of polyfunctional acids C09J131/00; based on polymers of cyclic anhydrides of unsaturated acids C09J135/00); Adhesives based on derivatives of such polymers