A process is described for treating metal surfaces with roughening compositions that use poly(ethyleneamino propionitrile) polymer as an additive in the composition to improve adhesion of polymeric materials to the metal surfaces and to improve peel strength for thermal stability. The polymer of the invention may be added to compositions containing for example, cupric chloride and hydrochloric acid and is also usable in compositions containing an oxidizer/acid/azole mixture. Other additives, such as adiponitrile may also be beneficially added to compositions of the invention.