Alternating, aliphatic polyketones were chemically modified by using di-amines to obtain polymeric products having pendant amino groups. The used reaction, Paal-Knorr, involves the formation of pyrrole rings along the polyketone backbone. The corresponding kinetics and final conversions are clearly dependent, among others, on statistical factors (two adjacent carbonyls must react in order to obtain ring formation) as well as on the steric hindrance (sterically hindered amino groups react very slow). The corresponding reaction products (polymeric amines) display very interesting physical properties in aqueous solution. These have been characterized by using dynamic light scattering, Cryo-electron microscopy, fluorescence techniques, etc.