In this work, we synthesized a copolymer of methylmethacrylate with a monomer derived from 2,9-dimethyl-1,10-phenanthroline, in order to be tested for lanthanide uptake and possible nuclear fuel reprocessing. The incorporation of this monomer in the copolymer was confirmed by the observed results on the 1H NMR, which also allowed us to estimate the molar composition of these material. We found that feed composition does not correlate with the composition of the copolymer, which is attributed to a tendency to a preferential incorporation of methylmethacrylate instead the phenanthroline monomer by the growing chain. This behavior would indicate that methylmethacrylate have a higher reactivity, probably attributed to a steric hindrance exerted by the neocuproyl group. The copolymer is stable up to 300 °C. Using ICP we were able to determine that poly(methylmethacrylate-co-N-(2,9-dimethyl-1,10-phenantrolin-5-yl)acrylamide)) shows a marginal retention of rare earth cation at the working low pH, probably due to an unfavorable spatial arrangement of the pendant aromatic groups.