Incorporation of supramolecular cross-linking motifs into low-ceiling temperature (Tc) polymers allows for the possibility of remendable polymeric networks and nanoparticles whose structure and chemical backbones can be dynamically modified or depolymerized as desired. Herein, we demonstrate the synthesis of phthalaldehyde-benzaldehyde copolymers bearing a pendant dimerizing 2-ureido-pyrimidinone (UPy) motif. The UPy moiety promotes single-chain polymeric nanoparticle formation through non-covalent cross-linking at intermediate concentrations and results in reversible polymer network formation at high concentrations. Furthermore, due to the low Tc polymer backbone within such macromolecules, the materials depolymerize to monomer under appropriate conditions. We envision that the synthesis of such depolymerizable, adaptive supramolecular polymeric materials may find use in materials capable of self-healing and remodeling as well as in triggered release applications or the development of nanoporous structures.