Assessing the influence of supramolecular crosslinkers within a conjugated polymer network is difficult due to being convoluted by the presence of π-π interactions, the degree of which varies across polymer batches when molecular weight distributions and monomer composition inevitably vary. Here, we implement the strategy of post-polymerization modification to a diketopyrrolopyrrole (DPP) and benzothiadiazole (BT) copolymer, for the attachment of sidechains with tethered hydrogen bonding motifs. By comparison of the parent polymer with its functionalized counterpart, thermal analysis revealed that addition of thymine nucleobases into the material resulted in disrupted ordering in the bulk polymer and in thin films. Grazing incidence wide angle scattering (GIWAXS) patterns were studied in parallel with characterization of organic field effect transistors (OFETs) to correlate changes in microstructural order with charge carrier mobility in as-cast and thermally annealed films. These insights provide a foundation for the rational selection of hydrogen bonding motifs in conjugated polymers and enable the systematic study of functionalized materials for wearable electronic applications.