DOSY ¹ H NMR as an Accessible Technique for Characterizing Trends in Bottlebrush Polymer Molecular Weight

Bottlebrush polymers (BBPs) make up a distinctive class of graft copolymers with densely packed side chains, whose unusual macromolecular architecture gives rise to unique physical properties with broad relevance across scientific disciplines. However, their branched architecture challenges traditional molecular weight characterization techniques. Gel permeation chromatography with multiangle light scattering (GPC-MALS) can accurately account for their branching, but this technique is not universally available. Despite its prevalence as a molecular weight determination methodology for linear polymer systems, diffusion-ordered spectroscopy (DOSY) remains underutilized for BBP characterization. Here, we show that DOSY offers an accessible alternative for determining trends in BBP molecular weight, achieving predictive relationships with high linearity (R >0.98) across a breadth of compositions. Additionally, we show that DOSY can provide insights into unique conformational behavior of various BBP compositions through observed scaling relationships, further showcasing the technique’s applicability.