Architectural dispersity in model branched polymers: Analysis and rheological consequences

We combine state-of-the-art synthetic, chromatographic, rheological, and modeling techniques in order to address the role of architectural polydispersity in the rheology of model branched polymers. This synergy is shown to be imperative in the field and leads to several important results. Even the best available synthesis is prone to "contamination" by side-products. The exact targeted macromolecular structure can be analyzed experimentally and statistically and eventually fractionated. Temperature-gradient interaction chromatography proves to be an indispensible tool in this process. All techniques are sensitive to the various macromolecular structures, but in different ways. In particular, the presence of side-products may or may not influence the linear rheology, due to competing contributions of the different relaxation processes involved, reflecting different structures at different fractions. Hence, combination of all these techniques is the key for fully decoding the architectural composition of branched polymers and its influence on rheology.