Despite the ubiquity of branched and network polymers in biological, electronic, and rheological applications, it remains incredibly difficult to predict the network structure arising from polymerization. While modularity and control is afforded in the synthesis of (hyper)branched polymers by Controlled Radical Polymerization techniques, a unifying understanding of network formation providing grounded predictive power is still lacking. A current limitation is the inability to predict whether a crosslink junction will form a functional crosslink or an ineffective loop. Building on a growth boundary analysis, we seek to build intuition on how certain environmental cues affect the crosslink efficiency during network formation, both in the synthesis of (hyper)branched polymers and in gels. With knowledge of an experimental gel point, we demonstrate universal scaling behavior of molecular weights in the synthesis of branched materials that is corroborated by a meta-analysis of literature experiments. We develop an off-lattice monte carlo method which recapitulates the network formation behavior seen experimentally. We further demonstrate a universality in network formation post-gelation in the resulting mechanical properties of the gels. The universality of this analysis offers predictive power for the future synthesis of hyperbranched polymer networks and contiguous gels, affording a synthetic handle to engineer stronger networks from a molecular level.

Universal scaling behaviour during network formation in living polymerizations

2019 Fall National Meeting

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