Impact of multi-vinyl taxogen dimensions on high molecular weight soluble polymer synthesis using transfer-dominated branching radical telomerisation

Complex macromolecular architectures offer innovation opportunities through the formation of new polymers with novel physical and chemical behaviour. Optimally existing commercial feedstocks are used as the introduction of new small molecule chemistries may extend regulatory requirements at high expense. In a highly orthogonal synthesis strategy, we recently utilised telomerisation approaches, conventionally targeting small molecule dimerisation, to generate high molecular weight branched polymers. Transfer-dominated Branching Radical Telomerisation (TBRT) employs radical reactions, but yields branched polymers with extended backbones resembling those conventionally formed via step-growth polymerisation. Here we examine the impact of taxogen dimensions on the outcomes of TBRT using multi-vinyl taxogens ethylene glycol dimethacrylate (EGDMA), 1,6-hexanediol dimethacrylate (HDMA) and 1,12-dodecanediol dimethacrylate (LDMA). Marked differences in gelation behaviours were correlated to the dimensions of the taxogen, notably due to the shifting balance of intermolecular and intramolecular branching processes occuring during TBRT.