Polyelectrolytes provide a library of unique properties that lead to applications ranging from battery membranes and electrolytes, gas purification to stimuli-responsive materials. Despite the extensive studies on polyelectrolytes, the influence of ionic interactions on the polymerization kinetics is less understood, especially in controlled radical polymerization (CRP). We successfully synthesized four imidazolium-containing ionic-liquid monomers with identical chemical structures except counter ions. I<i>n-situ</i> FTIR monitored the corresponding polymerization kinetics of four different ionic-liquid monomers in both conventional free radical polymerization and reversible addition-fragmentation chain-transfer polymerization (RAFT). The counter ions demonstrated minimum influence on the kinetics of conventional radical polymerization, but showed drastic polymerization rate difference in RAFT polymerization. RAFT polymerization of the same ionic-liquid monomer in different solvents also revealed kinetic differences, suggesting a relationship between ion aggregation and polymerization kinetics. DLS further proved the existence of ion aggregation and different diffusivity dependent on counter ions. As a result of, the ionic interaction presented a significant influence on CRP, while free radical polymerization diminished its effect through fast and uncontrolled monomer propagation.

Counter-ion effect on radical polymerization kinetics of ionic-liquid monomers

254th National Meeting (2017)

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