Segmented Ionenes: Precision within disperse structures yields interesting microstructures and stimuli-responsive behavior

Ionenes are polymers containing a permanent charged group in the polymer backbone and are of interest because of their synthetic versatility, unique morphologies, and ionic nature. The charge placement and the spacing between the charge segments enable the polymer properties to be tuned from glassy solids to rubbery films to viscous liquids. The use of long, soft segment spacers between charges produces a class of polymer called segmented ionenes. When segmented ionenes are prepared with halide counterions (i.e., strong basicity) they form thermoplastic elastomers and microphase separate into microstructures wherein the ionic domains can form a continuous, percolated network at sufficient volume fractions. This talk will discuss recent efforts to utilize the synthetic versatility of this class of polymer to prepare percolated ionic domains in microphase separated polymers that display a range of thermomechanical properties. Furthermore, the combination of synthetic versatility and electrostatic interactions can be used to influence the dispersion of nanoparticles in a segmented ionene matrix as well as influence the nanoparticle solubility in specific microdomains. Finally, the response to external stimulus (e.g., electrical, mechanical) will be discussed and connected to varying chemistries and microstructural features of the polymers.