Diphenylphosphino Styrene‐Containing Homopolymers: Influence of Alkylation and Mobile Anions on Physical Properties

Abstract

Conventional free radical polymerization and post-alkylation of 4-diphenylphosphino styrene (DPPS) generate a new class of high-molecular-weight phosphonium-containing homopolymers with tunable thermal, viscoelastic, and wetting properties. Post-alkylation and subsequent anion exchange provide an effective method for tuning Tg values and thermal stability as a function of alkyl chain length and counteranion selection (X(-) , BF4 (-) , TfO(-) , and Tf2 N(-) ). Rheological characterization facilitates the generation of time-temperature-superposition (TTS) pseudomaster curves and subsequent analysis of frequency sweeps at various temperatures reveals two relaxation modes corresponding to long-range segmental motion and the onset of viscous flow. Contact angle measurements reveal the influence of counteranion selection on wetting properties, revealing increased contact angles for homopolymers containing nucleophilic counteranions. These investigations provide fundamental insight into phosphonium-containing polymers, aiming to guide future research and applications involving electro-active polymeric devices.

Polymerized ionic liquids: Effects of counter‐anions on ion conduction and polymerization kinetics

“…S4, Supporting Information) yielded 5 wt% degradation temperatures (T d,5% ) of 372, 325, 300, and 249 °C for poly(1BDIMATf 2 N), poly(1BDIMABF 4 ), poly(1BDIMAPF 6 ), and poly(1BDIMABr), respectively (Table ). As expected, the less nucleophilic and less basic counter‐ions had higher degradation temperatures . Only 1BDIMABr demonstrated an obvious water weight loss (∼ 2 wt%) during the 120 °C isotherm step, as the other three ion pairs were hydrophobic.…”

“…The counter‐ion effect on the physical properties of PILs is a well‐known phenomenon . However, to compare the thermal properties and ion conductivity performance of PILs with four different counter‐ions, the molecular weight should ideally be similar.…”

“…Additionally, PILs with PF 6 counter‐ions showed lower ion conductivity than Tf 2 N due to differences in polymer chain mobility arising from the variation in T g s and ion association differences derived from specific molecular interactions . Jangu et al also reported the T g and effects of counter‐ion identity in styrenic PILs . Those findings showed that T g s decreased in the order: Br > BF 4 > TfO (trifluoromethanesulfonate) > Tf 2 N, probably due to counter‐ion size effects and weakened Columbic interactions, while thermal degradation exhibited the reverse order.…”

Phosphonium polymers for gene delivery

“…Phosphonium salts and their corresponding polymers have been investigated in a range of applications which span from ion exchange membranes 18,31 and selectively permeable membranes, 32 treatment of drinking water, 33 to cationic biocides, [34][35][36][37] cell-penetrating agents, 38 and ionomers. 39,40 Various polymerisation and post-polymerisation approaches have been utilised to generate phosphonium-containing polymers, however only relatively recently phosphonium polymers have been exploited as biological active polymers with antimicrobial properties [34][35][36][37][41][42][43][44] and for the delivery of nucleic acid 21,23,30 .…”

“…18,19 To date only a relatively small number of studies successfully implemented phosphonium-based polymers for gene delivery. 20 This review will provide a comprehensive overview of the state of the art of the field.…”