Integration of Diselenide Bonds into Polyurethane Networks: An Impact on Thermomechanical and Solid Polyelectrolyte Properties

Diselenide (Se–Se) bonds were integrated into polyurethane (PU) networks to delve into the impact of dynamic covalent bonds on the comprehensive properties of PU networks including thermal, mechanical, shape memory, and reprocessing properties. First, a PU prepolymer was synthesized through the polyaddition of isophorone diisocyanate with polyethylene glycol. Thereafter, the α,ω-diisocynate-terminated PU prepolymer was cross-linked with two structurally similar tetraols, one of which carries a diselenide bond. It was found that the integration of Se–Se bonds imparted robust mechanical strength to the PU networks. More importantly, the temperature of reprocessing was decreased; that is, the reprocessing properties were significantly improved, with the exchange reaction of Se–Se bonds under mild condition. In terms of the response of shape recovery, fixity, and recovery of shapes, it is judged that the shape memory properties were also significantly improved. Furthermore, the shape memory properties featured reconfigurability under mild conditions. In addition, the reprocessable PUs can further be formulated into the solid polyelectrolytes (SPEs) through the incorporation of lithium bis(trifluoromethanesulphonyl)imide; the ionic conductivity was as high as 3.06 × 10–5 S × cm–1 at 300 K; the ionic transportation was boosted with the integration of Se–Se bonds. Benefiting from the integration of Se–Se bonds, the SPEs were recyclable.