Preparation of poly(ionic liquid)/multi-walled carbon nanotube fillers using divinylbenzene as a linker to enhance the impact resistance of polyurethane elastomers

The brittle fracture of polyurethane elastomer (PUE) under high-speed impact limits its application in high-speed impact protection. Here, based on the principle of free radical polymerization and π–π conjugation, composite nanoparticles (C-MWCNTs) are prepared by copolymerization of epoxy group ionic liquid (GVIMBr) and divinylbenzene (DVB) on MWCNTs using DVB as a linker. C-MWCNTs participate in the curing process of PUE through epoxy groups to form in situ crosslinked C-MWCNTs/PUE, which improves the energy absorption and high-speed impact properties of PUE. Compared with neat PUE, the maximum compressive strength and energy absorbed by C-MWCNTs/PUE are increased by 46.3% and 23.6%, respectively. By observing the microsurface and fracture morphology of C-MWCNTs/PUE, the relationship between macroscopic mechanical properties and microstructure is constructed. The improvement of the mechanical properties of the C-MWCNTs/PUE is attributed to the interfacial interaction and homogeneous dispersion of the C-MWCNTs in the PUE matrix. These microscopic effects are caused by the good compatibility between GVIMBr and PUE matrix and the synergistic enhancement between GVIMBr and MWCNTs.