Organic peroxide vulcanization of <scp>PDMS</scp> nanocomposites obtained with the reactive carbon nanofiller: (4‐vinylbenzyl) aziridine‐<scp>SWCNT</scp>

Abstract Surface functionalized single‐walled carbon nanotubes (SWCNT) with 4‐(azidomethyl) styrene were prepared through [2 + 1] nitrene cycloaddition reaction. 53 molecules of (4‐vinylbenzyl) per 1000 carbon atoms were obtained. Sidewall covalent functionalization was confirmed by spectroscopic techniques (FTIR, Raman, and XPS) and TGA. According to Raman and XRD spectroscopy, the integrity of the CNT was preserved, suggesting that the aziridine rings help to restore the aromaticity over the CNT structural defects. The reactive styrene moiety on (4‐vinylbenzyl) aziridine‐SWCNT was reacted with PDMS during the cross‐linking process with vinyl or aryl peroxides (dicumyl peroxide (DCP), (T29) or (T145) from Akzo Nobel Chemicals). Testing specimens of composites integrated by 0.7 grams of (4‐vinylbenzyl) aziridine‐SWCNT per one hundred grams of PDMS were obtained according to ASTM D‐624 standard method after its processing in an open roller mill followed by compression molding. When compared to the PDMS vulcanization, up to 35% reductions in vulcanization time ( v.t .) were observed with the use of (4‐vinylbenzyl) aziridine‐SWCNT as a reactive filler. Improvements in their mechanical properties, up to 75% of tensile strength, 85% elastic limit, 40% in tear strength, and 35% in Shore A hardness were observed when PDC was used and compared with neat PDMS vulcanized with the same crosslinking agent. Among all the (4‐vinylbenzyl) aziridine‐SWCNT‐PDMS composites formulated, those obtained with T145 or DCP (2.5 phr) exhibited the highest level of improvement in both v.t . and physics‐mechanical properties. These findings open new opportunities to apply carbon nanostructures as a reactive filler in the construction of conductive or piezoresistive flexible stretchable devices. Highlights PDMS OP vulcanization with reactive (4‐vinylbenzyl) aziridine‐SWCNT. Sidewall functionalization of SWCNT with (4‐azidomethyl) styrene. SWCNT sidewall functionalization through [2 + 1] nitrene cycloaddition. Fully spectroscopic characterization of (4‐vinylbenzyl) aziridine‐SWCNT. Significant mechanical performance improvements with PDMS‐SWCNT nanocomposites.