Developing highly conducting and mechanically durable styrene butadiene rubber composites with tailored microstructural properties by a green approach using ionic liquid modified MWCNTs

Abstract

We report the effect of surface modification of multi-walled carbon nanotubes (MWCNTs) by an ionic liquid, 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl). An apparent physical (cation-p/p-p) interaction between the ionic liquid and MWCNTs was revealed by Raman and UV-visible spectroscopies. The composite loaded with 10 phr MWCNTs exhibits impressive enhancements in tensile strength (381% increase), hardness (34% increase), and abrasion resistance. High electrical conductivity was also achieved at MWCNT loading levels beyond 3 phr loading, with a low percolation threshold (0.023 vol%) for the composites. The microstructural development of conductive networks and uniform dispersion of MWCNTs in the presence of ionic liquid were analysed by TEM and AFM. The experimentally observed mechanical and electrical properties have been compared with theoretical predictions, and confirm that the dramatic improvement in mechanics and electrical conductivity is the outcome of the extremely fine dispersion, the strong secondary network of MWCNTs and improved interaction at the interface via thermodynamically-induced adsorption and physical interlocking of polymer chains in the nanoscopic MWCNT structure. This study demonstrates a simplified and ecofriendly approach to develop multifunctional advanced materials based on ionic liquid modified MWCNT elastomer composites with a much better balance among mechanical properties, conductivity and filler content.

Conducting melt blending of polystyrene and EVA copolymer with carbon nanotube assisted by phosphonium‐based ionic liquid

“…Figure compares the TEM images of PS/EVA blends with 1.0% of n‐CNT and IL‐CNT. The noncovalent functionalization of CNT by the IL results in a better dispersion of CNT [Figure (d)], as also observed in other binary systems, such as SBR/CNT or PS/CNT composites.…”

“…They belong to a salt family constituted by large asymmetrical organic cation and organic or inorganic anion and presents unique properties such as low vapor pressure, good ionic conductivity, thermal stability, and low melting temperature (below 100 °C). Several systems involving thermoplastic, rubber, and thermosetting matrices containing CNT were investigated, thus showing outstanding electrical conductivity and decreased percolation threshold in the presence of ILs due to the better CNT dispersion. However, few studies in this field have been addressed to the use of heterogeneous polymer blend as the matrix.…”

Morphological, dielectric, tunable electromagnetic interference shielding and thermal characteristics of multiwalled carbon nanotube incorporated polymer nanocomposites: A facile, environmentally benign and cost effective approach realized via polymer latex/waterborne polymer as matrix

“…followed by sonication to disperse and debundle the MWCNT in aqueous medium followed by mixing with the polymer matrix . Researchers have also employed the idea of modifying the MWCNT surface by ionic liquids to reduce the bundling problem thus increasing its homogeneity in polymer matrix . However, processes like sonication, freeze drying, etc.…”

Improving mechanical and electrical properties of fluoroelastomer nanocomposites by incorporation of low content of reduced graphene oxide via fast evaporation mixing

“…AFM is a useful tool to observe surface topography of nanocomposites on a nanometric scale. Besides, with the aid of 3D images in nanometric scale, it's also suitable to reflect the nanofiller dispersion in the matrix . The 2D and 3D topographical images of the pristine FKM and FKM/RGO compounds were shown in Fig.…”