Conductivity and mechanical properties of composites based on MWCNTs and styrene‐butadiene‐styrene block™ copolymers

Abstract

Composites based on multiwall carbon nanotubes (MWCNTs) and the block copolymer styrene-butadiene-styrene with two different contents of styrene have been investigated and their electrical conductivity and mechanical properties have been evaluated. The composites were prepared by a solution casting procedure, using a dispersant agent for the MWCNTs. Conductivity values of 10 À4 and 1.6 S cm À1 have been obtained for samples containing 1 and 12 wt % of MWCNTs, respectively. The percolation threshold achieved for these systems was $0.25 wt %.According to dynamic mechanical analysis, the MWCNTs interact with both phases of the copolymers, acting as a reinforcement filler, whereas the dispersant agent acts as a plasticizer. However, it was shown that the reinforcing effect of the MWCNTs overcomes the latter, resulting in an overall improvement of mechanical properties of the composites.

Electro-mechanical properties of triblock copolymer styrene–butadiene–styrene/carbon nanotube composites for large deformation sensor applications

“…Applying this approach, composites using carbon nanoallotropes and thermoplastic elastomeric materials (TPE) have found applications in electrostatic charge dissipation, electromagnetic interference shielding, field emission devices, pressure or deformation sensors and aerospace [2]. Due to the large strains and high impact resistance, such materials are also promising for the substitution of silicon based force and deformation sensors as well as strain gages [3].…”

“…Within this field, thermoplastic elastomeric polymers with CNT are gaining increasing attention [2,8,9,12]. The electrical properties of these composites are strongly dependent on CNT concentration present in the composite [2,8,9] and on chemical modification of the surface of the CNT's [8,9,13].…”

“…Conductive TPE composites exhibit excellent mechanical and electrical properties and can be used as artificial muscles, electromechanical actuators, touch control, switches and shapememory polymers [2]. Small amounts of CNT incorporated in the matrix can enhance the mechanical properties, electrical and thermal conductivity.…”

“…Several chemical agents are used for this purpose, including xylene [2], dehydrated ethyl alcohol [5], toluene and ethanol [6], among others, in order to achieve higher composite homogeneity [2,7] and reduced the clusters size [2]. By applying such dispersion agents, the aims are to obtain a better dispersion of the fillers within the polymer matrix and, as a result, to decrease the percolation threshold and enhance electrical properties while maintaining proper elastomeric behavior [8,9].…”

Citotoxicidade e genotoxicidade de nanotubos de carbon

“…A importância dos estudos de cito-e genotoxicidade dos NTCs ocorre porque centenas de publicações sugerem que esse nanomaterial poderá vir a ser utilizado em baterias de íons de lítio, supercapacitores, células a combustível, células fotovoltaicas, em catálise heterogênea, desenvolvimento de membranas para captura de CO 2,16 materiais compósitos poliméricos, 17,18 filtros para a remoção de vários compostos orgânicos voláteis e tratamento de efluentes, 19,20 materiais micro/nanoestruturados 21,22 e várias outras aplicações tecnológicas. 23 Estudos também têm demonstrado que NTCs podem afetar o crescimento de plantas, atuando como um eventual adubo.…”