Synergistic Effect on the Thermomechanical and Electrical Properties of Epoxy Composites with the Enhancement of Carbon Nanotubes and Graphene Nano Platelets.

Yi-Ming Jen,Jui-Cheng Huang

doi:10.3390/ma12020255

Yi-Ming Jen, Jui-Cheng Huang

Open Access

https://doi.org/10.3390/ma12020255

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Abstract

The synergetic effect of adding multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) on the thermomechanical properties and electric resistance of epoxy polymers were experimentally analyzed in this study. The total content of two employed carbon fillers were kept constant at 0.4 wt %, and seven filler ratios between two fillers (MWCNTs:GNPs), i.e., 10:0, 1:9, 3:7, 5:5, 7:3, 9:1, and 0:10, were considered in the experimental program to investigate the influences of employed nano-filler ratios on the viscoelastic and electrical properties of the studied nanocomposites. The thermomechanical properties and the sheet resistance of the nanocomposites were analyzed using a dynamic mechanical analyzer and four-point probe, respectively. Moreover, the thermogravimetric analyzer was utilized to measure the pyrolysis temperature of the nanocomposites. Experimental results show that the synergistic effect of adding two nano-fillers were clear for the improvement of the storage moduli, glass transition temperatures, and electric conductivity. Oppositely, the employment of two fillers has a slight effect on the pyrolysis temperatures of the studied nanocomposites. The composites with the MWCNT:GNP ratio of 1:9 display the most apparent enhancement of the thermomechanical properties. The improvement results from the uniform distribution and the high aspect ratio of GNPs. The addition of a small amount of MWCNTs provides more linkage in the matrix. Moreover, the specimens with the MWCNT:GNP ratio of 1:9 shows remarkable electrical properties, which result from the large contact surface areas of GNPs with each other. The employment of few MWCNTs plays an important bridging role between the layered GNPs.

Highlights

With the demand of electromagnetic shielding devices, conductive coatings, and antistatic materials, the conductive polymer materials have attracted more attention recently [1,2,3]
The obvious synergistic effect on improving the dispersion of hybrid nano-fillers makes the interest to investigate the properties of CNT/graphene or CNT/graphene nano-platelet (GNP) hybrid nanocomposites grows rapidly
multi-walled carbon nanotubes (MWCNTs) spectrum shows slightly stronger than that of as-received MWCNT, and tiny C–H peaks are found in the SDS treated MWCNT spectrum

Summary

Introduction

With the demand of electromagnetic shielding devices, conductive coatings, and antistatic materials, the conductive polymer materials have attracted more attention recently [1,2,3]. The electrical and thermal conductivities of polymers can be achieved by adding two or more carbon nano-fillers with different geometries in the matrix. Among three geometrically different types of carbon nano-fillers, i.e., particles, tubes, and platelets, the carbon nanotube and graphene are the most popular candidates as fillers used to enhance the electrical and thermal conductivities of the polymer materials. Compared with the carbon fillers with other geometrical characteristics, the one-dimensional shape of CNTs makes them potential fillers in the polymer materials to enhance the electrical and thermal conductivities because of their high aspect ratios. Materials 2019, 12, 255 the properties of polymer materials has rapidly increased because graphene has larger aspect ratio than CNTs, which makes it easy for electrical and thermal conduction [4,5,6]. The obvious synergistic effect on improving the dispersion of hybrid nano-fillers makes the interest to investigate the properties of CNT/graphene or CNT/graphene nano-platelet (GNP) hybrid nanocomposites grows rapidly

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Conclusion