Abstract
The fatigue properties of the polymer nanocomposites reinforced with a hybrid nano-filler system have seldom studied before. Accordingly, epoxy nanocomposites with various multi-walled carbon nanotube (MWCNT)/graphene nanoplatelet (GNP) filler ratios were prepared to study comprehensively the synergistic effect of the hybrid nano-fillers on the monotonic and cyclic mechanical properties of the nanocomposites. The quasi-statically tensile properties and fatigue-life curves were experimentally determined using uncracked bulk specimens. Additionally, pre-cracked specimens were utilized to study the fracture toughness and fatigue crack growth rate of the nanocomposites. A synergistic index based on the properties of the nanocomposites with individual types of filler was proposed to evaluate the synergistic effect of two employed nano-fillers on the studied properties. The index was verified to be a highly discriminatory tool to evaluate the synergistic effect of hybrid nano-fillers on the studied mechanical properties. The experimental results show that the composites with a MWCNT:GNP ratio of 1:9 have the higher monotonic and fatigue properties than those with other filler ratios. Adding appropriate amount of CNTs can prevent the agglomeration of GNPs. The flexible CNTs bridge adjacent GNPs to constitute a favorable network for load transfer. Moreover, there is a linear relationship between the static and fatigue strengths of the studied nanocomposites. Integrated analysis of experimental data and a fracture surface study reveals that the dispersion of nano-fillers influences the mechanical properties significantly. The crack deflection effect due to the path bifurcation caused by encountering the filler cluster and the filler bridging effect are the main reinforcement mechanism of the studied properties.
Highlights
With an increasing number of industrial applications, carbon particles with different nano-dimensionalities, such as fullerene, carbon black, nano-diamonds (NDs), carbon nanotubes (CNTs), graphite-family nano-sheets, graphene aerogels, etc.; have been widely employed to improve the mechanical, electrical, and thermal properties of polymer materials
In 2018, Sahu et al employed NDs, CNTs, and graphene nanoplatelets (GNPs) to study the synergistic effect of carbon nano-fillers with various dimensionalities on the mechanical properties of high-density polyethylene (HDPE) [23]
Riberio et al studied the mechanical properties of the epoxy-based nanocomposites reinforced by hexagonal boron nitride (h-Br), graphene oxides (GO) and combined GO/h-Br filler systems [24]
Summary
With an increasing number of industrial applications, carbon particles with different nano-dimensionalities, such as fullerene, carbon black, nano-diamonds (NDs), carbon nanotubes (CNTs), graphite-family nano-sheets, graphene aerogels, etc.; have been widely employed to improve the mechanical, electrical, and thermal properties of polymer materials. Various mixing techniques have been adopted to obtain uniform dispersion of nano-particles in the matrix because the degree of distribution of the reinforced particles influences the mechanical properties significantly. The mechanical properties of the polymers mixed with individual types of carbon nano-filler have been well studied, and some review. Adding a small amount of carbon nano-fillers can increase the mechanical properties of the polymers significantly, and the aggregates owing to the employment of excessive nano-fillers are deleterious to the mechanical properties. The reinforced achievements of carbon nano-particles on the mechanical properties of polymers increase with the dimensionality of the employed nano-reinforcements. The aggregation due to the larger aspect ratios of nano-fillers has detrimental influences on the mechanical properties of the nanocomposites
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
