Fracture toughness and failure mechanism of graphene based epoxy composites

Journal
Composites science and technology  
Volume
97
Start Page
90
End Page
99
Citation
Composites Science and Technology 97 (): 90-99 (2014-06-16)
Publisher DOI
10.1016/j.compscitech.2014.03.014
Scopus ID
2-s2.0-84899805405
Publisher
Elsevier
The present study investigates the effect of addition of three different types on carbon nano-fillers on fracture toughness (KIC) and failure mechanism of epoxy based polymer nano-composites. The carbon nano-fillers were dispersed in the epoxy matrix using a three-roll mill and the three nano-fillers used for this experiment were (i) thermally reduced graphene oxide (TRGO); (ii) graphite nano-platelets (GNP); and (iii) multi-wall carbon nano-tubes (MWCNT). The fracture toughness was measured as a function of weight percentage of the filler using single edge notch three-point-bending tests. The toughening effect of TRGO was most significant resulting in 40% increase in KIC for 0.5wt% of filler. On the other hand, the enhancements in toughness were 25% for GNP/epoxy and 8% for MWCNT/epoxy. Investigations on fracture surface revealed that crack pinning or bi-furcation by TRGO and crack face separation initiated from TRGO contributed to enhance the fracture toughness. Based on the observations, a schematic explaining the crack propagation in graphene/epoxy composite and the interaction of crack front with graphene particles was proposed.
Subjects
A. Nano-composites
B. Fracture
B. Fracture toughness
D. Fractography
D. Scanning electron microscopy
DDC Class
600: Technik
More Funding Information
The authors would like to acknowledge Mr. Varun Gopal student assistant, for his support in sample production. We would also like to acknowledge DAAD-SIEMENS A/10/71620 scholarship for the financial support.