Effect Of Nanoclay On The Toughness Of Epoxy And Mechanical, Impact Properties Of E-glass-epoxy Composites

Abstract

Organically modified montimorillonite nanoclay was added to the epoxy and E-glass-epoxy composites. The influence of nanoclay content (varied between 0 to 5wt %) on the relative crosslink density and the fracture toughness of the epoxy matrix was studied. Differential scanning calorimetry (DSC) indicated that the amino functional groups present on the nanoclay react with the epoxy matrix to increase the crosslink density of about 13 and 18% at 3 and 5wt% addition, respectively. The toughness of the epoxy composites increased by 25% at 3wt% addition of nanoclay, whereas, it decreases at 5wt%. Flexural strength and tensile strength of the E-glass-epoxy composites were found to increase by 12% and 11% respectively at 3wt% addition of nanoclay, while at 5wt% addition these properties decreased due to the matrix embrittlement. Interestingly matrix embrittlement is found to be beneficial in increasing the impact resistance due to spallation of embrittled matrix that ensures the dissipation of the impact energy. 5wt% nanoclay addition increases the impact strength by 29% and reduces the back face bulge of composite by 31%. These results may lead to the design and realization of glass-epoxy composites with better impact strength.design and realization of glass-epoxy composites with better impact strength.

Hygrothermal chamber aging effect on mechanical behavior and morphology of glass fiber-epoxy-nanoclay composites

“…Surface modified nanoclay addition leads to an increase in cross-linking density of epoxy, giving rise to increased toughness and tensile properties of the epoxy as a result of the load transfer interaction from the matrix to reinforcement [23]. The higher aspect ratio of nanoclay might have enhanced the tensile strength of the polymer matrix by enhancing the nanoclay interaction surface vicinity [24,25]. Nanoclay serves as an active stress transfer constituent in the ENCs, leading to plastic deformation in the epoxy and eventually increasing the tensile strength [4].…”

The effect of nanomodified epoxy on the tensile and flexural properties of Napier fiber reinforced composites

“…This significantly explains the distinguishable characteristic of the nanoclay filler which has a high specific area imparts substantial improvements, even when present in small amounts. An investigation on the flexural strength of nanoclay‐E‐glass‐epoxy composites found the highest strength when incorporated with only 3 wt% of nanoclay loading . However, the addition of a higher amount of nanoclay filler up to 5 wt% gradually reduced the composites' strength because of the agglomerations that occurred at the higher nanoclay ratio, causing the embrittlement of the matrix.…”

“…This suggested that, at the 5 wt% nanoclay content, the composites absorbed more work of fracture and consequently showed higher mechanical resistance. Several studies have proved that, with the addition of nanofiller to a composite, the crack propagation induced by any test was forced to follow a tortuous path . As a result, the nanocomposites showed better resistance to the applied force, describing tougher behavior, compared to the pristine one.…”

Compression after Impact Behaviour and Failure Analysis of Nanosilica-Toughened Thin Epoxy/GFRP Composite Laminates

“…Significant enhancement in fracture toughness of the matrix system was observed in various cases through key toughening mechanisms like crack pinning, crack deflection, crack bridging, and filler debonding [7,8]. Researchers endeavored to use nanofillers, like single-walled carbon nanotubes (SWCNT), double- walled carbon nanotubes (DWCNT), multi-walled carbon nanotubes (MWCNT) [9,10,11,12], graphene [13,14,15], nanoclay [16,17,18], and nanosilica [19,20,21] into various polymers and reported the effect of reinforcement in polymer composites. However, reinforcing nanofillers into the polymer matrix does not always enhance the fracture toughness and modulus of the composite material.…”

“…Johnsen et al [21] investigated the influence of nanofillers of different sizes as toughening agents and also explored the associated toughening mechanisms. Krushnamurthy et al [18] investigated the effect of nanoclay on the toughness behavior of E-glass composite laminates. It was noted that the toughness of the epoxy composite laminates increased by 25% at 3 wt% of nanoclay.…”