Flexural properties epoxy nanocomposites

Table 9.19 Effect of water treatment on flexural properties of clay-epoxy nanocomposites. Reprinted from [47] with permission from Elsevier.

Zainuddin S, Hosur MV, Zhou Y, Narteh AT, Kumar A, Jeelani S. Experimental and numerical investigations on flexural and thermal properties of nanoclay-epoxy nanocomposites. Mater Sci Eng A 2010 527 7920-7926. 

Incorporation of monofunctional epoxy POSS into an amine-cured epoxy network increased and broadened the Tg without changing the crosslink density and enhanced the thermal properties. Additionally, it was found that the thermal and thermal-mechanical properties of resultant styrene-POSS vinylester resin nanocomposites were dependent on the percentage of POSS incorporated into the resin [171]. Over a range of POSS incorporations, the Tg of the copolymers changed very little, but the flexural modulus increased with increasing POSS content. 

The epoxy as well as nanocomposite samples kept in water medivun show a reduction in mechanical properties. The water absorption leads to plasticizing effect in the epoxy matrix, resulting in reduction in interfacial strength between the epoxy and reinforcing particles, which reduces flexural strength and modulus (Table 9.19). 

Loos and co-workers [64] studied the effect of CNT on the mechanical and viscoelastic properties of epoxy matrices. Bisphenol A based epoxy resin nanocomposites were prepared with various small proportions of single-walled carbon nanotubes (SWCNT) and then investigated using acetone as a diluent to reduce the resin viscosity, and the products after removal of the solvent were characterised by FT-IR, Raman spectroscopy, thermogravimetric analysis (TGA), DSC, DMA, tensile, compression, flexural and impact testing, and SEM of the fracture surfaces. The effects of small amounts of SWCNT on mechanical and viscoelastic properties of the nanocomposites are discussed in terms of structural changes in the epoxy matrix. 

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