Influence of halloysite nanotubes on physical and mechanical properties of cellulose fibres reinforced vinyl ester composites

Natural fibres are generally added to polymer matrix composites to produce materials with the desirable mechanical properties of higher specific strength and higher specific modulus while at the same time to maintain a low density and low cost. The physical and mechanical properties of polymer composites can be enhanced through the addition of nanofillers such as halloysite nanotubes. This article describes the fabrication of vinyl ester eco-composites and eco-nanocomposites and characterizes these samples in terms of water absorption, mechanical and thermal properties. Weight gain test and Fourier transform infrared analysis indicated that 5% halloysite nanotube addition gave favourable reduction in the water absorption and increased the fibre–matrix adhesion leading to improved strength properties in the eco-nanocomposites. However, halloysite nanotube addition resulted in reduced toughness but improved thermal stability

Characterisation of mechanical and thermal properties in flax fabric reinforced geopolymer composites

This paper presents the mechanical and thermal properties of flax fabric reinforced fly ash based geopolymer composites. Geopolymer composites reinforced with 2.4, 3.0 and 4.1 wt% woven flax fabric in various layers were fabricated using a hand lay-up technique and tested for mechanical properties such as flexural strength, flexural modulus, compressive strength, hardness, and fracture toughness. All mechanical properties were improved by increasing the flax fibre contents, and showed superior mechanical properties over a pure geopolymer matrix. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) studies were carried out to evaluate the composition and fracture surfaces of geopolymer and geopolymer/flax composites. The thermal behaviour of composites was studied by thermogravimetric analysis (TGA) and the results showed significant degradation of flax fibres at 300 °C

Water absorption, mechanical, and thermal properties of halloysite nanotube reinforced vinyl-ester nanocomposites

Halloysite nanotube (HNT) addition to vinyl-ester resin (VER) is a field yet to contain an in-depth repository of information. This work represents the first study on the development and characterisation of HNT-reinforced VER nanocomposites, and presents findings on their water absorption, mechanical, and thermal properties. VER composites reinforced with HNTs (1, 3, and 5 wt%) were fabricated using high speed mechanical stirring. Weight gain and FTIR spectrum analysis indicated that the addition of 5 wt% HNTs gave perceptible reduction in the water absorption behavior of the samples. Results showed that elastic modulus increased with increasing HNT content. Strength and toughness were also found to steadily increase with increasing HNT content. Favorable strength can be attributable to the large aspect ratio of HNTs, favorable adhesion and dispersion, and the suitable extent of inter-tubular interaction while enhancements to toughness can be attributable to crack bridging, deflection, and plastic deformation mechanisms. Thermal stability of nanocomposites was found remarkably enhanced by the incorporation of HNTs. The thermal stability enhancement and decrease in flammability are attributable to HNT’s barriers for heat and mass transport, presence of iron, and hollow tubular structure