Experimental Investigations of Flammability, Mechanical and Moisture Absorption Properties of Natural Flax/NanoSiO2 Based Hybrid Polypropylene Composites

Natural fibre-reinforced polymer composites, recently developed, provide several socioeconomic and sustainability benefits for a wide range of technical applications. The purpose of this study was to look at how natural flax fibre (30 wt%) and silicon dioxide (SiO2 (0, 2.5, 5, 7.5, 10, 12.5 wt%)) affect ternary mixes' mechanical, combustible, and water absorption qualities. A cone calorimetry investigation revealed that the inclusion of nanosilicon dioxide might reduce the polypropylene (PP) composites made from flax fibre's total heat release, total smoke release, and heat release rate. Using 10 wt% nanosilicon dioxide, the heat release rate (255 kW/m(2) to 161 kW/m(2)) was considerably reduced. The mechanical characteristics of the composites increased with the addition of nanosilicon dioxide, and the flexural (50.97 MPa) and tensile strength (42.65 MPa) of the materials reached their maximum values at 10 weight% nanosilicon dioxide. Nanosilicon dioxide exhibited homogeneous dispersal in the flax fibre-based PP composites, with an increase in nanosilicon dioxide from 2.5 to 10 wt%, according to scanning electron microscopy observations on the fractured portion of the hybrids. The lack of a recognisable peak in the X-ray diffraction (XRD) after the integration of nano-SiO2 particles suggests that the granules were homogeneous. The highest water absorption in flax/PP hybrids decreases by 13.25, 15.69, 20.16, 23.63 and 19.52% as compared to pure PP and PP with flax fibre with the addition of 2.5, 5, 7.5, 10 and 12.5 wt% of SiO2 filler, respectively. Based on the obtained results in natural flax fibre-based hybrid composites, the nanoSiO(2) particles worked as barriers to prevent moisture absorption and increase their rigidity. These outcomes imply that such materials would be appropriate for use in moist settings, like those seen in the maritime, outdoor, and packaging sectors. Additionally, these results imply that such composites may find use in sectors where fire safety is a top priority.