Synthesis of carbon functionalised silica C@SiO2 from rice husk and use as flame retardant filler

The present research describes the extraction of carbon functionalised silica(C@SiO2) from rice husk at lower temperatures with efficient yield and mass balance. The structure and properties of C@SiO2 were established by infra-red spectrometer (FT-IR), X-ray diffractometer(XRD), scanning electron microscope (SEM), transmission electron microscope(TEM), Thermo gravimetric analysis (TGA) and other standard ASTM methods. The obtained C@SiO2 was used as filler in polypropylene and its effectiveness in comparison to commercial silica gel (SG) on the account of structure, processability, hardness, and burning behaviour. The analytical result revealed the successful dispersion of C@SiO2 in the PP matrix during melt mixing. The composite exhibits comparable processability, and mechanical strength with a 10% loaded silica, along with the improvement in flame retardancy in terms of burning time of 30%, ignition time of 40%, and ash content of 25%. The observed properties of C@SiO2 fillers were explained based on the chemical structure to establish the importance of materials and methods for valorisation of widely available agro-waste.