A bio-based approach to simultaneously improve flame retardancy, thermal stability and mechanical properties of nano-silica filled jute/thermoplastic starch composite

This novel work discusses the simultaneous improvement in flame retardancy, thermal stability and mechanical performance of jute/thermoplastic starch (TPS) composite through the incorporation of nano-silica particles (1–4 wt% of starch) as a bio-based flame retardant. The enhancement in mechanical properties of the composite has been achieved due to hydrogen bonding and the formation of a strong Si–O–Si covalent bond between silica and jute/TPS which has been verified through Fourier transform infrared spectroscopy (FTIR). Tensile, flexural and impact strengths of the jute/TPS composites were observed to increase respectively by 23%, 97% and 70% after incorporation of nano-silica. The improvement in interfacial bonding was verified using scanning electron microscopy (SEM). Cone calorimetry and UL-94 burning tests revealed that the composites have excellent sustainability towards flame supported by a 128% reduction in burning time, 12% decrease in total heat released and 14% decrease in peak heat release rate. Thermogravimetric analysis (TGA) showed thermal stability through increase in decomposition temperature due to a 37% increase in residual char. Furthermore, biodegradation of the developed composites was proven through a soil burial test. Hence, the research provides the design of novel biodegradable material with simultaneous enhancement of mechanical properties, thermal stability and flame-retardancy, which expands the applications of thermoplastic composites in automobile, aerospace and structural applications.