Thermal stability and dynamic mechanical analysis of nano-biofillers blended hybrid composites reinforced by cellulosic Borassus flabellifer L. fiber

Abstract

The aim of this study is to investigate the dynamic mechanical and thermal stability behavior of rice husk nano-biofillers blend epoxy hybrid composites reinforced by Borassus flabellifer L. leaf fiber. The raw Borassus leaf fibers were treated with 5 wt.% NaOH solution to reduce the disadvantages of hydroxyl bonding. Rice husk nano-fillers (RHNFs) were blended with epoxy resin to modify them with 0.25, 0.45, and 0.65 wt.%, respectively, using sonication and mechanical stirring process. The prepared samples were assessed to evaluate the thermal stability, maximum degradation temperature, storage modulus (E′), loss modulus (E″), damping factor (tan δ) and Cole–Cole plot of the composites. EDX spectroscopy was used to confirm the elemental composition of nano-biofillers. The morphology of RHNFs was analyzed using a scanning electron microscope (SEM). The TG analysis confirmed that the 0.45 wt.% RHNFs blended Borassus leaf fiber (BLF) composites exhibited superior thermal stability (371–384 °C). Derivative thermogravimetry (DTG) analysis exposed that the maximum mass-loss degradation temperature of 0.45 wt.% RHNFs blend composites was 411 °C for the first stage and 678 °C for the second stage, which were more than raw and RHNFs blend (0.25 and 0.65 wt.%) composites. Accordingly, improved E′ (959.16–1637.75 MPa), glass transition temperature (T g) from E″ (90.48–97.69 °C) and, T g from tan δ (103.35–109.67 °C) were derived from the modified composites. Owing to the improved dispersion of the nano-filler, the 0.45 wt.% RHNFs blend composites had a homogeneous polymer system, as verified by the Cole–Cole diagram. The analyzed composites are to be used with versatile functionality for their intended purpose.