Pyrolysis, kinetics and thermodynamic analyses of rice husks/clay fiber-reinforced polylactic acid composites using thermogravimetric analysis

Abstract

In the context of processing, utilization and disposal of polylactic acid composites, pyrolysis is a promising technique that addresses this complex synergy. In this work, pyrolysis kinetics and thermodynamic parameters of rice husks/clay fiber-reinforced PLA composites were investigated using Kissinger–Akahira–Sunose (KAS) and Ozawa–Flynn–Wall (OFW) at multiple heating rates (16, 25 and 34 °C min−1). PLA composites’ pyrolysis followed a single-step degradation process. The flammability indices, combustion characteristic indices and mean reactivities obtained for the PLA composites are much lower than those for neat PLA (2.00 × 10−5–2.44 × 10−5% min−1 °C−2, 0.87 × 10−8–1.79 × 10−8% min−2 °C−3 and 6.97 × 10−3–8.04 × 10−3% min−1 °C−1, respectively) which signals that rice husks and clay improved flame retardancy of accruing PLA composites. The average activation energy values obtained from the KAS method were found to be in ranges 137.83–143.99 kJ mol−1 and 124.51–133.95 kJ mol−1 for raw and modified rice husks/clay fiber-reinforced PLA composites, respectively. Corresponding activation energies for raw and modified rice husks/clay fiber-reinforced PLA composites from the OFW method were 141.24–146.92 kJ mol−1 and 128.17–137.50 kJ mol−1, respectively. By comparing activation energy and enthalpy, it was found that the composites were favored to format activated complex due to the low energy barrier.

Colloidal Gibbsite Nanoparticle/Polyacrylamide Composites for Flame-Retardant Materials

“…TGA and DTG provide tremendous potential to characterize the thermal stability and composition of materials, including polymers and composites . They offer quantitative and qualitative data for determining the kinetics and thermodynamics of the pyrolysis process of the samples . In this work, PAM and GS/PAM composites were evaluated using TGA at four heating rates (5, 10, 15, and 20 °C/min) from 30 to 900 °C.…”

“…32 They offer quantitative and qualitative data for determining the kinetics and thermodynamics of the pyrolysis process of the samples. 48 In this work, PAM and GS/PAM composites were evaluated using TGA at four heating rates (5, 10, 15, and 20 °C/min) from 30 to 900 °C. Their TGA and DTG curves at a heating rate of 10 °C/min are represented in Figure 3.…”