Effect of alkaline treatment on the thermal stability, degradation kinetics, and thermodynamic parameters of pineapple crown fibres

Pineapple crown is generally discarded as waste but constitutes an important source of lignocellulosic fibres. In this work, the effect of alkaline treatment on the chemical composition, pyrolysis kinetics, and thermodynamic characteristics of pineapple crown fibres (PCF) were investigated by chemical composition, Fourier transform infrared spec-troscopy (FTIR), scanning electronic microscopy (SEM), X-rays diffraction (XRD), and ther-mogravimetry. Chemical composition analysis indicated cellulose content increased from 18.93 to 57.00% after NaOH treatment. PCF fibre diameter was reduced from 6.1 to 4.3 mm after mercerization. The FTIR results confirmed the removal of non-cellulosic compounds. XRD analysis indicated fibre's crystallinity index rose from 53 to 62% in reason of NaOH treatment. Thermogravimetric results confirm that alkaline-treated PCF (ATPCF) presented higher thermal stability than non-treated PCF (NTPCF). The solid-state thermal degradation mechanism for NTPCF and ATPCF occurred by the diffusion process and random nucle-ation, respectively. The thermodynamic parameters of NTPCF indicated that a small amount of energy is required to obtain the reaction products and thus bioenergy produc-tion from NTPCF pyrolysis will be easier, while ATPCF required more energy to initiate a degradation reaction and could be used as filler in polymeric composites.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).