Changes in Chemical and Thermal Properties of Bamboo after Delignification Treatment

Abstract

Bamboo delignification is a common method for studying its functional value-added applications. In this study, bamboo samples were delignified by treatment with sodium chlorite. The effects of this treatment on the bamboo’s microstructure, surface chemical composition, and pyrolysis behaviour were evaluated. Field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) were conducted to evaluate these parameters. The FTIR results demonstrated that the lignin peak decreased or disappeared, and some hemicellulose peaks decreased, indicating that sodium chlorite treatment effectively removed lignin and partly decomposed hemicellulose, although cellulose was less affected. The XPS results showed that, after treatment, the oxygen-to-carbon atomic ratio of delignified bamboo increased from 0.34 to 0.45, indicating a lack of lignin. XRD revealed increased crystallinity in delignified bamboo. Further pyrolysis analysis of treated and untreated bamboo showed that, although the pyrolysis stage of the delignified bamboo did not change, the maximum thermal degradation rate (Rmax) and its corresponding temperature (from 353.78 to 315.62 °C) decreased significantly, indicating that the pyrolysis intensity of the bamboo was weakened after delignification. Overall, this study showed that delignified bamboo develops loose surfaces, increased pores, and noticeable fibres, indicating that alkali-treated bamboo has promising application potential due to its novel and specific functionalities.

Dimensionally Stable Delignified Bamboo Matrix Phase-Change Composite under Ambient Temperature for Indoor Thermal Regulation

“…Based on this, the HTB was much more easily soaked with chemical reagent, which was also the reason HTB was chosen as the matrix of DB [ 37 , 38 , 39 ]. The cell wall thicknesses of DB and HTB ( Figure 4 d,f) were measured by using image J and the values were 0.56 μm and 2.49 μm, respectively, confirming that the lignin and partial hemicellulose of HTB were removed during the multi-delignification process [ 40 ]. The cell wall of DB shrinkage rate was 77.5% by compared with that of HTB and gaps between the cells become larger, which provided channels for PEG impregnation.…”

Microwave-Assisted Soda Pulping of the Banana Pseudo Stem (Musa Cavendish) for Pulp and Paper Production: Production, Characterization, and Optimization

“…A large band (3600-3100 cm −1 ) is characteristic of polymeric involvement of hydroxyl groups and .The most noticeable effect of pulping of the banana pseudo stem in FTIR spectra is the disappearance of the bands in the un-treated pseudo stem found at 1115 and 1030 cm −1 arose from the aromatic rings in the plane C-H bending deformation for S-and G-type lignin. Also, the band 855 cm -1 represents the aromatic ring stretch-out plane deformation vibration of aromatic C-H parts of lignin (Gao et al, 2018;Yu et al, 2022). The spectra of the samples were measured within the range of 4,000-400 cm −1 and confirmed removal of certain functional groups after pulping and bleaching processes.…”

Exploring the synergistic effect of inorganic and organic particulates in polyvinyl chloride composites through comparative analysis and accelerated weathering

“…This represents the typical cellulose fingerprint. Low‐intensity lignin is visible between 1500 and 1750, where the bands at 1740 and 1675 cm −1 correspond to non‐conjugated carbonyl stretching and conjugated carbonyl stretching, respectively 31 …”