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This study evaluates the effect of 1% to 5% NaOH treatments of cotton stalk particles on the chemical composition and physical and mechanical properties of particleboards produced with this material. Gas chromatography and Fourier transform infrared (FTIR) spectroscopy indicated that the extractive, hemicellulose, and lignin content of the particles decreased during the alkali treatments, whereas the cellulose content increased. Thermogravimetric analysis (TGA) indicated that the untreated particles exhibited higher thermal stability than the particles treated with NaOH. The decrease in thermal stability of alkali-treated particles seems to be due to degradation of chemical components. Alkali treatments raised water absorption (WA) and thickness swelling (TS) of the produced particleboards. Except for 1% NaOH, the treatments reduced the modulus of elasticity (MOE), modulus of rupture (MOR), and internal bond (IB) strength in relation to the board made with untreated particles. The 1% NaOH treatment of cotton stalks was more effective and beneficial, leading to particleboards with satisfying MOE, MOR, and IB values that met the requirements for general-purpose particleboards used in dry conditions, as indicated by the TS-EN 312 (2012) standard. [ABSTRACT FROM AUTHOR]

Significant effects of organoclay and poly(melamine-co-formaldehyde)- methylated (PMFM) impregnation on the mechanical, morphological, and thermal characteristics of raw pulai wood were investigated in this work. The material’s modulus of elasticity (MOE) as well as the maximum compression force (MCF) of the impregnated organoclay/PMFM pulai wood samples were optimized using a designed experiment. The MOE and MCF models had R2 values of 0.9228 and 0.8340, respectively. After the impregnation of organoclay/PMFM pulai wood samples, the MOE and MCF increased considerably, indicating that the pulai wood's mechanical characteristics had improved. The compositional analysis verified the polymerization and dispersion of organoclay and PMFM. Using Fourier transform infrared spectroscopy, reduction in the hydroxyl groups was detected. The impregnated organoclay/PMFM pulai wood samples had successfully filled the pores and cell cavities, as seen by scanning electron microscopy. The thermal stability of the impregnated organoclay/PMFM pulai wood samples was better than that of the raw pulai wood, with a higher glass transition temperature as determined by differential scanning calorimetry. The thermogravimetric study revealed that the impregnated organoclay/PMFM pulai wood samples had higher decomposition temperatures than the raw pulai wood sample. [ABSTRACT FROM AUTHOR]

Four types of treated wood (TW) were prepared by the impregnation of solid wood each with a solution of 4-methyl catechol at pH 8, a solution of 4-methyl catechol at pH 9, a solution of 4-methyl catechol at pH 10, and a solution of 4-methyl catechol at pH 11. These TW were characterized by Fourier transform infrared spectroscopic, X-ray diffraction (XRD), scanning electron microscopic, 3-point bending, freefree- vibration, and thermo-gravimetric analysis. FT-IR result showed that TW had more than one carbonyl absorbance band between 1745 and 1690 cm-1, while raw wood had only one carbonyl absorbance band in this regard. TW at pH levels of eight and nine showed higher crystallinity index (CIXRD) than that of raw wood. The SEM micrograph of TW at pH 8 had a smoother surface compared with other treated wood and raw wood. The modulus of elasticity (MOE), and modulus of rupture (MOR) of TW at pH 8 and pH 9 significantly increased. The raw wood exhibited a higher water uptake compared with the TW. The TGA results showed that TW were thermally less stable between 267 and 400 °C than raw wood. [ABSTRACT FROM AUTHOR]