Bowen Liu¹, Yunxia Zhou¹, Hisham Essawy², Shang Feng¹, Xuehui Li¹, Jingjing Liao¹, Xiaojian Zhou^1,3,*, Jun Zhang^1,*, Sida Xie¹

Journal of Renewable Materials, Vol.10, No.11, pp. 3009-3024, 2022, DOI:10.32604/jrm.2022.019848

Abstract This study presents easily prepared free formaldehyde bio-based foam based on a prepared thermosetting resin comprising tannin–lignin–furfuryl alcohol-glyoxal (TLFG) via mechanical stirring in presence of ether as a foaming agent. The foam was developed through a co-polycondensation reaction of glyoxal and furfuryl alcohol with condensed tannin and lignin, which is a forest-derived product. Investigation using scanning electron microscopy (SEM) showed more closed-cell structure without cracks and collapse in the TLFG foam, with a higher apparent density with respect to tannin–furanic–formaldehyde (TFF) foam. Differential scanning calorimetry (DSC), dynamic thermomechanical analysis (DTMA), and thermogravimetric analysis (TGA) investigations revealed that the curing process… More >

Yuan Zhang¹, Ping Li¹, Yiqiang Wu^1,2, Guangming Yuan^1,2, Xianjun Li^1,2, Yingfeng Zuo^1,2,*

Journal of Renewable Materials, Vol.8, No.11, pp. 1473-1488, 2020, DOI:10.32604/jrm.2020.011788

Abstract The Chinese fir wood was impregnated using a cyclic increasingpressure method (CIPM) with phenolic prepolymers as the impregnating modifier. Unmodified Chinese fir and progressive increasing-pressure method (PIPM) impregnated Chinese fir were used as reference samples and were compared and analyzed. The product’s chemical structure, internal morphology, crystal structure, and heat resistance were characterized. The transversal and longitudinal sections showed better filling effects, so that it bore greater external loading and reduced the water storage space. CIPM infused more phenolic prepolymer into the Chinese fir. Not only producing more physical filling but also forming more hydrogen bond associations and chemical bond… More >