Guobing Xiong¹, Lu Hong², Zehui Ju³, Xiaoning Lu^3,*, Juwan Jin^3,*

Journal of Renewable Materials, Vol.11, No.9, pp. 3447-3461, 2023, DOI:10.32604/jrm.2023.027430

Abstract The study characterized the curing behaviors of phenol formaldehyde (PF) resin under different vacuum degrees and explored the properties of 9-ply plywood panels hot-pressed under both vacuum and atmospheric conditions. The changes in core temperature and moisture content of the plywood mats during hot pressing were investigated as well. It was found that the gel times and gel temperatures of PF resin decreased with the increase of vacuum degree using a self-made device. FTIR spectra indicated the degree of polycondensation of hydroxymethyl gradually increased with the increase in temperature. It was also observed that a higher degree of vacuum led… More >

Zhigang Wu^1,#, Sicheng Chen^1,#, Jiankun Liang², Lifen Li¹, Xuedong Xi^3,4, Xue Deng¹, Bengang Zhang^3,*, Hong Lei^4,*

Journal of Renewable Materials, Vol.9, No.11, pp. 1959-1972, 2021, DOI:10.32604/jrm.2021.016786

Abstract Alkali lignin was processed by plasma and then used in modification of phenol formaldehyde resin in this study. Chemical structural changes of lignin which was processed by plasma as well as bonding strength, tensile property, curing performance and thermal property of the prepared phenol formaldehyde resin which was modified by the plasma processed lignin were analyzed. Results demonstrated that: (1) Alkali lignin was degraded after the plasma processing. The original groups were destroyed, and the aromatic rings collected abundant free radicals and oxygen-containing functional groups like hydroxyls, carbonyls, carboxyls and acyls were introduced into increase the reaction activity of lignin… More > Graphic Abstract