Utilization of Softwood Kraft Lignin as Adhesive for the Manufacture of Reconstituted Wood

Comparison on structural modification of industrial lignin by wet ball milling and ionic liquid pretreatment

“…In order to improve the reactivity of lignin, many methods have been proposed, including methylation, demethylation, acetylation, etc. Wu and Zhan’s study (2001) showed that the content of methoxyl groups in wheat straw soda lignin, decreased from 10.39% to 6.09% after demethylation, while the contents of the phenolic hydroxyl and carboxyl groups increased from 2.98% and 4.58% to 5.51% and 7.10%, respectively [33]. investigated the methylation of pine Kraft lignin which revealed that about 0.36 mole of hydroxymethyl group per C 9 unit was introduced.…”

Conversion of technical lignins to functional materials with retained polymeric properties

“…Zhao et al reported a kinetic study regarding the hydroxymethylation of pine kraft lignin. They concluded that about 0.36 mol of CH 2 OH/C9 units was introduced under the optimal reaction conditions, of which about 0.33 mol was introduced on the C-5 of guaiacyl moieties via the Lederer-Manasse reaction [78].…”

Wood production, wood technology, and biotechnological impacts

“…Many studies on replacing parts of conventional PF-and also UF binders have been published and reviewed in the literature , Abe 1987, Lewis & Lantzky 1989, Shiraishi 1989, Roffael & Dix 1991,b, Lisperguer & Solis 1999, Lisperguer et al 2000, Feldman 2002, Turunen et al 2002, Tejado et al 2007a; see also Chapter 18 of this book). Replacing up to 50% of all phenol can give ligninphenol-formaldehyde adhesives (LPFs) of equal or often also better bond strength but, for some lignin types, the thermo-stability decreases and pressing times may increase (Kazayawoko et al 1992, Sellers et al 1994, Zhao et al 1994, Olivares et al 1995, Vázquez et al 1997,b, Wu & Zhan 2001, Cetin & Özmen 2002, Gosselink et al 2004b, Khan et al 2004a,b, Khan & Ashraf 2005. In view of economics, replacement of phenol by lignin in black liqour from kraft pulping is reported to reduce the cost of adhesives for bamboo plywood in China by a factor of 28.7% and, by national criteria, the produced bamboo plywood had better qualities (Wang, Y.Y.…”