Bagasse lignin adhesive

Soda Bagasse Lignin Adhesives for Particleboard Preliminary Results... 

Table III. Beech Strip Strengths of Hydroxymethylated Bagasse Lignin Adhesives Crosslinked with Various Fortifiers...

Table IV. Internal Bond Strength of Particleboard, 12-mm-Thick, Prepared from Soda Bagasse Lignin Adhesives (10% on Dry Chips) After Pressing at 170 °C for 15 Minutes...

However, lignin may find application as a suitable wood-composite adhesive in adhesive formulations if chemically modified in some manner. In this respect, the recent developments with soda bagasse lignin-resorcinol-formaldehyde and lignin-isocyanate adhesives allow for some cautious optimism for the future. 

In this chapter, the development of a thermosetting adhesive from soda bagasse lignin is described. The research has concentrated on the development of interior-grade adhesives for particleboard. The local market for exterior boards is smaller than that for the interior panels, and adhesives for exterior boards are already covered by an excellent range of tannin-based adhesives. 

Table II. Strength of Cold-Setting Wood Adhesives Prepared from Industrial Bagasse Lignin (5)...

Van der Klashorst, G. H Cameron, F. A Pizzi, A. The Utilization of Soda Bagasse Lignin in the Manufacture of Thermosetting Wood Adhesives. Paper presented at the International Symposium on Wood and Pulping Chemistry, April 1987. 

Lignin was obtained from an industrial soda bagasse spent liquor as before (5). The lignin was initially evaluated as a thermosetting adhesive by the beech strip test. Prior to its application as adhesive, the lignin was reacted with formaldehyde in alkali at temperatures below 60 °C to afford a hydroxymethylated lignin (fi). The hydroxymethylation reaction was done at pH 12 and 13, and samples of the reaction mixtures were evaluated on beech strips with overlaps of 25 x 25 mm, cured for 4 hours at 90 °C and 12% equilibrium moisture content. 

Soda bagasse spent liquor thus contains two useful renewable polymeric chemical feedstocks hemicellulose and lignin. The uses developed so far for these materials are depicted graphically in Figure 1. The use of the hemicellulose as a corrugated board adhesive is discussed in this chapter. 

Pizzi and colleagues (Chapter 7) have cleverly taken advantage of the special circumstances offered in the kraft lignins from bagasse to develop both cold-setting wood laminating and particleboard adhesives. Lignin oxidations... 

Phenol-formaldehyde resins are among the most important polymeric adhesives used in the wood based composite panel manufacturing industries [1]. Phenolic resins are prepared by the reaction of phenol or any substituted phenol with formaldehyde or other aldehydes, in the presence of acidic or basic catalyst. The price of phenol depends on the oil price and is likely to ever increase due to shortage of fossil resources. Hence, several lignin substitute products based on renewable materials derived from annual plants such as flax [2, 3] or kenaf [4], agricultural waste such as sugar cane bagasse [5] and wheat straw [6] or by-products from the... 

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