Organosolv lignin preparation

Hydroxybutyl (organosolv) lignin (HBL) The organosolv lignin derivative with butylene oxide was prepared in accordance with earlier work (14). The derivative had a hydroxyl content of 6.0% and a number average molecular weight (tf ) of 1500 g mol-1. 

Organosolv lignin-PEG was synthesized using a procedure similar to that used for the lignin model compounds. A 20% dioxane solution of 0.4 M NaOH was prepared. To 6 mL of this solution, 0.6 g of the chloroform soluble fraction of organosolv lignin... 

Carboxymethylation. Few studies were reported on carboxymethylation of lignin preparations [370-373]. Lange and Schweers [371] observed in the reaction of kraft and ethanol organosolv lignin with bromoacetic acid that approximately 60-70% of the total hydroxyl groups were carboxymethylated. The bulk of carboxymethylation was probably involved in the phenolic hydroxyl groups. 

Uraki, Y. Kubo, S. Nigo, N. Sano, Y. Sasaya, T. Preparation of carbon-fibers from organosolv lignin obtained by aqueous acetic-acid pulping. Holzforschung 1995, 49 (4), 343-350. 

The only published report on the use of unmodified lignins for the preparation of epoxy resins was announced by IBM in the late 1990s and dealt with the solution interaction between Kraft or organosolv lignins and various epoxy monomers, followed by a crosslinking operation induced by aromatic diamines [51]. Although details wctc scanty, it was announced that these materials were suitable for application in the electronic industry because of their excellent adhesion on copper, very good dielectric properties and temperature stability up to more than 175°C. 

The organosolv (OS) lignin was prepared from the liquor obtained by treating aspen wood flour with a 70 30 MeOHrwater (v/v) extraction at 165°C for 2.5 hours in a rocking autoclave as described in ref. 23. 

Universal Calibration. The aspen wood lignin samples chosen for this study were prepared by organosolv, steam explosion, dilute acid hydrolysis, and ball-milling procedures. 

Figure 5. Composite MWD diagram showing the calculated distributions of four of the five master fractions obtained from preparative chromatography of organosolv aspen lignin (fraction number 4 to 1 from left to right). The Mw values for the master fractions from left to right are 1,110, 1,310, 2,420, and 8,050, respectively. The insert shows the elution profile of organosolv aspen lignin from the YMC preparative /z-Styragel column (5 x 200 cm). The 30 fractions collected were pooled into the five master fractions shown.

Hydroxy propyl lignin (HPL) Two different HPL preparations were used in this study (12). Blends containing PE and EVA utilized an HPL from organosolv (methanol) lignin from red oak and blends containing PVA and PMMA utilized an HPL from kraft lignin (Indulin-AT from Westvaco Corporation, Charleston, SC). 

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