Preparation from different lignins

Other lignins can be reacted with this chemistry. Table 7 shows synthesis data for the preparation of poly(lignin-g-(1-amido-ethylene)) from several different lignins. Sample 1 is a kraft pine lignin grafted in a reaction coinitiated with sodium chloride. 

Gottlieb and Geller (34) reported further to have obtained an enzyme preparation from mushroom spawn, which they claim to catalyze a reaction between native lignin and oxygen. They believe that this enzyme is different from other phenol oxidases heretofore studied. It was later reported that the enzyme acts on low molecular weight water soluble compounds closely related to native lignin. The nature of these compounds was, however, not determined (35). 

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). 

Hemicellulose was reclaimed from industrial soda bagasse spent pulping liquor by precipitation with methanol as was done in earlier studies 2-5). The hemicellulose precipitate obtained was submitted to different degrees of washing with 50% aqueous methanol, resulting in hemicellulose preparations containing different quantities of ash and lignin. The pH of the hemicellulose was adjusted and borax or CaCh added, after which it was dried and ball-milled to the indicated particle sizes. 

Telysheva and co-workers [148, 160] followed the capacity to scavenge free stable radicals of DPPH (l,l-diphenyl-2-picryl hydrazyl) on the different lignin preparations (e.g. methanol soluble fractions from commercial softwood kraft and hydrolysis lignins). 

A schematic description of different methods for the isolation of LCC preparations from wood is summarized in Fig. 2. Certain fractions of hardwood and annual plant LCCs can be extracted with diluted NaOH (0.3%) under mild conditions (1 h reflux under nitrogen atmosphere) [16-19,25-28]. The alkali-soluble material contained mostly lignin and up to 50% of carbohydrates and therefore was referred to as alkali-soluble LCC (Alk-LCC) (Fig. 2). The Alk-LCC is enriched with H- and G-units and phenolic OH as compared to the bulk lignin in the same species. In addition, significant differences in the number of interunit linkages are observed in Alk-LCC and bulk lignin [25-28]. 

Within research on utilization of enzymatic processes for fibre extraction two preparations of different bacterial laccases (NS 51002 and NS 51003) were used and the third enzyme used was Pectinex 1OOL. The laccases are oxidoreductases which react directly with oxygen it is an important oxidant used in the paper industry to eliminate lignin from the pulp. 

Four kinds of hydrolysis lignin (HL) samples obtained from different industrial plants in New Zealand and three different places in Russia (Archangelsk, Lobin-sky, and Kirovsky) were used. Lignin powder samples were dissolved in DEG or polyethylene glycol (PEG) and HL polyols were prepared [54]. Rigid polyurethane (PU) foams were obtained through the reaction of HL polyols with MDI. Optimum reaction conditions in order to attain designed properties were examined. 

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