Lignins INDEX

When testing for a tannin reserve or tannin index, the presence of natural color aids detection. Testing for tannin is simple and relatively accurate using either a permanganate reduction test (development of permanent purple color) or lignin/tannic acid polymer test (tungstate blue color). 

Figure 8. Gel filtration of ethylated (/ -0-4)-(/ -/ )-DHP 16. Solid line Ethylated (/ -0-4)-(/ -/ )-DHP 16 after removal of low molecular weight fractions. The column was calibrated with (/ -0-4)-(/ -/ ) lignin substructure model trimer 6 (molecular weight 642) /3-0-4 lignin model dimer 1 (molecular weight 348) and polystyrenes of molecular weight 9000, 4000 (void), 2200 (indicated by A). Column Sephadex LH-20, 1.1 x 48 cm. Eluent DMF, 13.5-14.4 ml/hr. Detector Refractive index detector RI-2 (Japan Analytical Industry Co., Ltd.).

Figure 2. Ratio of peak areas of the phenolated lignin to unreacted phenol as an index of phenol consumption during phenolysis.

Although the lignins do not perform adequately as full binders, they can be used as extenders. Now the resin supplies the benzylalcohol functionality and the lignins (and wood chips) need only supply alcohol groups to make ether linkages. The results for data on methylolated lignins are expressed in Table II as indices. The index is obtained by dividing the... 

IB = internal bond strength F = suffix used to indicate methylolated sample WtpF = weight of PF resin in a lOOg board WtML = weight of methylolated lignin in a lOOg board Rf = total aliphatic OH index Ra = total alcohol index... 

Table II shows the correlation of wt% of polyol containing phosphorous in PU with 20 wt% of lignin with oxygen indices which were obtained according to the procedure of JIS method. In this method, the inflammability of a sample is tested in a mixture of oxygen and nitrogen under a constant flow rate of the mixture. The oxygen index is the minimum concentration of oxygen in which a sample is inflammable. The oxygen index for PU without phosphorous and those for PU s with phosphorous are 19.3 and 24.6, respectively. That is, qualitatively, PU s with phosphorous were not inflammable in air and PU without phosphorous was inflammable. This indicates that PU becomes less inflammable by the addition of 3 wt% of polyol containing phosphorous.

Index Entries Steam explosion Douglas fir oxygen delignification enzymatic hydrolysis lignin. 

Index Entries Reaction kinetics glucose decomposition dilute acid hydrolysis kinetic modeling acid-soluble lignin acid-base catalysis rules. 

Pulp Kappa3 Lignin % Copper b index Carboxyl index... 

In conclusion, even though there is the definite correlation between carboxylic group index and minimum in respect to graftability in our system, a detailed work with model compounds would be required to futher elucidate the mechanism of lignin participation in the copolymerization reaction. 

Calculation of Lignin Concentration from Refractive Index... 

To calculate lignin concentration from refractive index of the specimen, calibration values are required. For measurements in the secondary wall, value Na in Eq. (3) is the refractive index of the S2 region in a matched specimen of holocellulose. This value varies from specimen to specimen and must be measured each time a new specimen is examined (Donaldson 1985a). The only exception is for earlywood and latewood from the same growth ring. For measurements in the middle lamella, Na has a constant value of 1.516 which... 

The pyrograms of plants or lignins can be evaluated through use of the similarity index (Salo et al, 1989), as defined by the following equation ... 

Ltndberg JJ, Ratsanen S, Niemt R (1982) GC-MS studies on the pyrolysis of wood and lignin Gov Rep Announce Index (US) 1984 84 163-173 Linskens HF, Jackson JF (1986) Gas chromatography/mass spectrometry Springer, Berlin Heidelberg New York Tokyo, 304 pp... 

Rezanowich A, Yean WQ, Goring DAI (1963) The molecular properties of milled wood and dioxane lignins sedimentation, diffusion, viscosity, refractive index increment and ultraviolet absorption Sven Papperstidn 66 141-149 Sarkanen KV, Chang H-M, Allan GG (1967) Species variations in lignin (2) Conifer lignins (3) Hardwood lignins Tappi 50 583-590... 

Lignin has been grafted with ethenylbenzene [43,44] (styrene), 4-methyl-2-oxy-3-oxopent-4-ene [45,46] (methylmethacrylate), 2-propenamide (acrylamide), 2-propene nitrile [47] (acrylonitrile), cationic monomers, anionic monomers, and propenoic acid ethoxylates. An index of compounds listing structure, product name, and trivial name is given in Table 3. Two types of... 

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