STUDIES ON LIGNIN AND RELATED COMPOUNDS: III. GLYCEROL-CHLOROHYDRIN-LIGNIN

1930 ◽  
Vol 3 (1) ◽  
pp. 65-69 ◽  
Author(s):  
Harold Hibbert ◽  
John Bernard Phillips
Keyword(s):  
Previous Evidence ◽  
Wood Meal ◽  
Spruce Wood ◽  
Extraction Agent ◽  
Related Compounds

Glycerol α-monochlorohydrin has been found to be an effective extraction agent for the removal of lignin from spruce wood meal. Previous evidence for the view that a compound is formed between the lignin and the extraction medium is supported by the results of methoxyl and halogen analysis, and those of hydrolysis.

STUDIES ON LIGNIN AND RELATED COMPOUNDS: II GLYCOL-LIGNIN AND GLYCOL-ETHER-LIGNIN

1930 ◽  
Vol 2 (6) ◽  
pp. 364-375 ◽  
Author(s):  
Harold Hibbert ◽  
Léo Marion
Keyword(s):  
Ethylene Glycol ◽  
Monomethyl Ether ◽  
Glycol Ether ◽  
Free Alcohol ◽  
Wood Meal ◽  
Spruce Wood ◽  
Related Compounds

The extraction of spruce wood meal with ethylene glycol in the presence of 0.05% HCl leads to the isolation of a lignin derivative to which the name glycol-lignin is given. If the monomethyl ether of glycol be substituted for the free alcohol, a glycol-ether-lignin is obtained which has a much higher methoxyl content than glycol-lignin. The product of extraction is therefore a compound of lignin and the solvent. A comparison of the methoxyl content of the derivatives obtained from the two lignins by methylation and hydrolysis supports this conclusion. On oxidation, glycol-lignin gives rise to a product which forms a p-bromphenylhydrazone, identical with that obtained from the product of the oxidation of ethylene glycol under the same conditions. On hydrolysis with acids glycol-lignin yields, besides 0.7% formaldehyde, a substance which reduces Fehling's solution.

STUDIES ON LIGNIN AND RELATED COMPOUNDS: XII. METHANOL LIGNIN

1935 ◽  
Vol 13b (1) ◽  
pp. 28-34 ◽  
Author(s):  
Fritz Brauns ◽  
Harold Hibbert
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Methyl Alcohol ◽  
Empirical Formula ◽  
Dimethyl Sulphate ◽  
Compound A ◽  
Wood Meal ◽  
Building Unit ◽  
Spruce Wood ◽  
Related Compounds

Methanol lignin was prepared by extracting spruce wood meal with absolute methyl alcohol, using hydrochloric acid as catalyst. In five small, bomb-tube experiments, methanol lignin preparations having the same methoxyl content (about 21.6%) were obtained, the product in each case being apparently homogeneous. The methanol lignin was acetylated, partially methylated by treatment with diazomethane, and fully methylated with dimethyl sulphate and sodium hydroxide. From the elementary analyses and the ratio of methoxyl in the original methanol lignin to that in the diazomethane-methylated compound a formula for the smallest building unit of the methanol lignin and for the native lignin can be derived. The latter is represented by the empirical formula C47H52O16, or, expanded, C42H32O6(OCH3)5(OH)5.

STUDIES ON LIGNIN AND RELATED COMPOUNDS: XX. METHANOL LIGNIN AND ITS RELATION TO THE SO-CALLED "PRIMARY LIGNIN" OF FRIEDRICH AND DIWALD

1936 ◽  
Vol 14b (1) ◽  
pp. 12-19
Author(s):  
E. G. King ◽  
Harold Hibbert
Keyword(s):  
Structural Change ◽  
Hydrochloric Acid ◽  
Sodium Bicarbonate ◽  
Prolonged Treatment ◽  
Carboxyl Groups ◽  
Preliminary Treatment ◽  
Wood Meal ◽  
Spruce Wood ◽  
And Behavior ◽  
Related Compounds

Pretreatment of spruce wood meal with cold 5% sodium hydroxide decreases the amount of lignin extractable with methanol and anhydrous hydrogen chloride (Hibbert-Brauns method). Such a prior treatment of the wood meal, either in an atmosphere of nitrogen or of air, apparently causes no structural change in the lignin as judged by the methoxyl content. The method of Friedrich and Diwald, which involves a preliminary treatment with 17% hydrochloric acid followed by addition of a hot alcohol, represents a much more drastic process than the Hibbert-Brauns method, as is indicated by the darker color, lower methoxyl content and behavior towards 8–10% alkali of the isolated lignin.Methanol lignin isolated front a resin-free spruce wood meal, previously subjected to treatment with 5% cold alkali in the presence or absence of air, shows no loss of methoxyl groups on treatment with 8–10% alkali; the same is true of the "primary lignin" prepared by the method of Friedrich and Diwald; in both cases the lignin is insoluble in sodium bicarbonate. These facts show that neither methanol lignin nor "native lignin" contains ester methoxyl groups, as assumed by Friedrich and Diwald. Prolonged treatment of methanol lignin with alkali in the presence of air, especially at higher temperatures, apparenthy brings about certain changes in its structure, including possibly the formation of carboxyl groups. The claim of Friedrich and Diwald that their product represents an "unchanged native lignin" is not in accordance with the facts, and their assumption of the presence of carboxyl groups in native lignin is incorrect.

STUDIES ON LIGNIN AND RELATED COMPOUNDS: XXVIII. THE BEHAVIOR OF LIGNIN TOWARDS ACTIVATED HYDROGEN

1936 ◽  
Vol 14b (11) ◽  
pp. 404-407 ◽  
Author(s):  
R. G. D. Moore ◽  
Harold Hibbert
Keyword(s):  
Low Temperatures ◽  
Open Chain ◽  
Wood Meal ◽  
Building Unit ◽  
Negative Results ◽  
Spruce Wood ◽  
Related Compounds

Methylated methanol lignin prepared from fully methylated spruce wood-meal was subjected, at relatively low temperatures and pressures, to the action of hydrogen in the presence of catalysts, and under conditions such that reduction of open-chain ethylenic linkages readily occurs. Entirely negative results were obtained. This pointed to the absence of ethylenic linkages in the lignin building unit.

A STUDY OF THE MECHANISM AND KINETICS OF THE SULPHITE PROCESS

1939 ◽  
Vol 17b (4) ◽  
pp. 121-132 ◽  
Author(s):  
J. M. Calhoun ◽  
F. H. Yorston ◽  
O. Maass
Keyword(s):  
Temperature Coefficient ◽  
Arrhenius Equation ◽  
Practical Interest ◽  
Effect Of Temperature ◽  
Wood Meal ◽  
Spruce Wood ◽  
Mechanism And Kinetics ◽  
Kinetics Of

The rate of delignification of resin extracted spruce wood-meal has been determined in calcium-base sulphite liquor at temperatures from 130 °C. down to 50 °C. No break was found in the temperature coefficient curve at the lower temperatures, the reaction following the Arrhenius equation closely. Possible mechanisms of the reaction are discussed in the light of existing theories, and the effect of temperature on the yield of pulp is pointed out for its practical interest.

Lignin and related compounds. VI. A study of variables affecting the hydrogenolysis of spruce wood lignin using a rhodium-on-charcoal catalyst

1978 ◽  
Vol 56 (7) ◽  
pp. 899-902 ◽  
Author(s):  
James M. Pepper ◽  
Punsri Supathna
Keyword(s):  
Degradation Products ◽  
Initial Pressure ◽  
Alkaline Media ◽  
Reaction Conditions ◽  
Spruce Wood ◽  
The Media ◽  
Relative Abundances ◽  
Related Compounds

The effect of reaction conditions on the hydrogenolysis of spruce wood lignin over a rhodium-on-charcoal catalyst has been studied and monitored by the yields of the three major degradation products, 1, 2, and 5. Variables included: initial pressure of hydrogen, amount of catalyst, and acidity–basicity of the media. Little variation occurred under moderate acidic or basic conditions with yields of 18–20% of lignin recovered as monomers. Under strongly acidic or basic conditions both yields and relative abundances changed appreciably. Initial hydrogen pressures less than 500 psig resulted in slightly decreased yields in some cases. In strongly alkaline media similar results were obtained with or without added hydrogen provided the catalyst were present.

Studies on Lignin and Related Compounds. XXXV. The Ethanolysis of Spruce Wood

1939 ◽  
Vol 61 (2) ◽  
pp. 509-516 ◽  
Author(s):  
A. B. Cramer ◽  
M. J. Hunter ◽  
Harold. Hibbert
Keyword(s):  
Spruce Wood ◽  
Related Compounds

A STUDY CONCERNING THE KINETICS OF THE SULPHITE PROCESS

1936 ◽  
Vol 14b (9) ◽  
pp. 336-345
Author(s):  
A. J. Corey ◽  
O. Maass
Keyword(s):  
Wood Chips ◽  
Wood Meal ◽  
Spruce Wood ◽  
Controlled Conditions ◽  
Kinetics Of

Delignification rates of spruce wood chips and wood-meal have been investigated under carefully controlled conditions at temperatures ranging from 100° to 140 °C. The rates are shown to be in only approximate agreement with the monomolecular law, but the change in the rate of delignification with temperature obeys the equation of Arrhenius.

THE EFFECT OF MAGNESIUM-BASE SULPHITE-LIQUOR COMPOSITION ON THE RATE OF DELIGNIFICATION OF SPRUCE WOOD AND YIELD OF PULP

1938 ◽  
Vol 16b (7) ◽  
pp. 242-252
Author(s):  
J. M. Calhoun ◽  
J. J. R. Cannon ◽  
F. H. Yorston ◽  
O. Maass
Keyword(s):  
Sulphur Dioxide ◽  
Lignin Content ◽  
Simple Equation ◽  
Type Formula ◽  
Wood Meal ◽  
Spruce Wood ◽  
Rate Of Reaction ◽  
Mole Percentage ◽  
Free Sulphur

The rate of delignification of resin extracted spruce wood-meal in magnesium base sulphite liquor has been determined at 130 °C. over the concentration range 0.5 to 4% combined, and 2 to 10% free, sulphur dioxide. The rate of reaction is roughly proportional to the concentration of free sulphur dioxide when the combined is constant, but decreases with increase in the concentration of combined when the free is constant. The relation of the rate of delignification to the liquor composition cannot be expressed by any simple equation of the type:[Formula: see text]where K and n are constants. The rate of cooking is somewhat greater in magnesium base sulphite liquor than in calcium base liquor of the same mole percentage composition.The yield of pulp at any given lignin content is independent of the free sulphur dioxide over the whole concentration range, but increases with increase in the concentration of the combined to a maximum at about 3%, and decreases at slightly higher concentrations. When the concentration of combined sulphur dioxide is greater than 1% the yield of pulp obtained from magnesium base cooks is slightly higher than that from corresponding calcium base cooks.

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