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: XIII. THE STRUCTURE AND PROPERTIES OF GLYCOL LIGNIN

1935 ◽  
Vol 13b (1) ◽  
pp. 35-47 ◽  
Author(s):  
K. R. Gray ◽  
E. G. King ◽  
Fritz Brauns ◽  
Harold Hibbert
Keyword(s):  
Chemical Composition ◽  
Ethylene Glycol ◽  
Soluble Fraction ◽  
Primary Alcohol ◽  
Hydriodic Acid ◽  
Structure And Properties ◽  
Spruce Wood ◽  
Derivatives Of ◽  
Related Compounds ◽  
Soluble Lignin

Lignin was extracted from spruce wood meal with ethylene glycol containing (a) 0.05% and (b) 0.2% hydrogen chloride. On purification the two glycol lignins were found to contain 16.9% OCH3 and 62.8% C., and 16.5% OCH3 and 64.7% C. respectively. The aqueous glycol mother liquor was found to contain a soluble lignin-carbohydrate compound. The glycol lignin could be separated into a chloroform-insoluble and a chloroform-soluble fraction, each having the same chemical composition and yielding the same methylated products. From the glycol lignin, purified by means of dioxane-ether, acetylated and methylated derivatives were prepared, as were also trityl derivatives of glycol lignin and premethylated glycol lignin.The introduction of three trityl groups indicates the presence of three primary alcohol groups in the original lignin. Glycol lignin can be both partially and completely demethylated by use of hydriodic acid. The effect of the glycol radical on the methoxyl value in the Zeisel determination was studied and an equation derived for the correction of the methoxyl value. The bearing of the results on the formula proposed previously (1) for methanol lignin is discussed.

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: I. A NEW METHOD FOR THE ISOLATION OF SPRUCE WOOD LIGNIN

1930 ◽  
Vol 2 (6) ◽  
pp. 357-363 ◽  
Author(s):  
Harold Hibbert ◽  
H. J. Rowley
Keyword(s):  
Hydrochloric Acid ◽  
Ethylene Glycol ◽  
Ethyl Ether ◽  
Cold Water ◽  
New Method ◽  
Large Excess ◽  
Spruce Wood ◽  
Hydroxy Compounds ◽  
Related Compounds ◽  
Unchanged Form

A description is given of a new method for the isolation from spruce meal of lignin in apparently a relatively unchanged form. The method consists in first extracting the spruce meal with a mixture of equal volumes of benzene and alcohol, followed by an extraction with water. The dried meal is then digested for 6–8 hr. at 110 °C. with 8–10 times its weight of ethylene glycol containing 0.2% of iodine, calculated on the weight of spruce meal taken. The reaction mixture is filtered, and the lignin isolated by pouring the filtrate into a large excess of cold water. Other catalysts such as hydrochloric acid may be used in place of iodine and the glycol may be replaced by a variety of hydroxy-compounds such as glycol mono-ethyl ether, glycerol, chlorhydrins, hydroxyacids, etc.

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.

scholarly journals Sigmoidal Dependence of Electrical Conductivity of Thin PEDOT:PSS Films on Concentration of Linear Glycols as a Processing Additive

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1975
Author(s):  
Hyeok Jo Jeong ◽  
Hong Jang ◽  
Taemin Kim ◽  
Taeshik Earmme ◽  
Felix Sunjoo Kim
Keyword(s):  
Electrical Conductivity ◽  
Ethylene Glycol ◽  
Triethylene Glycol ◽  
Optical Transmittance ◽  
Monomethyl Ether ◽  
Additive Concentration ◽  
Transparent Electrodes ◽  
Ethylene Glycol Monomethyl Ether ◽  
Conductivity Enhancement ◽  
Poly Styrene Sulfonate

We investigate the sigmoidal concentration dependence of electrical conductivity of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) processed with linear glycol-based additives such as ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), hexaethylene glycol (HEG), and ethylene glycol monomethyl ether (EGME). We observe that a sharp transition of conductivity occurs at the additive concentration of ~0.6 wt.%. EG, DEG, and TEG are effective in conductivity enhancement, showing the saturation conductivities of 271.8, 325.4, and 326.2 S/cm, respectively. Optical transmittance and photoelectron spectroscopic features are rather invariant when the glycols are used as an additive. Two different figures of merit, calculated from both sheet resistance and optical transmittance to describe the performance of the transparent electrodes, indicate that both DEG and TEG are two most effective additives among the series in fabrication of transparent electrodes based on PEDOT:PSS films with a thickness of ~50–60 nm.

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.

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