Sulfate lignin

By means of Fremy salt oxidation, Adler and Lundquist (5) estimated that about half of the phenolic units contain free S-positions in M.W.L. Mikawa (J/), by Mannich reaction, obtained evidence that about 25-40% of the phenolic units in his sulfate lignin preparation contained no substituent in 5-position. In this investigation we also conclude that at least one-third of the phenolic units in our kraft lignin preparation has free 5-positions. 

Sulfate lignin was extensively degraded by treatment with unstabilized peroxide at pH 11 and 100°C [66]. 

Alkali lignin, which is prepared by treating the wood with aqueous solutions of sodium hydroxide, in the presence of sodium sulfide (sulfate lignin) is a more appropriate object for structural studies. This polymer is not a polyelectrolyte and has a high molecular mass. In dimethylsulfoxide (DMSO), the macromolecules of sulfate lignin are compact particles, which are characterised by [r ] varying from 7.4 (M = 1.3 x 10 ) to 13.3 cm /g (M = 38.7 X 10 ) and the log [p] versus log M plot with the slope b = 0.15 [45, 46]. 

In another work, [177] described the particle-size distribution of sulfate lignin based on thermodynamic model. This model suggests the formation of steady-state microstructure by aggregation of primary lignin particle into metastable clusters (aggregates) closely packed. The distribution of the statistical ensembles of particles is broadened and their average size increase with temperature due to the thermal coagulation process. 

Lennox Polymers LTD USA Sulfate lignin (Lenox lignin) Formaldehyde-free resins Adhesives for wood products (chips, laminates, veneers) High-performance specialty resins urethane and polyester molding resins, thermoplastic resins Traction products winter tire traction product Lubricants... 

Yu, E., Dem yantseva, N.P., Lysogorskaya, V.V., Klyubin, S., Zaitseva, V. A dynamic light scattering study of the temperature dependence of the size-distribution pattern and aggregation stabihty of sulfate lignin and wood resin in aqueous alkali solution. Russ. J. Appl. Chem. 75(1), 149-15 (2002)... 

A. Raghuraman, V. Tiwari, Q. Zhao, D. Shukla, A.K. Debnath, and U.R. Desai, Viral inhibition studies on sulfated lignin, a chemically modified biopolymer and a potential mimic of heparan sulfate, Biomacromolecules, 8 (5), 1759-1763,2007. 

Polypropylene has also been modified by extrusion at 220°C in the presence of alkaline sulfate lignin and a plasticizer [140]. The significant modifying effect of the lignin appears to result from its rupture into free radicals, which may cause polypropylene cross-hnking. The modified polypropylene (called Propolin) is used to make films that have increased low-temperature and light resistance. 

Manufacturing procedures for producing dye dispersions are generally not disclosed. The principal dispersants in use include long-chain alkyl sulfates, alkaryl sulfonates, fatty amine—ethylene oxide condensates, fatty alcohol—ethylene oxide condensates, naphthalene—formaldehyde—sulfuric acid condensates, and the lignin sulfonic acids. 

During the first trials with synthetic separators around 1940 it had already been observed that some of the desired battery characteristics were affected detrimentally. The cold crank performance decreased and there was a tendency towards increased sulfation and thus shorter battery life. In extended test series, these effects could be traced back to the complete lack of wooden lignin, which had leached from the wooden veneer and interacted with the crystallization process at the negative electrode. By a dedicated addition of lignin sulfonates — so called organic expanders -— to the negative mass, not only were these disadvantages removed, but an improvement in performance was even achieved. 

Gierer, J. Ljunggren, S. The reactions of lignin during sulfate pulping. Part 17. Kinetic treatment of the formation and competing reactions of quinone methide intermediates. Sven. Papperstidn. 1979, 82, 503-512. 

Repeated methylation of bagasse native lignin with dimethyl sulfate yielded a product with a 29-1 % methoxyl content. Four such methyl-ations did not change this value. However, the infrared spectrum of this derivative still revealed a small absorption band at 3400 cm1. Thus, it appeared that at least one hydroxyl group could not be methylated. Treatment of this methylated product with acetic anhydride and pyridine gave an acetate, which did not exhibit an absorption band at 3400 cm-1. Consequently, a tertiary hydroxyl group, which can be acetylated but not methylated, seems to be present in this lignin. 

Urban (116), found that completely methylated cellulose was soluble in chloroform, whereas methylated lignin was insoluble in this solvent. Therefore, he reacted the wood with dimethyl sulfate until methylation was complete. On extraction of this wood with chloroform, both the methyl lignin and methylcellulose were dissolved without being separated. 

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