Lignin studies

Akiyama, T. Magara, K. Matsumoto, Y. Meshitsuka, G. Ishizu, A. Lundquist, K. Proof of the presence of racemic forms of arylglycerol-p-aryl ether structure in lignin studies on the stereo structure of lignin by ozonation. J. Wood Sci. 2000, 46, 414-4-15. 

Gierer, J., Yang, E. and Reitberger, T. (1992). The reactions of hydroxyl radicals with aromatic rings in lignins, studied with creosol and 4-methylveratrol. Holzforschung, 46(6), 495-504. 

Table I illustrates the molecular weight averages found from universal calibration (narrow standards) for four aspen lignins and two quinonemethide-derived polymers using the Unical software. The poly-dispersities were the same within the experimental errors for all lignin samples. In contrast, the polydispersities found for the quinonemethide-derived polymers by universal calibration were near 1.1. The molecular weight averages found for the four acetylated lignins studied by universal calibration were substantially larger than those determined from previous work using conventional GPC (e.g., AESE and BM lignins from refs. 7 and 12 had approximately one-third those values found by HPSEC-DV in the present study).

Table II gives a number of derived parameters used to assess the lignin s suitability as a binder. For a full binder, lignins required a minimum of three sites per average molecule for formaldehyde grafting. None of the lignins studied approach this level. At least twice the number of sites found is required for steam exploded lignins and more for the kraft lignin. PF resins have an average of eight sites per molecule, a much higher density than projected, so PF resins are excellent wood binders.

Oxidation of Alkali Lignin Studies on Oxidation in Alkaline Solution... 

Encouraged by the success of the hydrogenolysis of aspenwood meal this approach to lignin study w.as continued in these laboratories. Special attention was given to the effect of adding acid or base and to the use of palladium-charcoal as a catalyst on the products of hydrogenation of both aspen- and sprucewood meals. 

With the database of cross-coupling products from the synthetic lignin studies, researchers attempted to look for these components in real lignins. Unfortunately, the... 

J Sealey, AJ Ragauskas. Residual lignin studies of laccase-dehgnified kraft pulps. Enzyme Microb. Technol. 23(7-8) 422-426, 1998. 

Jakab, E Faix, 0 and Till, F. (1997). Thermal decermposition of milled wood lignins studied by thermogravimetry/mass spectroscopy. /. Anal. Appl. Pyroly. 40-41, 171 - 186. 

Recently, data regarding the lignin study both in the solid state and solution with the modem and performance techniques, namely the small-angle X-ray scattering (SAXS) and ultra-smaU-angle X-ray scattering (USAXS) [166], pulsed field gradient spin-echo NMR [167, 168], nano zeta sizer techniques [169] have been reported. 

As only lignins of low molecular weight are studied, dimers and trimers have exclusively been found in the composition of the four lignins studied. However, it is not necessary to calculate the theoretical interaction energy with cellulose for... 

Hirose S, Kobashigawa K, Izuta Y, Hatakeyama H (1998) Thermal degradation of polyurethanes containing lignin studied by TG-FTIR. Polym Int 47 247-256... 

Nakamura T, Kawamoto H, Saka S. Pyrolysis behavior of Japanese cedar wood lignin studied with various model dimers. J Anal Appl Pyrol. 2008 81(2) 173—182. 

Custodis VBF, Hemberger P, Van Bokhoven JA. Mechanism of fast pyrolysis of lignin studying model compounds. J Phys Chem B. 2014 118 8524-8531. 

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