Lignins monomer composition

Table II. Lignin Monomer Composition, Obtained by Nitrobenzene Oxidation of Lignin from Normal and Brittle Fescue Grown at Lusignan (Same as in Table I)...

Meyer, K., Shirley, A. M., Cusumano, J. C., Bell-Lelong, D. A., and Chappie, C., 1998, Lignin monomer composition is determined by the expression of a cytochrome P450-dependent monooxygenase in Arabidopsis, Proc. Natl. Acad. Sci. USA 95 6619-6623. 

Lignin monomer composition is determined by the expression of a cytochrome P450-dependent monooxygenase in Proc. Natl. Acad. Sci. 95(12), 6619-6623. 

K Meyer, AM Shirley, JC Cusumano, DA Bell-Lelong, C Chappie. Lignin Monomer Composition Is Determined by the Expression of a Cytochrome P450-dependent Monooxygen se in Arabidopsis. Proc Natl Acad Sci USA 95 6619, 1998. 

In this work, our main objective was to explore the underlying reasons for such variations in graminaceous lignins. As before for rice (26), phenolic-ester and lignin analyses (content and monomer composition) were carried out, although only lignin data are shown here. 

Secondly, a biosynthetic investigation on lignin variation was undertaken using maize internodes. Maize internodes were examined in this study since (a) fewer plants were required for analysis (greater biomass) and (b) possible variations between normal and b.m-mutants (21) could be studied. Lignin contents and monomer composition were compared between internodes, both being collected at the top and the bottom of the maize stem. These plant parts were chosen because of differences in the digestibility of different internodes as documented for Timothy (Phleum pratense)... 

Tables IV and V show the monomer composition of lignins for both parietal and saponification residues. In this regard, comparison between PR and SR values allows the characterization of the lignin core, which is not solubilized after alkaline treatment (20,21). Instead of using nitrobenzene oxidation, thioacidolysis was used to characterize the non-condensed...

Studies by Bolker and Brenner [29] were also based on statistical methods. According to the theoretical notions of the authors, MMD of native lignin depends on the composition of lignin monomeric precursors. To find this quantity, one has to list all probable ways by which the molecular tree with a specified number of junctions and monomer compositions may be drawn. MMD of isolated lignin, i.e., sol, is defined by decomposition velocity of simple ether bonds. This problem was solved by Bolker for a particular case of a crosslinked system in which only the scission of crosslinkages formed by benzylether bond takes place. 

These polysaccharides are one of the renewable resources that are most widely found in nature. These polymers present in plants together with cellulose and lignin. Hemicellulose is different from other celluloses in terms of the monomer composition, and has a long chain and molecular chain branching. The content of these compounds differ from species to species [9,10]. 

A polymeric composition for reducing fluid loss in drilling muds and well cement compositions is obtained by the free radical-initiated polymerization of a water-soluble vinyl monomer in an aqueous suspension of lignin, modified lignins, lignite, brown coal, and modified brown coal [705,1847]. The vinyl monomers can be methacrylic acid, methacrylamide, hydroxyethyl acrylate, hydroxypropyl acrylate, vinylacetate, methyl vinyl ether, ethyl vinyl ether, N-methylmethacrylamide, N,N-dimethylmethacrylamide, vinyl sulfonate, and additional AMPS. In this process a grafting process to the coals by chain transfer may occur. 

The composition, reaction conditions, and yield of copolymer-1 (24-37 series ) are shown in Table 12. The content of 4N,4N-dimethyl-4-ammoniumhept-1,6-diene chloride in the reaction ranges from 0 to 30 molar percent of total monomer content. The concentration of lignin, calcium chloride, and monomer in the... 

In reactions with ethenylbenzene, lignin was used to make thermoplastic materials. Data for a spectrum of reactions run to optimize yield and create samples of different molecular weights and composition [53] are given in Table 7. Samples PE-1 to PE-10 were made with ethenylbenzene as monomer. These products have been shown to be polylignin- -(l-phenylethylene)-con-taining materials by a series of solubility and extraction tests and are formed... 

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