Lignin Propyl

Lignans are phenylpropanoid dimers in which the monomers are linked by the central carbon (C8) atoms of the propyl side chains (Fig. 12.1) [10]. Many lignans are formed from coniferyl alcohol, a typical lignin monomer, and the coupling of two coniferyl alcohol radicals proceeds under the control of a unique asymmetric... 

Chain extension with PO Partially blocked hydroxypropyl lignin derivatives were reacted with propylene oxide in toluene, using KOH as catalyst, for the purpose of creating extended propyl ether chains. This has been reported elsewhere (13). 

Hydroxy propyl lignin (HPL) Two different HPL preparations were used in this study (12). Blends containing PE and EVA utilized an HPL from organosolv (methanol) lignin from red oak and blends containing PVA and PMMA utilized an HPL from kraft lignin (Indulin-AT from Westvaco Corporation, Charleston, SC). 

CIEMNIBCKI GLASSER Polymer Blends with Hydroxy propyl Lignin 463... 

The apparent yields of monophenol ranged from 15% at 370°C. to 44% at 430°C. Neither the phenol nor the green lignin tar used for pasting oil could be completely recovered, and losses of 20-30% of the pasting oil were noted. Large, pitchy, nondistillable residues were obtained. In addition to the monophenols previously determined by the Noguchi Institute, we confirmed the presence of 0-ethylphenol, 0-w-propyl-phenol, 2,4-xylenol and 2,6-xylenol. 

Although in many of the reports lignin products of either a cyclohexyl or phenyl nucleus with one, two, or no carbon side chains attached have been reported, the greater abundance (under nonalkaline conditions) of the propyl side chain must be regarded as evidence for the essentially C6-C-C-C nature of a unit of the lignin substance. 

A third dimer was obtained from Norway sprucewood in somewhat impure condition (m.p., 117°-127°C.). However, its vapor phase retention time and ultraviolet spectrum 23) were identical with those of authentic 5,5 -diethyl-2,2 -dihydroxy-3,3 -dimethoxybiphenyl (VII), m.p. = 143°C. (P). Furthermore, the NMR spectrum and melting point of its purified diacetate were identical with those of the synthetic compound. The corresponding 5,5 -di-w-propyl derivative has already been isolated from neutral hydrogenation of softwood lignin in our laboratory 18). 

When considering biomass as a source of chemical feedstock, it is also important to remember that it is not a homogeneous organic structure. The carbohydrate structures of terrestrial plants are composed of both five-carbon and six-carbon sugar polymers. The lignin component, which binds the polymers together, is an aromatic polymer of nominally propyl-methoxyphenols. In addition, there are proteins and fatty acids/oils, as well as the trace biocomponents that incorporate much of the mineral content. Therefore, processing biomass to chemical products must take into consideration both its bulk chemical structure and its components. 

In bonding wood, the reaction of isocyanate groups with the numerous hydroxyl groups that are present in the various components of wood—cellulose, hemicellulose, and lignin—is possible. The product of this chemical reaction with wood is the urethane bond as shown in Reaction I. Methyl, ethyl, propyl, and butyl isocyanates... 

E J Siochi, M A Haney, W Mahn, T C Ward. Molecular weight determination of hydroxy-propylated lignins In W G Glasser, S Sarkanen, eds. Lignin, Properties and Materials. Washington, DC Am Chem Soc, 1989, pp. 100-108. 

The predominant aliphatic units in type III kerogen are small chains (mostly methyl and propyl), primarily derived from lignin residues in vitrinite macerals, and so hydrocarbon gases, particularly methane, are the main petroleum products. There may be some potential for oil production if cutan and/or suberan has been incorporated into the kerogen. Similarly, there is now... 

Bonding methyl, ethyl, propyl, and butyl isocyanates to wood gives good decay resistance at weight gains above about 20%. Determination of the distribution of bonded chemical with methyl isocyanate in southern pine shows that 60% of the lignin hydroxyls are substituted and 12% of the holocellulose hydroxyls are substituted at the point where resistance to biological attack occurs. 

The experimental studies on the phenolic lignin model compounds (4-propyl-guaiacol, eugenol, isoeugenol, coniferyl alcohol, coniferyl aldehyde and 4-allyl-2,6-dimethoxyphenol) demonstrated that these compounds had more active antioxidants activity than the commercial inhibitor (2,6-di-tert-butyl-4-methyl-phenol) BHT during peroxidation of styrene in chlorobenzene initiated by... 

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