Synthesis from lignin

By far the preponderance of the 3400 kt of current worldwide phenolic resin production is in the form of phenol-formaldehyde (PF) reaction products. Phenol and formaldehyde are currently two of the most available monomers on earth. About 6000 kt of phenol and 10,000 kt of formaldehyde (100% basis) were produced in 1998 [55,56]. The organic raw materials for synthesis of phenol and formaldehyde are cumene (derived from benzene and propylene) and methanol, respectively. These materials are, in turn, obtained from petroleum and natural gas at relatively low cost ([57], pp. 10-26 [58], pp. 1-30). Cost is one of the most important advantages of phenolics in most applications. It is critical to the acceptance of phenolics for wood panel manufacture. With the exception of urea-formaldehyde resins, PF resins are the lowest cost thermosetting resins available. In addition to its synthesis from low cost monomers, phenolic resin costs are often further reduced by extension with fillers such as clays, chalk, rags, wood flours, nutshell flours, grain flours, starches, lignins, tannins, and various other low eost materials. Often these fillers and extenders improve the performance of the phenolic for a particular use while reducing cost. 

For example, vanillin can be obtained via at least five different ways (i) by isolation from the orchid (Vanilla planifolia), which is a very expensive method (ii) by tissue culture followed by extraction (iii) by microbial transformation of eugenol, the main compound of clove (iv) from lignine by synthesis, and (v) from guaiacol, a natural aroma compound, with comparable molecular structure. Only the vanillin obtained via the first three methods is natural. The other routes afford a nature-identical vanillin. 

Wegenmayer, H., Ebel, J. and Grisebach, H., 1976, Enzymic synthesis of lignin precursors Purification and properties of a cinnamoyl-CoA NADPH reductase from cell suspension cultures of soybean (Glycine max L.), Eur. J. Biochem. 65 529-536. 

The synthesis of lignin from phenylalanine in plants involves two successive (and... 

Newman, W. H. Glasser, W. G. Engineering plastics from lignin. 12 Synthesis and performance of lignin adhesives with Isoxyanate and Melamine. Holzforschung 1985, 39,(6) 345. 

Ahammed, S. Prema, P. (2002). Influence of media on synthesis of lignin peroxidase from Aspergillus sp. Applied Biochemistry and Biotechnology, 102, 327-36. 

Hofmann K, Glasser WG (1993) Engineering plastics from lignin. 21. Synthesis and properties of epoxidized Ugnin-poly(propylene oxide) copolymers. J Wood Chem Technol 13 73-95... 

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