Phenylpropane monomers

Lignin in the true middle lamella of wood is a random three-dimensional network polymer comprised of phenylpropane monomers linked together in different ways. Lignin in the secondary wall is a nonrandom two-dimensional network polymer. The chemical structure of the monomers and linkages which constitute these networks differ in different morphological regions (middle lamella vs. secondary wall), different types of cell (vessels vs. fibers), and different types of wood (softwoods vs. hardwoods). When wood is delignified, the properties of the macromolecules made soluble reflect the properties of the network from which they are derived. 

To our knowledge, the coumarone ketol (XXII) is the first crystalline dimeric lignin degradation product with two complete phenylpropane skeletons which has been reported in the literature 26). On the basis of the model experiments discussed above, the presence of the ketol side chain as well as the phenylcoumarone system in (XXII) indicates that the origin of the product is a sequence of three phenylpropane monomers (XXVIII) in lignin, involving a phenylcoumaran system carrying a gly-... 

As we know that phenol-formaldehyde (PF) resins were the first completely synthetic commercial polymer. Lignin constituted hy structure of three primary phenylpropane monomers can replace phenolic compounds in the synthesis of phenol-formaldehyde (PF) resins. Besides its use in polyurethanes and polyesters, technical lignins are also of interest in phenolic and epo Q resins. Kraft lignin can be used to displace up to 70% of the phenol required for PF resins, which can greatly decrease the raw material consumption. 

Whereas two-thirds of wood consists of polysaccharides, one-third of wood consists of lignin, a phenylpropane polymer formed via the shikimic acid pathway. Therefore, it is perhaps not surprising that wood extractives are extraordinarily rich in a wide array of benzenoid natural products, many of which are derived from the same phenylpropane monomers. 

For evaluating the influence of CD on the photoinitiated polymerization process, the polymerization of a water soluble monomer, AMsopropylacrylamide (NIPAAM), using complex of Me-P-CD and 2-hydroxy-2-methyl-1-phenylpropan-l-one (13) as... 

Yield of the main monomer(s) on thioacidolysis of spmce, birch and aspen wood, spruce TMP and the corresponding MWLs together with the number of phenolic hydroxyl groups per 100 phenylpropane (C9) units [20, 23]... 

One example of UV nanoimprint resists is shown in Figure 4.9. The resin contains three kinds of acryl monomers t-butylacrylate, ethylene glycoldiac-rylate, and (3-acryloxypropyltristrimethylsiloxy)silane. The resist also contains a photoinitiator, 2-hydroxy-2-methyl-l-phenylpropane-l-on. The resin... 

The following reactions of olefins have also been studied formation of dialkyl adducts (517) from vinyl monomers and dienes with lithium metal and alkyl bromides in THF alkylsulphonium salts (518) from thioethers and protonated alkenes hydroformylation of styrene and a-methylstyrene in the presence of bis-(iV-a-methylbenzylsalicylaldiminato)cobalt(n) to give 2-phenylpropanal (optical purity 1.9%) and 3-phenylbutanal (optical purity 2.9%) various electron-rich olefins of the type (519) with primary amines... 

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