Production lignin-based

Even the outstanding mechanical properties of natural products are based on the principle of polymer blends, like, for example, wood, which is composed in a complicated way of cellulose and lignin. 

Lignin utilization studies have been conducted in several fields. However, no practical, commercial process has yet emerged for the manufacture of lignin-based polymeric materials. This is undoubtedly related to such factors as product inhomogeneity, reactivity differences, and also with lack of familiarity with this type of raw material. It should be also stressed that lignins are only by-products from pulp manufacture. However, the utilization of lignins in polymeric materials seems to be possible. 

Cure Rate of the Phenolated SEL Resins. 13C NMR spectra of the phenolated SEL formaldehyde-treated resins revealed the formation of methylol groups. A similar cure reaction to resole type phenolic resins is expected to occur with the phenolated lignin-based resins. Since cure rate normally determines production capacity of a board mill, it is important that new types of adhesives have at least the same cure rate as the conventional phenolic adhesives. Cure analysis of resins has usually been examined by... 

Another category of lignin-based chemicals is obtained when lignosulfonates are degraded to low molecular weight products. The commercially most important product is vanillin, which is obtained by alkaline oxidation... 

The structures of the lignins are amenable to conversion to several classes of substituted phenols by thermochemical and thermal degradation methods. The displacement of pyroligneous tars by coal tars eliminated much of the demand that existed for the lignin-based products. Creosote oil or cresylic acid, a mixture of o-, m-, and p-cresols, is now manufactured mainly from coal tars, while only small amounts of cresols are made from wood tars. The use of wood tars and other biomass-derived tars as substitutes for a major portion of the phenol and formaldehyde in phenol-formaldehyde resins could reverse this trend (Himmelblau, 1995). The key to this process seems to be that the... 

Adhesive properties are listed in Table IX. Shear strength, wood failure, and swelling data for two wood species, southern pine and hard maple, illustrate excellent performance properties of lignin-based urethane products. 

Pulp and paper industry is quite relevant to Chilean economy. Kraft process for cellulose production is based on the chemical digestion of wood chips with sodium hydroxide and sodium sulfide at high pressure to extract the lignin and recover the... 

Based on Uterature [205] information we can appreciate that the potential lignin-based products were divided into the following three directions ... 

Lignin is part of the composition of natural polymers in variable proportions. The aromatic structure of the lignin can be used as source of several phenolic products, which may substitute petroleum-based compounds. Bio-based composites have gained prominence over the past two decades owing to both environmental concerns and waste disposal problems. Lignin-based biomaterials include carbon fibers, polymer modifiers, resin/adhesives/binders and others. 

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