Effects of Lignin

TABLE 3.2 A typical chemical composition of hardwoods, softwoods, and rice hulls 

Lignin generally makes the product weaker, because it easily burns in the course of processing and releases CO2, making the product density lower, and greatly accelerates fading of the WPC after outdoor exposure. 

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Figure 3.5 The effect of lignin removal upon reactivity of acetic anhydride with MDF fibre (a) (from data of Hague and ffill, 2000) and wood flour (b) (from data of ( etin, 1999).

We have shown that TDCSPPFeCl (HI) is so far the most stable and efficient catalyst among the iron porphyrins used as model ligninases. All the known reactions catalyzed by this porphyrin mimic the ligninases quite well. TDCSPPFeCl can be used in both aqueous and polar organic solvent (such as methanol, DMF) so that solvent effects of lignin degradation can be studied. The catalyst is stable over a wide range of pH so the reactions at different pH can be compared. 

Table IV. Technological and Mechanical Properties of Biobonded Particle Boards Effect of Lignin Type, Enzyme Activity and Pressing Time...

Figure 1. Effect of lignin content on the glass transition temperature (Ta) of networks crosslinked with HDI. Formulation type A ( ) type B ( ) and type C (0).

Discussion. The overall effect of lignin hydroxy content on the interaction with HPC is illustrated in Figure 4. As the hydroxy content is reduced, the interaction energy increases until a maximum is reached at a DS of ca. 

Figure 5. Effect of lignin content on mechanical properties of HPC/OSL blends prepared by injection molding (—), dioxane casting (—), and pyridine casting (— —).

Lignin Styrene Ozonization avoids inhibiting effect of lignin on styrene polymerization [196]... 

Straforelli (2) investigated the effect of lignin on the graft copolymerization of methyl methacrylate initiated by azo-... 

Effect of Lignin on Grafting Efficiency, Conversion and Polymer Loading. ... 

In this entry, the effect of blending recyclable poly-(propylene) (PP) and poly(ethylene terephthalate) (PET) with lignin on carbon fiber production is presented. We discuss the effects of lignin structure and specific intermolecular interactions on lignin thermal properties as well as the effect of blend composition on surface morphology, mechanical properties, and the manufacturing process of lignin/recyclable plastic-based carbon fibers. 

It is apparent from the data in Table III that the effects of lignin are restricted to the cellulose and hemicellulose carbohydrates of the plant cell wall. One must reject the conclusion of Drapala (23) that availability of cellular contents is lowered by entrapment in lignified cells. 

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