Lignin, thermal decomposition

Ramiah, M.V. and Goring, D.A.I. (1967). Some dilatomeric measurements of the thermal decomposition of cellulose, hemicellulose and lignin. Cellulose Chemistry and Technology, 1(3), 277-285. 

Burton, H.R. Thermal decomposition and gas phase analysis of carbohydrates found in tobacco in Thermal uses and properties of carbohydrates and lignins, edited by F. Shafizadeh, K.V. Sarkanen, and D.A. Tillman, Academic Press, New York, NY (1976) 257-310. 

Kato, K., F. Sakai, and T. Nakahata Thermal decomposition of tobacco lignin Sci. Papers, Cent. Res. Inst., Japan Monopoly Corp. 107 (1965) 171-175. 

Thermal decomposition, viz. dehydrochlorination of PVC, unzipping of PMMA or POM, ester-group decomposition, carbonization of lignin, etc. 

A great amount of insight can be obtained by the computational smdy of the thermal decomposition of /3-0-4 model compounds, representing the most common linkage in lignin. While experimental work determines overall product distributions and total rates of reaction [33,37], kinetic parameters of individual reactions and details of substiment effects on equilibrium and transition state structures are difficult to obtain... 

Figure 6.7 presents TGA curves of polyurethane, cellulose, lignin and composites reinforced with cellulose and lignin. The decomposition of the polyurethane takes place in one step, while the composites decompose in two steps. In the first stage, decomposition occurs after the decomposition of the fiber and matrix alone. The small weight loss up to 100°C is related to the moisture content of the material. Above this temperature, some water molecules that are tightly bound to the fibers become volatile [21]. Thus, reinforcement decreases the thermal stability of the composite. 

More work was carried out to study the effect of wood, cellulose, lignin, and activated charcoal on the thermal decomposition of polystyrene (PS) and polyethylaie (PE) occurring in municipal waste. Py-GC/MS revealed that these materials had a similar influence on PS and PE thermal decomposition under slow and fast heating conditions. The effect is related to the char-forming capability of the wood-derived additives thus cellulose had the least and pure charcoal had die greatest influence on the decomposition of the polymers studied. The yield of monomers, dimers, and trimers decreased, and the formation of other products (e.g., toluene, ethyl benzene, and a-methyl styrene) was detected in the obtained pyrograms. 

As it can be observed, the thermal decomposition for the starch-lignin based fillers composite materials can be divided into three individual stages moisture... 

WF decompose, both materials emit oxide gases and radicals, which initiate the degradation of PLA to break down the chain. PLA blended with WF is more resistant to decomposition due to the complex lignin structure, which acts as a hydrophobic shield protecting the PLA chains from direct attack of the volatiles. This observation can be further justified by the work of Tao et al. (2009) who compared PLA blended with jute and ramie fibers they found that there was a lack of significant difference in thermal decomposition for both natural fibers (see Figure 3.13). 

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