Degradation mechanisms lignocellulose

Keywords-, lignocellulosic fibers, kinetics, degradation mechanism, thermal decomposition, reaction models. 

Analysis of the effect of cellulose derivatives on PP, PS and PE thermal degradation showed that the presence of cellulosic materials produced a slight increase in the degradation temperature associated with a change in the degradation mechanism of PP. The yield of monomer and trimer from the thermal decomposition of PS was reduced in the presence of cellulose derivatives, indicating that radical chain reactions are hindered by the presence of lignocellulosic char. On the other hand, the effect of PP on the thermal decomposition... 

The temperature often determines the shape of action or activation spectra where both thermal and photochemical processes produce the same outcome. Both lignocellulose and poly(vinyl chloride), for instance, yellow on exposure to UV radiation as well as on heating. In the case of the latter substrate, even the mechanism of yellowing is the same. It is, therefore, necessary to include adequate controls in the experiments to estimate the relative importance of thermal processes in those exposures that cause combined photo-thermal degradation. Alternatively, additional samples might be exposed behind filters with... 

As mentioned previously, the main bottleneck in the broad use of these fibers in thermoplastics is the poor compatibility between the fibers and the matrix. The inherent high moisture sorption of lignocellulosic fibers certainly has an effect on their dimensional stability [28]. This may lead to the microcracking of the composites and degradation of mechanical properties [28]. Like other natural fibers, kenaf absorbs moisture due to its hydrophilicity. The key issue related to the development and production of natural fiber-reinforced composites is the interfacial adhesion between the fiber and polymer matrix. Because of their inherent dissimilarities, natural fibers/polymer matrix composites are not compatible and interfadal adhesion in these composites tends to be poor. The weak bonding at the interfaces between natural fibers and polymer matrix is surely a critical cause of the reduction of useful properties and performance of the... 

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