Cellulose fibers chemical behavior

Much of the chemical behavior of cellulose fiber can be attributed to cellulose structure. Since cellulose is a highly crystalline polymer, it can absorb mechanical energy efficiently for mechanical stress reaction ( 5, 19). The mechanically activated thermal energy, in addition to rupture of main chains, may alter morphology or microstructure of cotton cellulose. Accordingly, the crystallinity and accessibility of cotton fiber may be influenced. 

It has been observed from the above discussion that mechanical, physico-chemical and fire retardancy properties of UPE matrix increases considerably on reinforcement with surface-modified natural cellulosic fibers. The benzoylated fibers-reinforced composite materials have been found to have the best mechanical and physico-chemical properties, followed by mercerized and raw Grewia optiva fibers-reinforced composites. From the above data it is also clear that polymer composites reinforced with 30% fibers loading showed the best mechanical properties. Further, benzoylated fibers-reinforced composites were also found to have better fire retardancy properties than mercerized and raw fibers-reinforced polymer composites. Fire retardancy behavior of raw and surface-modified Grewia optiva/GPE composites have been found to increase when fire retardants were used in combination with fibers. This increase in fire retardancy behavior of resulted composites was attributed to the higher thermal stability of magnesium hydroxide/zinc borate. 

Wan WK, Hotter JL, Millon LE, Guhados G (2006) Bacterial cellulose and its nanocomposites for biomedical applications. In Oksman K, Sain M (eds) Cellulose nanocomposites. Processing, characterization, and properties. American Chemical Society, Washington DC Wan YZ, Luo H, He F, Liang H, Huang Y, Li XL (2009) Mechanical, moisture absorption, and biodegradation behaviors of bacterial cellulose fiber-reinforced starch biocomposites. Compos Sci Technol 69 1212-1217... 

The viscosity range of CN products can be adjusted in advance by choosing the starting cellulose with an appropriate degree of polymerization (DP). A study of the different celluloses examined the impact of various cellulose properties, such as morphological factors (percent crystallinity, fiber length, and distribution), chemical composition (DP, ash content), and hemiceUulose and lignin content, on the nitration behaviors of cellulose (55). 

Flame-retardant textiles are textiles or textile-based materials that inhibit or resist the spread of fire. Factors affecting flammability and thermal behavior of textile include fiber type, fabric construction, thermal behavior of textile polymer and its composition as well as the presence or absence of flame additives. On the other hand, flame-retardant additives can be classified by their chemical composition or by mode of action, i.e., gas phase action or by the formation of protective barrier [49, 50]. Moreover, flame-retardant functional finishes of cellulose-based textiles can be accomplished by [i] using inorganic phosphates, (ii) with organophosphorous compounds, [iii) with sulfur-derivatives or (iv) by grafting flame retardants monomers [49,50]. 

By analyzing the fractions collected after hydrolysis, one may obtain the total amount of cellulose, hemicellulose and lignin present in the fiber. Thus, the chemical composition (by weight) for coconut fiber was 28.0% cellulose, 19.8% hemicellulose and 41.1% Hgnin. According to Luz et al. [21], the cellulose, hemicellulose and the hgnin components are responsible for the thermal and mechanical behavior of the material. Thus, it is extremely important to determine the quantity of each of these components in the fiber. 

For short-term studies of behavior, an ideal test substrate would be a neutral, nonliving substrate with no nutrient value to which test chemicals can be added. Filter paper has been used in the past (e.g., Dethier 1941), but cellulose acetate filters (Bristow et al. 1979 Navon et al. 1993) and disks made from thin glass fibers (StMler Hanson 1976 Adams Bemays 1978) also have been used for their ease of chewing compared to filter paper, in addition to their chemical purity, absorbency, and uniformity. 

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