Xylan biodegradation

Thermoplastic xylan derivatives have been prepared by in-hne modification with propylene oxide of the xylan present in the alkaline extract of barley husks [424,425]. Following peracetylation of the hydroxypropylated xylan in formamide solution yielded the water-insoluble acetoxypropyl xylan. The thermal properties of the derivative quahfy this material as a potential biodegradable and thermoplastic additive to melt-processed plastics. Xylan from oat spelts was oxidized to 2,3-dicarboxyhc derivatives in a two-step procedure using HI04/NaC102 as oxidants [426]. 

Large amounts of agricultural waste products, such as corn cobs, are continuously provided in several developing countries. Xylan is considered to be a green polymer that may play an essential role in the renewability of waste products due to its biodegradable and biocompatible nature. Furthermore, as shown in this chapter, xylan presents particular properties that allow a wide range of applications. 

Kayserilioglu, B. S., Bakir, U., Yilmaz, L. Akkas, N. (2003). Use of xylan, an agricultural by-product, in wheat gluten based biodegradable films mechanical, solubility and water vapor transfer rate properties. Bioresource Technology, Vol. 87, 3, (May 2003), pp. (239-246), ISSN 0960-8524... 

FIGURE 28.5 The chemical structure of a typical xylan. (From Builders, P.F. and Attama, A.A., Functional properties of biopolymers for drug delivery applications, in Biodegradable Materials, Johnson, B.M. and Berkel, Z.E., Eds., Nova Science Publishers Inc., New York. Copyright 2011, with permission from Nova Science Publishers, Inc.)... 

Lignin B is an antibacterial, namral, renewable and non-toxic product, and for this reason it was integrated into xylan-based biodegradable films obtaining strong antibacterial effect towards tested microorganisms [144] (Table 8.11). 

In recent ten years, xylans and mannans have been studied as potential raw materials for biodegradable films. Sometimes they are blended with other polymers or mixed with nanoparticles to achieve enhanced properties. This chapter covers the occurrence, structure and properties of xylans and mannans as well as recent smdies on xylan- and mannan-based blends, composites, and nanocomposites. 

Xylan accounts for roughly one-third of renewable biomass available on earth but does not have enough applications in the industry. Xylan has been found to form films, and to improve the film formation and properties, xylan has been blended with other natural polymers (Table 9.2). The aim has been to create biodegradable materials with strong interactions, enhanced mechanical performance, and decreased water vapour permeability. 

Saxena, A., Ragauskas, A.J. Water transmission barrier properties of biodegradable films based on cellulosic whiskers and xylan. Carbohydr. Polym. 78, 357-360 (2009)... 

Hemicelluloses, Polysaccharides, Xylan, Glucuronoxylan, Arabinoxylan, Mannan, Glucomannan and galactoglucomannan. Polymer, Bios3uithesis, Biodegradation, Properties, Applications... 

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