Monday, February 23, 2009

Chitosan

Textile industry is an omnipresent industry. It has found applications over such wide range, which perhaps no other industry, except Information technology and Computers, could found. This is the reason various branches of Science and technology have been collaborated with this industry. This collaboration makes the application of various fundamentals and materials possible in textile industry. The field of Biomaterials is one such field, which provides various new materials to textile industry for obtaining better results in most ecofriendly and economical ways. Successful application of enzymes on shop floor in textile wet processing is a very good example. Now another biomaterial is about to enter in the textile industry, this material called, as “Chitosan” is not a new biomaterial; however, some lateral thinking of research workers has found some novel application of this biomaterial.

A glance at Chitosan:

Chitin is one of the most abundant polysaccharides found in nature. It is a white flaky material, found in the exoskeletons of arthropods such as insect spiders, some fungi, crabs, and shrimp. Chitosan is a derivative of Chitin produced by N-acetylation of the chitin molecule. It is often considered a cellulose derivative, although it does not occur in organisms producing cellulose. The difference between cellulose and Chitosan is that the 2-hydroxy group of the cellulose has been replaced with an acetamide group. This results in several Beta-(1 -> 4)-2-acetamido-2-deoxy-D- glucopyrnaose structural units (GlcNAc).Chitin and Chitosan have the potential to reduce and to solve some problems for creating "Greener" environment.

The chemical structure of Chitin and Chitosan are shown in Fig.

Chitosan in Wool Processing:

Additives and additional processes for bet

ter wool processing are being researched extensively for better dyeing, anti-felting, and anti-shrinking properties. Chitosan and Chitin have also enticed the attention of the research workers for their application in this area. In protonated form, Chitosan behaves like a polyelectrolyte, forming a viscous solution and interacting with oppositely charged molecules. However, it has weak binding properties for the fibre, in addition the even distribution on the fibre is very difficult obtain.

The binding properties of Chitosan on wool using a solution containing a non-ionic surfactant have been studied and it has also been shown that the oxidative treatment with the help of hydrogen peroxide and enzymes before the application of Chitosan, gives better binding properties uniform distribution.

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