Cotton textiles application areas

The split into the various textile dyestuff application areas has, over recent years, seen a shift towards the two main outlets of disperse dyes for polyester and reactive dyes for cellulosics (mainly cotton), at the expense of directs and vat dyes for cotton, cationic dyes for acrylics and acid dyes for polyamide. The latter fibre has shown a comeback in recent years with the popularity of microfibres in sports and leisure wear. The position in 1998, with disperse dyes dominating in value terms, was as shown in Table 2.6. 

The potential industrial interest for poly(2-pyrrolidone) (PA4) in relevant fields of application (namely, textiles) arises from its excellent mechanical properties comhmed with a hydrophilic behavior similar to that of cotton. Other areas of applied interest may be those of membranes and biomedical devices. However, its industrial production bas not yet been developed to any appreciable extent because of the many drawbacks existing in both its synthesis and its processing. 

The applications of chitosan for improving dyeability of cotton fabric has been widely studied [73, 177, 48], In the textile area, the higher the active site of chitosan favors the higher the dye adsorption (including natural dye) as well as film formation on fiber surface [92]. Chitosan can easily adsorb anionic dyes, such as direct, acid and reactive dyes, by electrostatic attraction due to its cationic nature in an acidic condition. It is postulated that the affinity of chitosan to cotton would be by Van der Waals forces between them because of the similar structures of chitosan and cotton. 

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