Degrading wool

Biological Degradation. Wool may be targeted by a variety of keratinophilic bacteria and fungi, which break down the component proteins via enzymatic oxidation, reduction or hydrolysis this type of attack predominantly tends to occur in the amorphous regions, particularly in the cuticle. Wool fibres are also susceptible to attack by several species of moths and beetles. 

Pure cultures are obtained from a commercial or private culture collection for these studies. Shrivastava eta/. [23] surveyed 10 fungal isolates to see which would degrade wool. Pranamuda and Tokiwa [50] obtained 25 strains of Amycolatopsis and tested their abilities to degrade poly(L-lactide). Ohkawa et al. [22] used seven fungal species to study the biodegradation of chitosan-gellan and poly(L-lysine)-gellan. 

An early conservation use of pine resin was as a hot-melt coating applied to degraded wool in the eleventh century (Cronyn and Horie, 1985). The oleoresin and the rosin derived from it have been included in recipes for artistic materials... 

The principal oxidi2ing agent used in degradative shrink-resist treatments is chlorine. Free chlorine reacts very rapidly with wool hence it is difficult... 

Jones, RW. and Westmoreland, D.J. (1998). Degradation of nonylphenol ethoxylates during the composting of sludges from wool scour effluents. Environmental Science and Technology 32, 2623-2627. 

Complete removal of degraded or damaged portions of the wool (not merely the cuticle) using (i) protease treatment (ii) formic acid rinse and application of a softener. 

Since wool is attacked most rapidly by sulphuric acid of intermediate concentration, it is important that drying is carried out either at a relatively low temperature so that reaction of the acid with wool is slow, or very quickly so that the time of exposure of the wool to the critical acid concentrations is brief [146]. Ideally, all the sulphuric acid in the wool is absorbed chemically as bound acid that causes little hydrolytic damage. It is the free acid that can concentrate locally and cause serious degradation. The acid picked up by the vegetable impurities, on the other hand, is free acid that has the desirable effect of beginning the process of attacking the cellulose [286]. 

Liposomes (section 10.3.4) have been suggested as auxiliary agents in wool chlorination since they give improvements in the consistency and homogeneity of the oxidative treatment, minimising degradation of the wool and facilitating subsequent treatments [61,62]. 

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