DEGRADATIVE WOOL SHRINKPROOFING PROCESSES .2. LIPID MODIFICATION

We have investigated lipid modifications produced by some degradative shrink-proofing processes. Using thin-layer chromatography with flame ionization detection, we have determined the composition of the lipids extracted from untreated and treated wools with chloroform/methanol azeotrope. The treatment medium modifies the CMC, facilitating penetration of the reactive agents. In the case of formic acid, the swelling of the fibers and modification of the intercellular cement are reflected in a higher subsequent lipid extraction, mainly sterols and polar lipids. In the case of isopropanol/water, dissolution of a large amount of the lipids during the treatment is reflected in the smaller amount of lipids extracted from these treated fibers, the amounts of free fatty acids, sterols, and polar lipids being markedly reduced.