It is known that bleaching treatment primarily brings about the
oxidation of the sulfur-containing amino acids by way of disulfide
bond fission, probably by the S–S fission route [4]. This makes the
fiber hydrophilic and porous, which aid swelling. Extensive bleaching,
however, decreases s3 and increases I3, which is indicative of
some sort of electrostatic interactions being established between
the hydrophilic ends of the polymer chain segments.