Changes in dyeability and morphology of cotton fiber subjected to cellulase treatment

Abstract

Unprocessed and mercerized cotton fibers were treated with commercial crude cellulase. The changes in the dyeability and structural features of the fiber due to cellulase treatment were studied. The dyeability was examined in terms of uptake of three reactive dyes and the apparent affinity of Congo Red to cotton fiber. The dyeability of the unprocessed fiber was assumed to be influenced by some impurities present in it. This fiber probably resembled polynosic fiber in molecular aggregate at a certain stage of hydrolysis. Mercerized cotton showed a similar pattern in dyeability as weight loss increased, regardless of dye species. Enzyme more easily penetrated the mercerized fiber than the unprocessed fiber. Cellulase treatment influenced the X-ray crystalline reflection pattern for the mercerized fiber but nominally influenced that for unprocessed fiber. Scanning electron micrographs revealed that cellulase treatment caused swelling of the fibrils. They also revealed that the disordered regions between the fibrils in the secondary walls were removed at low weight loss for the unprocessed fiber. The mercerized fiber at high weight loss had large cracks oblique to the fiber axis and showed no individual fibrils in the secondary wall. The primary wall was removed in the initial stage of hydrolysis for both the unprocessed and mercerized fibers.

Bending and Shear Properties of Cotton Fabrics Subjected to Cellulase Treatment

“…This means that a reduction in the fin ness of the cotton fibers takes place due to enzymat hydrolysis. Our work also suggested that enzymat hydrolysis occurs in the secondary wall of the cottf fibers, even during the initial step of hydrolysis, due ie coexistence of molecular disaggregating enzymes i the cellulase [4]. ' Polyester fabrics treated with an aqueous sodium hyroxide solution, also associated with a reduction in ibric weight, have a silky handle.…”

“…We ave selected KES to measure the bending and shear roperties of cotton fabrics after the same cellulase treatient we reported on previously [4].…”

Mechanical Properties and Fabric Hand of Cotton Fabrics Subjected to Cellulase Treatment.

“…It was noted that the parameters of bending and shear properties decreased for all cotton fabrics tested. The reduction [2] in fiber fineness induced by cellulase treatment decreased the friction force between fibers, and improved the recovery from bending and shear deformations. The reduction of fiber fineness reasonably decreased not only the elastic parameters of B and G, but also the inelastic parameters of 2HB, 2HG and 2HG5.…”

“…Previously, we reported that the dyeability [1,2] and crystallinity [2] of cotton fibers changed even in the first step of cellulase treatment. Observation using a scanning electron microscope [2] revealed that the cellulase treatment decreased fiber fineness by eliminating the primary layer, resulting in a material weight loss of approximately 5% [2].…”

“…Observation using a scanning electron microscope [2] revealed that the cellulase treatment decreased fiber fineness by eliminating the primary layer, resulting in a material weight loss of approximately 5% [2]. It is believed that the degradation inside cotton fiber, in addition to the reduction in fiber fineness, has a significant effect on fabric properties, as does fabric construction.…”