Recovery and Strength of Chemically Modified Single Cotton Fibers

Abstract

Low-twist yarns made from Deltapine cotton were ethanol-extracted and chemically treated while slack. Fibers were taken from yarns treated with formaldehyde, by various procedures producing differences in swelling of the fiber structure when cross-linked; dimethylol ethyleneurea; N-methylol-N'-methylethyleneurea; and oleoyl chloride. Single fibers progressively lose strength and elongation with increasing cross links when tested at 70°F, 65% RH and when wet. Cross links introduced in the swollen fiber structure usually cause less strength loss than those introduced in the nonswollen structure. Tensile strain recovery for single fibers increases with increasing cross links. The initial are more effective than the subsequent cross links. Increased energy recovery is related to increased strain recovery. Single fibers cross-linked in slack yarns show increases in recovery with decreases in stiffness. The retention of strength and the improved ability to recover are limited to some modifications, especially under the wet conditions. Changes in mechanical properties of cottons by smooth-drying treatments are due, in part, to changes in mechanical properties of the individual fibers.