Mechanical Properties of Cotton Yarns Mercerized in Liquid Ammonia and Sodium Hydroxide

Abstract

Yarns spun from high- and low-maturity cottons were mercerized in liquid ammonia in a continuous process, and in liquid ammonia and sodium hydroxide in skein form under various tensions. Both swelling agents produced similar changes in mechanical properties (breaking strength, tenacity, elongation-at-break, and initial modulus) under comparable conditions. Mercerization under high tension increased breaking strength and tenacity and decreased elongation-at-break. Slack mercerization in caustic resulted in elongations-at-break substantially higher than did ammonia treatment. A major difference between reagents was noted during treatment. When skeins were swollen slack and then restretched, much greater force was required to restretch ammonia-swollen skeins, and they could not be stretched as much as those that were caustic-swollen. Measurements of length changes in yarns during swelling, tensioning, and deswelling gave quantitative data to substantiate this observation. Differences in mechanism of swelling are discussed in relation to these findings.

Tensile, physical, and microstructure properties of glycine treated cotton fibers

“…Treatments involving swelling are better in this respect, generally improving fiber, yarn, and fabric strength and dyeing ability. 17–19 A number of workers have reported beneficial changes to cotton fiber after treatment with both liquid ammonia and caustic mercerization. 12,14,15 Rouselle et al .…”

“…Treatments involving swelling are better in this respect, generally improving fiber, yarn, and fabric strength and dyeing ability. [17][18][19] A number of workers have reported beneficial changes to cotton fiber after treatment with both liquid ammonia and caustic mercerization. 12,14,15 Rouselle et al 14,15 found the slack treatment of fibers in a caustic mercerization increased both tenacity and elongation, but slack treatment in ammonia resulted in no change to the tenacity and a moderate increase in elongation.…”

Established an eco-friendly cotton fabric treating process with enhancing anti-wrinkle performance

“…N bonds to form a swelling complex, which is easily decomposed when the ammonia is removed. 28,29 Deeply mechanism was proposed recently elsewhere using modern neutron crystallography combined with molecular dynamics simulations technologies. 31 The final cellulose polymorph after the liquid ammonia treatment depends on the way of ammonia removal.…”

“…It then goes into the crystalline areas, accompanied by swelling and forming soda-cellulose complex by replacing the ionizable hydrogens in the OH groups with sodium ions. 28,29 After removing NaOH, the polymorph of cotton fabrics transferred from its native cellulose I β to cellulose II. Accordingly, the initial cotton fabric has improved luster, smoothness or handle, dye uptake, mechanical properties, and dimension stability.…”

Liquid Ammonia Mercerization of Jute

“…Interest in liquid ammonia as a swelling agent for mercerization of cotton yarns and fabrics [1,[3][4][5]8] has increased recently because of its inherent advantages over caustic soda, such as ease and rapidity of wetting, ease of removal of the reagent, reduced stream pollution, and lower cost due to recovery of the reagent. A few patents have made the method commercially viable [2, 9J.…”