Reactivity and Fine Structure of Cotton Mercerized in Sodium Hydroxide or Liquid Ammonia

The effect of liquid ammonia mercerization on the fine structure and reactivity of cotton sliver and yarn was compared with that of sodium hydroxide mercerization. X-ray diffractograms showed considerable decrystallization by both swelling agents, with little difference between them, and no effect of tension. The swelling produced by both reagents decreased the density of the cotton, with the percentage decrease being dependent on tension, method of removing the swelling agent, and fiber maturity, rather than on type of reagent. Accessibility to moisture, deuterium exchange, and iodine was increased by all treatments, but in general, increases with caustic soda were greater than with ammonia. Differences in enhanced reactivity towards acid hydrolysis and crosslinking with formaldehyde, attributable to mercerizing agent, were small, but in partial acetylation, greater reactivity resulted from caustic mercerization.