Studies on disulfide‐crosslinked nylon. I. Elastic disulfide‐crosslinked polycaprolactam fiber

摘要

AbstractElastic disulfide‐crosslinked polycaprolactams of different sulfur contents (0.4‐3.3) were prepared by the reaction ofN‐methoxymethyl polycaprolactam (D.S., 0.30) with different amounts of thiourea, the hydrolysis with excess potassium hydroxide, and the spinning into aqueous hydrogen peroxide.The fibers obtained exhibited high elongation at break (500‐300), low initial modulus (13‐1 kg/mm2), and high elastic recovery. The initial modulus decreased with increased crosslinking. Heat‐treatment of the fibers at 140°C lowered the initial modulus remarkably. The effect of the crosslinking and the residual methoxymethyl substitution on the structure and the physical properties of the untreated and heat‐treated fibers is discussed.The residual methoxymethyl groups were removed completely from the fibers by hydrolysis with formic acid. The removal led to marked reduction in the elongation and much increase in the i