Urea-Phosphoric Acid Hydrolysis of Mercerized Cotton Modified with Methylated Methylolmelamine

Abstract

Mercerized cotton finished with a methylated methylolmelamine (MeMM) responded differently to hydiolysis with urea-phosphoric acid (UPac) than did similarly finished native cotton. UPac hydrolysis did not affect dry and wet wrinkle recoveries of mercerized cotton, but caused reduction in dry recovery angles of the unmodified native cotton control. Treatment with MeMM produced specimens with equally high dry and wet wrinkle-recovery angles regardless of nature of the control fabric; behavior of MeMM-treated fabrics, when subjected to UPac hydrolysis, was influenced by nature of the control fabric. With MeMM-treated mercerized fabrics, each subsequent hydrolysis removed about one-half of the bound nitrogen and virtually all formaldehyde; it destroyed dry recoveries, but had little effect upon wet wrinkle-recovery angles. Each MeMM retreatment completely restored these properties in products from mercerized cotton, but resulted in only partial restoration of recoveries in products from native cotton. X-ray diffractions after MeMM-UPac treatments of mercerized cottons indicated retention of the mixed cellulose I and II lattice of the unmodified control while products from native cotton retained the cellulose I lattice. Infrared spectra indicated that reaction, with MeMM in both cases, proceeded with loss of adsorbed water and occurred preferentially at the primary hydroxyl of cellulose. Unlike products from native cotton, modified mercerized fabrics did not show a buildup of polymer on the periphery of fiber cross sections after an increasing number of MeMM-UPac treatments. Hence, homopolymerization was not indicated in the MeMM treatment of mercerized fabrics.