Microscopical Comparisons of Some Reactions of Cotton Cellulose with Ethyleneurea Derivatives

Abstract

Reactions of cotton cellulose with dihydroxyethyleneurea (DHEU) and with dimethyloldihydroxyethyleneurea (DMDHEU) in the presence of Zn(NO₃)₂, ZnCl₂, Mg(NO₃)₂, and MgCl₂ as catalysts have been compared at various temperatures and times. Temperatures and times selected covered the range of conditions pertinent to the "delayed cure" process for making permanently pressed garments and, therefore, included slow rates of reaction from room temperature up to 65° C followed by high temperature cures at 160° and 180°C. Changes in fiber morphology which accompany changes in physical properties have been illustrated with electron micrographs of fiber sections. Correlations of these microscopical observations with those previously made on reactions between cellulose and dimethylolethyleneurea (DMEU), and with reaction rates and changes in physical properties are made. At no temperature of curing and with none of the catalysts used were reaction products of DHEU resistant in ultrathin section to solution in cuene; DMDHEU reaction products when catalyzed with zinc nitrate were resistant when reacted at temperatures as low as 65° for prolonged curing times.