Presensitization of Cotton by the Deposition of Polymers of N-Methylol Compounds

Abstract

A study was made of the presensitization of cotton by deposition of N-methylol poly mers and catalyst in the fabric, to permit subsequent curing of the fabric in garment form. The following N-methylol compounds were studied: triazone-formaldehyde, triazine-formaldehyde, dimethylolethyleneurea, melamme-formaldehyde, modified mela mine-formaldehyde, and dimethylolurea. The method of deposition involved impregna tion of the cotton fabric with an aqueous solution of the N-methylol compound and an acid catalyst. After impregnation, the damp fabric was permitted to remam at room temperature or a slightly higher temperature for 24 hr to promote polymerization of the reagent within the fiber. It was found that for all the N-methylol compounds exammed, significant amounts of polymer could be deposited within the cotton with substantially no loss in fabric strength and no impartation of crease recoveru or wash-and-wear properties. The treated fabrics could be subsequently cured by heating at an elevated temperature to develop these properties, as well as to impart sharp creases. Thus, the polymer deposition method was found to produce presensitized cotton fabrics. The attainment of sharp durable creases was easier, however, than the development of a high level of wash-and-wear properties. The stability to storage of the polymer-presensitized fabrics was examined under several conditions and compared with that of cotton presensitized by the same monomers. The stability to storage of the polymer-presensitized fabrics was superior to that of the monomer-presensitized materials in several cases. However, the levels of wash-wear properties attained to date with the polymer treatments were not as high as those required by current commercial usage, and an extra step is required by the process. With one of the compounds examined, a melamine-formaldehyde, a cured fabric which had a balance between strength retention and wash-wear properties superior to that normally obtained with resin-treated fabrics was obtained. However, under these experimental conditions a high level of crease recovery and wash-wear properties was not obtained. While no commercially justifiable treatment has so far emerged from these results, the data are of theoretical interest, particularly since they suggest that polymer deposition within the cotton fiber may mitigate the strength losses produced in wash-wear treat ments. The data also confirm the already prevalent concept that polymer deposition alone within the cotton fiber does not significantly contribute to wash-wear properties.