Thermoanalytical Study of Durable Press Reactant Levels on Cotton Fabrics

Abstract

A current goal of our research is to identify unknown durable press (DP) finishes on cotton fabrics using only thermal analytical techniques. In pursuit of this goal, we have treated 100% cotton printcloth with five low- and nonformaldehyde finishes at four to six treatment levels. Two polycarboxylic acids—citric and butanetetracarbox ylic—were used with sodium hypophosphite catalyst to produce nonformaldehyde fabric finishes. Three formaldehyde-based finishes were produced with 1,3-dimethylol- 4,5-dihydroxyethyleneurea. Results of differential scanning calorimetric and ther mogravimetric analyses were compared with those of untreated and catalyst-treated controls. The thermal parameters tested to recognize reactants included amount of residue, maximum rates of weight loss, peak temperatures, and peak areas, along with various parameter ratios. There were progressive changes in all fabric thermograms as agent/catalyst levels increased. Even at the 2% agent level, we could detect that fabric had been treated. It was also not difficult to distinguish between the low- and nonformaldehyde DP finishes. Thermal profiles of catalyst controls indicated that the catalyst was a substantial contributor to thermal parameters. This study has brought fabric finish identification using thermal analyses much closer to reality.