Applying a bisulfite adduct of polyisocyanate to cotton fabrics as a durable press finishing agent

The bisulfite adduct of polyisocyanate (BAP), designed and synthesized in our laboratory, is applied to cotton fabrics as a durable press finishing agent. The dry wrinkle recovery angles of the fabrics are increased by treatment with BAP alone, but the maximum attainable value can only reach the range of 180°-190°, which is less efficient than with modified dimethyloldihydroxyethyleneurea (266°) and citric acid (231°). In order to obtain high performance fabrics, we attempt to combine BAP with modified dimethyloldihydroxyethyleneurea or CA for cotton fabrics as durable press finishing agents. The fabrics treated with 4.0% BAP and 4.5% modified dimethyloldihydroxyethyleneurea in a single bath give satisfactory durable press performance with improved tensile and tear strength and a little-changed whiteness index. Nonformaldehyde fabrics with good durable press performance are produced by treatment with 4.0% BAP in combination with 7% citric acid (CA) under conditions of drying 3 minutes at 80°C and curing 2 minutes at 170°C with sodium hypophosphite as a curing catalyst.