Abstract
Dimethylol ethylene urea or methylated methylol melamine was used to prepare “wash and wear” cotton fabrics.
The cotton fabrics finished with dimethylol ethylene urea by using pad-cure process have higher wet crease recovery and lower dry crease recovery than those by pad-dry-cure process. This tendency was enhanced by pre-swelling of the sample fabrics with alkali solution as reported by Steele.
When a drying process was added before the curing process, the wet crease recovery decreased remarkably and the dry crease recovery increased.
The rate of condensation reaction and the reactivity of the finishing agents with cellulose, were studied to explain these results. It was confirmed by the electron microscopic observation that the monomer impregnated into lamella migrated into inter-lamellar spaces during the drying process when dimethylol ethylene urea was used.
This interpretation is supported by the fact that when the organic solvent of high boiling point was used as the solvent of finishing agents, high wet crease recovery was maintained even if the drying process was inserted.
When the methylated methylol melamine was used, the wet crease recovery did not increase by pad-cure and the effect of inserting of a drying process upon the dry and wet crease recoveries was not so large.
It was concluded from these results that methylol melamine condensed rapidly in the amorphous region in lamella without forming covalent cross links in the water sensitive region, and expanded this region with the progress of the reaction.
