Polymerization and Condensation Reaction of N-Methylol Acrylamide within Cotton Fabric

Abstract

Problems on the polymerization and condensation reaction of N-methylolacrylamide within cotton fabrics in which K₂S₂O₈, (NH₄) ₂S ₂O₈, or H₂O₂ was used as initiator and NH₄ Cl or (NH₄ )₂HPO₄ used as the acid condensation catalyst were investigated primarily from the standpoint of the crease resistance of the treated fahric. The results obtained are as follows. The pre-drying process can be neglected, as almost the same result could be obtained even in the case of direct curing procedure, in which care should be taken not to over- cure. Crease recovery and abrasion resistance (flat) of the treated fabric increased with higher value of resin content ; tear strength, on the contrary, decreased presumably with some intrinsic cause. The effect of the addition of acid catalysts such as NH₄Cl on the extent of the crease resistance was considerable, although some marked improvement was obtained in neutral catalysts such as K₂S₂O₈ alone. The addition of comonomers such as acrylamide and hexamethylene diamine HCl-salt as well as softeners to the treating bath was effective in improving the strength losses induced by this treatment. Aftertreatment of the N-methylolacrylamide-treated fabric with hexamethylenediamine or thereafter with formalin was also effective, since some what continuous distribution of the different kinds of network-structures within the fiber could be obtained by this procedure. Durability of the treated fabric for boiling-alkali launderings was excellent.