COLOUR MODIFICATION IN COTTON FIBERS WHEN TREATED WITH POLICARBOXILIC ACIDS

Abstract

ABSTRACT: Cellulosic fibres are well known because of their properties. However, some disadvanteges can be observed such as lack of dimensional stability and crease resistance. In order to minimise those properties some finishing treatments where crosslinking agents are added can be performed. Dimetildihydroxiethylenurea is widely know for that kind of treatments but it produces formaldehide what is considered as a cancerigen agent. Polycarboxilic acids ara considered as the ones that can replace DMDHEU. The use of those acids involve treatments at high temperatura (170-200º C) what can imply a change in color of the treated fabrics. Recent studies show that apart from crosslinking agentes they can be used as finishing resins to add some substancies to textiles in order to obtain an Smart textil. An example can be the use of those acids to link microcapsules to fabrics avoiding them to drop off from the fabric because of gravity. In this study we have evaluated different acids knowing whih ones reduces the yellowing effect. Moreover we could determine which ones were the conditions to minimise yellowing or reducing it. It could be observed that catalyser presence increases the crosslinking effect and reduces the change in color and concluded that temperaturas higher than 180º C are worthless as they do not allow to increase the number of carboxy groups.