Eco‐friendly durable press finishing of cellulose‐containing fabrics

Abstract

To impart easy-care properties to cellulose-containing fabrics along with avoiding any harmful effects of formaldehyde on both the health and the environment, attempts have been made to use citric acid (CA) as an ester crosslinking agent along with different catalytic systems in the absence and presence of certain additives. Further, fixation conditions, type of crosslinking agent, as well as type of substrate have been studied. Results revealed that the enhancement in carboxyl content, performance properties, and the decrease in tear strength (TS) as well as in whiteness indices (WI) of the finished fabric samples were increased by increasing CA concentration up to 80 g/L and by raising thermofixation temperature from 140 up to 180°C for 90 s. Inclusion of triethanolamine hydrochloride (TEA. HCl), decreased the carboxyl content, TS, color strength K/S, as well as oily stain release rating (SRR) of the finished fabric samples along with an increase in bound nitrogen (%N), wrinkle recovery angle WRA, and an improvement in WI without affecting the durable press rating (DP). Within the range examined (0-30 g/L), increasing PEG-600 concentration improved the wet resiliency, TS, as well as WI properties of the finished samples. Increasing DMDHEU ratio in the CA/DMDHEU crosslinking system gave rise to an increase in %N, WRA (dry and wet), DP, as well as in free CH 2 O of finished fabrics, along with a slight improvement in WI values. On the other hand, the TS, carboxyl content, K/S, SRR values of the finished fabric samples were lower at a higher DMDHEU ratio. Increase in carboxyl content, %N, WRA (dry and wet), DP and SRR, as well as extent of post dyeing (K/S) of the treated fabric samples upon using different ester crosslinking agents followed the descending order: citric acid Ͼ pyromellitic dianhydride. The opposite holds true for the TS, and WI values. Among the esterifying catalysts used, and for a given set of finishing conditions, NaH 2 PO 2 ⅐ H 2 O proved to be the most effective one, and the following order of effectiveness may be drawn: NaH 2 PO 2 ⅐ H 2 O Ͼ K 2 HPO 4 Ͼ Na 3 -citrate Ͼ Na 2 -tartrate. Inclusion of silicone softener in the finishing formulation brought about an improvement in softeness degree, WRA, %N, DP, TS as well as K/S values along with a decrease in carboxyl content, SRR, and WI values of the treated fabric samples, regardless of the used silicone softener.The performance properties of the finished fabric samples were determined by the type and nature of the substrate.

Antimicrobial activity of cotton fabrics containing immobilized enzymes

“…Crosslinking cotton fabric containing carboxyl groups 12,13 Cotton fabric samples were padded twice through a finishing bath containing certain amounts (50, 100, 150, and 200 g/L) of BTCA, respectively, as a reactive crosslinking agent, Na-hypophosphite (80% owBTCA) along with a nonionic wetting agent to a wet pick up of 100%, followed by drying at 858C for 10 min, and curing at 1808C for 2 min. The crosslinked cotton fabric samples were washed at 508C for 30 min, thoroughly rinsed with distilled water to remove excess and unfixed reactants along with by products, and finally dried at 858C in a vacuum oven.…”

Simultaneous x‐linking and antimicrobial finishing of cotton fabric

“…The presence of residual aldehyde groups was known as a main cause of fabric yellowing when the fabric was treated with GA. 30 Also when CA was coapplied with antimicrobial agents, CA might release aconitic acid, which is known as a source of yellowing. 31 …”

Functionalizaton of Linen Fabric using Poly (N-vinyl-2-pyrrolidone)

“…Table 5 shows the performance properties of linen fabric crosslinked with CA or BTCA alone or in presence of PVP. Table 5 signifies that: i) estrification of linen fabrics with CA or BTCA in absence of PVP enhances the resiliency, wettability and yellowness along with a decrease in tensile strength of the treated samples, which can be attributed to esterification of the hydroxyl groups of linen cellulose with the carboxyl groups of the CA or BTCA via an anhydride intermediate mechanism as well as the formation of unsaturated acids bound to the surface of the finished fabrics (13,16,17) and ii) estrification of linen fabric with CA or BTCA in presence of PVP is accompanied with an enhancement in the nitrogen content as well as tensile strength along with a decrease in the resiliency, wettability and yellowness of the treated fabrics. This could be related to the decrease in the extent of ester crosslinking of the cellulosic hydroxyl groups via increasing the viscosity of the finishing bath thereby hindering the diffusion and penetration of CA or BTCA within the fabric structure and hence the altering in the values of the aforementioned properties (16) and iii) in absence or presence of PVP, BTCA improves the nitrogen content (only in presence of PVP), resiliency, wettability and yellowness of the treated fabrics compared with the fabrics treated with CA.…”