Enhancement of Wrinkle Free Properties of Carboxymethylated Cotton Fabric via Ionic Crosslinking with Poly(vinylpyrrolidone)

Incorporation of poly(vinylpyrrolidone) (PVP) in the structure of cotton, carboxymethylated cotton (CMC) or ionically crosslinked cotton fabric induces besides ether crosslinking of cotton cellulose, strong columbic forces and weaker forces such as dipole—dipole, hydrogen bonds, van der Waals, or hydrophobic interactions. The ether bonds are formed in the dry state (i.e., un-swelled state), whereas, the other interactions are formed in wet state (i.e., swelled state) of cotton fabrics. Both interactions greatly enhance wet and dry wrinkle recovery angle of cotton fabric without strength loss. Fixation of PVP onto cotton or CMC fabric was achieved thermally by curing the treated fabric at 140°C for 5 minutes. Higher wet and dry wrinkle recovery angles (WRA and DRA) were obtained with lower molecular weight PVP (3000 Da) compared with higher molecular weight one (8000 Da). The results obtained also show that a balance between WRA, DRA as high as 228° and 225°, respectively, could be obtained without loss in tensile strength and elongation at break by treatment CMC fabric having carboxyl content 115 meq/100 g fabric with 4% PVP then cured at 140°C for 5 minutes. Additionally, treatment of the ionically crosslinked fabric (having 115 meq/100 g fabric carboxyl content and 0.22% nitrogen content) with 4% aqueous PVP enhances the DRA and WRA to reach a value of 289° and 286°, respectively, without any loss in the strength properties of the fabrics. These values of WRA and DRA are much higher than those obtained with cotton fabric (blank) or carboxymethylated cotton. The existence of ionic interaction and ether bonds as well as functional groups introduced into cotton fabrics were confirmed by FTIR spectroscopy.