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

Abstract

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.

Study on Charge Distribution of Carboxymethylated Cotton Fabric by Streaming Potential/Current Measurements

“…The method was adopted from previous work. 10 Small pieces (2.5 × 2.5 cm) were cut from different parts of the treated sample. These pieces were further cut into smaller pieces (3 × 3 mm).…”

“…[6][7][8][9] In prior work, cotton fabric made anionic via carboxymethylation with monochloroacetic acid can be crosslinked in a second step by application of agents with the opposite ionic charges. 10 Hashem et al reported enhancing wrinkle free properties of carboxymethylated cotton fabric via ionic crosslinking with poly(vinylpyrrolidone). 11 In addition, layer-by-layer self-assembly deposition of polyelectrolytes on ionic cotton have been studied in recent reports.…”

Wrinkle-resistant finishing with dimethyloldihydroxyethyleneurea (DMDHEU) — the effect of co-catalyst

“…DMDHEU is widely used to impart easycare and durable press properties to cotton apparel because it is cost effective and efficient. 17 However, DMDHEU produces free formaldehyde during application, which is considered probably to be carcinogenic, based on studies on animals which have revealed neoplastic lesions at the point of contact in the respiratory tract, although there is limited evidence of its carcinogenic effect on the human respiratory tract. 17,18 The results show that DMDHEU-treated cotton specimens contain small quantities (58 ppm) of free formaldehyde which can be toxic, allergenic and carcinogenic.…”

“…17 However, DMDHEU produces free formaldehyde during application, which is considered probably to be carcinogenic, based on studies on animals which have revealed neoplastic lesions at the point of contact in the respiratory tract, although there is limited evidence of its carcinogenic effect on the human respiratory tract. 17,18 The results show that DMDHEU-treated cotton specimens contain small quantities (58 ppm) of free formaldehyde which can be toxic, allergenic and carcinogenic. Extensive efforts have been made to find formaldehyde-free crosslinking agents to process cotton fabrics but numerous disadvantages such as high cost, inadequate reactivity, fabric yellowing, excessive fabric tendering, and toxicity were observed in all alternative agents.…”

“…Extensive efforts have been made to find formaldehyde-free crosslinking agents to process cotton fabrics but numerous disadvantages such as high cost, inadequate reactivity, fabric yellowing, excessive fabric tendering, and toxicity were observed in all alternative agents. 2,17 Compared with other chemical agents that can be used for wrinkle-resistant treatment, DMDHEU is a low cost chemical with superior results. As shown in Table 2, the free formaldehyde content drops to a 'not detectable' level when TiO 2 /nano-TiO 2 is added in the treatment.…”