Synthesis and application of new temperature-responsive hydrogels based on carboxymethyl and hydroxyethyl cellulose derivatives for the functional finishing of cotton knitwear

A unique cellulose polymer-based hydrogel with specific dual-responsive absorption properties was prepared from carboxymethyl (CMC) and hydroxyethyl (HEC) cellulose in an aqueous solution employing citric acid (CA) as a crosslinking agent. The effect of preparation conditions, such as the polymer content and the CA amount, on the crosslinking process was investigated by estimating the formation of ester bonds (FTIR), as well as the hydrogel temperature-transition (DSC and optical transparency), weight-swelling ration measurements and morphology (SEM) as a function of time, temperature, and pH medium. The results show that the increment of the HEC content in the polymer solution diminishes the crosslinking degree and, consequently, reduces the pH dependency of the hydrogel. The results also show that the temperature-responsive swelling ability of hydrogel can be formulated based on the hydrogel's composition, and the degree of crosslinking. The swelling profile of knitted cotton fabric treated with a thin surface layer of modifying hydrogels was studied as a function of its fabrication and the conditions of its incubation, showing an opposite effect.