Synthesis of amine-functionalized methacrylic acid-g-poly(ethylene terephthalate) fiber and its Congo red removal ability

The two kinds of amine-type adsorbents were synthesized by reacting hexamethylenediamine (HMDA) and tetraethylenepentamine (TEPA) with methacrylic acid-g-poly(ethylene terephthalate) (MAA-g-PET) fiber for the removal of Congo red (CR) dye from an aqueous solution. The effect of solvents (toluene, ethanol, 2-propanol, and water) on modification of carboxylic acid group of MAA-g-PET fiber to amine groups (HMDA and TEPA) was investigated. Ethanol and 2-propanol provided a higher amination amount of PET fibers for HMDA and TEPA, respectively. The amination amount of PET fibers increased with increasing concentration of amine (vol%) and graft yield. Effect of various parameters such as pH, graft yield, treatment time, and initial dye concentration on the removal amount of CR on chelating fiber was studied. The removal of CR was higher on the TEPA–MAA-g-PET fiber than on HMDA–MAA-g-PET fiber. The effective pH was 3 for adsorption on HMDA–MAA-g-PET fiber and 6 for adsorption on TEPA–MAA-g-PET fiber. The maximum removal capacities of HMDA–MAA-g-PET fiber and TEPA–MAA-g-PET fiber were 11 and 21 mg/g fiber adsorbent for CR. Consequently, the amine-functionalized MAA-g-PET fiber has demonstrated potential as an effective adsorbent for the removal of acidic dyes from aqueous media.