Preparation of a thermosensitive fiber and its carbon dioxide adsorption/desorption properties

A thermosensitive fiber (VF-NIPAAM-co-AM) was developed by grafting N-isopropylacrylamide (NIPAAM) and acrylamide (AM) onto the surface of viscose fiber (VF) through the simultaneous grafting copolymerization approach. The grafted fiber was subsequently aminated with triethylenetetramine (TETA) to prepare a solid amine adsorbent for CO2 capture. The effect of NIPAAM/AM molar ratio on the thermosensitive properties of the grafted fiber was investigated. It was found that the contact angle of VF-NIPAAM-co-AM increased with the increasing of NIPAAM/AM molar ratio. For all the prepared fibers, the contact angle of VF-NIPAAM-co-AM at 343 K was higher than that at 293 K, indicating the thermosensitive property of the grafted copolymer fibers. After amination, the contact angle of VF-NIPAAM-co-AM-TETA at 293 K and 343 K were 79.86°and 84.14°, respectively. Even though the contact angles of aminated fibers decreased, the fiber still retained a certain thermosensitive property. Studies on the adsorption and desorption behaviors of VF-NIPAAM-co-AM-TETA and VF-AM-TETA indicated that CO2 could be more efficiently and completely desorbed from VF-NIPAAM-co-AM-TETA at 80 °C than from VF-AM-TETA, a structurally similar fiber but without NIPAAM.