Regenerated cationic dyeable polyester deriving from poly(ethylene terephthalate) waste

In this paper, sodium-5-sulfo-bis(hydroxyethyl)-isophthalate (SIPE) comonomer, which could copolymerized with bis(hydroxyethyl) terephthalate (BHET) for dyeability modification of poly(ethylene terephthalate) (PET), was prepared through transesterification reaction of sodium dimethyl 5-sulfoisophthalate (SIPM) and ethylene glycol (EG). The obtained SIPE was then polycondensation reacted with BHET which was extracted from waste PET fiber depolymerization under nitrogen atmosphere with excess EG as glycolysis agent and zinc acetate (Zn(Ac)2) as catalyst, to achieve regenerated cationic dyeable polyester (rCDP). Chemical structure, thermal properties, intrinsic viscosity and thermal properties of rCDP were analyzed and compared with virgin CDP (vCDP). Effects of SIPE on rheological property and dyeability of rCDP were also investigated. (C) 2020 Elsevier Ltd. All rights reserved.