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.

通过酯交换反应制备了可以与对苯二甲酸双（羟乙基）酯（BHET）共聚的5-磺基双（羟乙基）-间苯二甲酸钠（SIPE）共聚单体。 5-磺基间苯二甲酸二甲酯钠（SIPM）与乙二醇（EG）的反应。然后将获得的SIPE与BHET进行缩聚反应，然后在氮气气氛下用过量的EG作为糖酵解剂，并用乙酸锌（Zn（Ac）2）作为催化剂，从废弃的PET纤维解聚中提取BHET，得到再生的阳离子可染聚酯（rCDP）。分析了rCDP的化学结构，热性质，特性粘度和热性质，并将其与原始CDP（vCDP）进行了比较。还研究了SIPE对rCDP的流变性和可染性的影响。