Itaconic acid

(1) The benchmark cement used in this study was produced by China United Cement Group Co., Ltd., (Beijing, China), and its chemical composition and physical properties are shown in Table 2. (2) Isopentenyl polyoxyethylene ether (IPEG, M_W = 2400 g·mol⁻¹, average degree of polymerization was produced by Jiahua Chemical Co., Ltd. (Jinhua, China) acrylic acid (AA), methacrylic acid (MAA), sodium methacrylate sulfonate (SMS), 2-acrylamide-2-methylpropane sulfonic acid (AMPS), and itaconic acid (IA) were all of chemical purity and purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China) ammonium persulfate (APS) was produced by Jinan Fengle Chemical Co., Ltd. (Jinan, China) Sodium hexametaphosphate (SH) was produced by Jining Shunyida Chemical Technology Co., Ltd. (Jining, China) deionized water (W) was used throughout the experiments. The chemical composition and physical properties of the cement are shown in Table 2.

Acrylonitrile (AN) with analytical grade was purchased from the Sinopharm Chemical Reagent Co. Ltd. (Shanghai, China) and purified by distillation at the temperature about 77 °C to remove the inhibitors. Itaconic acid and ascorbic acid with analytical grade were also provided by the Sinopharm Chemical Reagent Co. Ltd. (Shanghai, China), which were used without further purification. Deionized water was used as the solvent.