Low-cost synthesis of high-performance polycarboxylic ether by Co2+-, Ni2+- and Zn2+-catalyzed H2O2-NaHSO3 initiation system

Autor: Haijun Yang, Quan Xiang Feng, Xian Yan Ren, Heng Tong Zhang, Shu Dong Lin, Cai Lin Liu
Rok vydání: 2021
Předmět:
Zdroj: Chemical Papers. 75:3421-3428
ISSN: 1336-9075
2585-7290
DOI: 10.1007/s11696-021-01573-3
Popis: As a new type of high-performance water-reducing agent, polycarboxylate ether (PCE) has excellent properties such as small dosage and high water reduction rate. However, it is still necessary to develop a synthetic process to improve the performance of PCE at a low cost. In this paper, Co2+-, Ni2+- or Zn2+-catalyzed H2O2-NaHSO3 redox initiation system is designed as a new cost-effective composite initiator system to synthesize PCE(Co2+), PCE(Ni2+) and PCE(Zn2+). The synthesized PCEs were characterized by FTIR, GPC, Zeta potential, XRD, TG, SEM and HPLC. Compared with PCE0 synthesized by H2O2-NaHSO3 system without metal ion catalyst, FTIR and GPC data show that the molecular weights of PCE(Co2+), PCE(Ni2+) and PCE(Zn2+) were slightly reduced without any functional group type changed. When the double bond retention rate of isopentenol polyoxyethylene ether (TPEG) is 94.34%, the conversion rate of TPEG catalyzed by Co2+, Ni2+ or Zn2+ is up to 93.82%, which is much higher than 77.34% of PCE0. Compared with PCE0, PCE(Co2+), PCE(Ni2+) and PCE(Zn2+) have better dispersion and retention abilities, a 51-mm larger fluidity and a bigger early hydration rate of cement slurries. Interestingly, the water reduction rates of PCE(Co2+), PCE(Ni2+) and PCE(Zn2+) are 13.7%-25.3% higher than that of PCE0.
Databáze: OpenAIRE
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