以双氧水（H₂O₂）与亚硫酸氢钠（NaHSO₃）为引发体系，硫酸钴（CoSO₄）为催化剂，异戊烯醇聚氧乙烯醚-2400（TPEG-2400）和丙烯酸（AA）为单体，二元共聚合成聚羧酸减水剂（PCA）。通过单因素及正交试验优化的制备条件为：n（AA）：n（TPEG-2400）=4.4：1，巯基乙酸（TGA）质量分数为0.39%，CoSO₄·7H₂O质量分数为0.1%，NaHSO₃质量分数为0.4%，n（H₂O₂）：n（NaHSO₃）=8：1，反应温度为50℃，反应时间为3.5 h。与H₂O₂-NaHSO₃引发体系合成的PCA0相比，H₂O₂-NaHSO₃-CoSO₄引发体系合成的PCA1具有较低的分子质量及较高的单体转化率；PCA1折固掺量为0.15%、水灰比为0.29时，初始水泥净浆流动度超过290 mm（较PCA0提高了50 mm以上），具有更加优异的性能。

A binary polycarboxylic acid water reducer (PCA) is gained through binary copolymerization between isopentenyl polyoxyethylene ether-2400 (TPEG-2400) and acrylic acid (AA) by using hydrogen peroxide (H₂O₂) and sodium bisulfite (NaHSO₃) as the initiating system,cobalt sulfate (CoSO₄) as the catalyst.The preparation conditions are optimized by single factor and orthogonal tests as follows:n(AA):n(TPEG-2400)=4.4:1,the mass fractions of thioglycollic acid (TGA),CoSO₄·7H₂O and NaHSO₃ are 0.39%,0.1%,and 0.4% of the total monomer mass,respectively,n(H₂O₂):n(NaHSO₃)=8:1,the reaction is carried out at 50℃ for 3.5 hours.Compared with PCA0 which is synthesized by H₂O₂-NaHSO₃ initiating system,PCA1 synthesized under the initiation of H₂O₂-NaHSO₃-CoSO₄ has smaller molecular weight and higher monomer conversion rate;When the solid content of PCA1 is 0.15% and the water-cement ratio is 0.29,the cement paste fluidity exceeds 290 mm,50 mm more than that of PCA0,showing a superior performance.

冯全祥(1991-),男,硕士研究生,主要从事聚羧酸减水剂的合成与应用研究,1401782440@qq.com