新型磷酸基缓凝剂的合成及性能评价

以尿素、亚磷酸和甲醛溶液为原料,以质子酸硫酸为催化剂,在一定温度下发生类曼尼希反应,采用一步法制备了一种新型结构磷酸基缓凝剂HN-101,其单分子结构含有4个磷酸根。通过净浆、砂浆和混凝土试验,考察了该缓凝剂与减水组分聚羧酸减水剂复配时的应用性能.结果表明:该缓凝剂具有耐黏土的特点,对机制砂具有良好的适应性,同时,该缓凝剂能大幅延长缓凝时间,并不影响水化后期混凝土的强度,对大体积混凝土具有潜在的应用价值。

Synthesis and performance evaluation of a new phosphate retarder

A phosphate retarder HN-101 with a new structure was prepared in one step by using urea,phosphorous acid and formaldehyde solution as raw materials and proton acid sulfuric acid as catalyst,with Mannich-like reaction under certain temperature.Its single molecular structure contains 4 phosphates.The application performance of this sample was tested with cement paste,cement mortar and concrete mixed with the PCE as the water-reducing component.The results showed that the HN-101 has the characteristics of clay resistance and good adaptability to machine-made sand.And also the HN-101 can greatly extend the retardation time without affecting concrete strength in the later stage of hydration.It would be beneficial to the application of large volume concrete.