【摘要】 以甲基丙烯酸(MAA)、甲基丙烯磺酸钠(MAS)、甲氧基聚乙二醇甲基丙烯酸酯(PMA45)为共聚单体,以过硫酸铵为引发剂,合成了一系列聚羧酸高效减水剂.通过测定硬化砂浆早期强度以及采用扫描电镜观察早期水泥石形貌,研究了不同原料配比对聚羧酸高效减水剂早强性能的影响.结果表明,聚羧酸高效减水剂早强性能随着PMA45用量的增加先增大后减小,随着MAA、MAS用量的增加及减水剂相对分子质量的减小而增大,即具有适中的聚乙二醇侧链密度、较高的羧酸根及磺酸根含量、较低的相对分子质量的聚羧酸分子具有较好的早强性能.更多还原

【Abstract】 A series of polycarboxylate superplasticizers were synthesized with methacrylic acid(MAA),sodium methylacrylamide(MAS) and methoxy polyethylene glycol methacrylate(PMA45) as monomers,and ammonium persulfate(APS) as an initiator.Then,the effects of raw material proportion on the early-strength performance of polycarboxylate superplasticizers were investigated by measuring the early strength of harden mortar and by using a scanning electron microscope to observe the morphology of early cement stone.The results show that the early-strength performance of the superplasticizers first increases and then decreases with the increase of the dosage of PMA45,and increases with the increase of the dosages of MAA and MAS as well as with the decrease of the relative molecular mass of the superplasticizers,which means that the superplasticizers with optimal density of side chain(polyethyleneglycol),high contents of carboxylate and sulfonate,and low relative molecular mass are of excellent early-strength performance.更多还原