EPEG型聚羧酸减水剂的合成及应用性能研究

Study on the synthesis and application performance of EPEG type polycarboxylate superplasticizer

采用EPEG和AA为共聚单体,以双氧水、Vc和亚铁离子型催化剂为引发体系,以巯基丙酸为链转移剂合成了一种EPEG型聚羧酸减水剂PCE-001,研究了不同合成因素对减水剂分散性的影响,并评价了PCE-001的应用性能。结果表明,PCE-001的最佳合成工艺为:酸醚比为4.0,巯基丙酸用量为单体总质量的0.5%,釜底丙烯酸用量为丙烯酸总质量的20%,A液滴加时间为30 min,B液滴加时间为40 min,液碱用量为单体总质量的4%。性能测试结果表明,相较HPEG型PCE,PCE-001除具有更好的分散性和分散保持性外,还具有更优异的和易性与更稳定的含气量保持性;但对于高强度等级混凝土,PCE-001会延长混凝土的排空时间。

Using EPEG and acrylic acid as reactant,H2O2,Vc and ferrous ion catalyst as initiating system,mercaptopropionic acid as chain transfer agent,an EPEG type polycarboxylate superplasticizer PCE-001 was synthesized.The effects of different synthetic factors on dispersion of polycarboxylic acid were investigated and the application performance of PCE-001 was evaluated comprehensively.The results indicate that the synthesis process of PCE-001 is as follows,the ratio of acid to ether is 4.0,the dosage of mercaptopropionic acid was 0.5%of the total monomer mass,the amount of acrylic acid at the bottom of the kettle is 20%of the total acrylic acid.Solution A was added dropwise for 30 min,solution B for 40 min,and the liquid alkali dosage was 4%of the total monomer mass.Performance tests show that PCE-001 not only exhibits better dispersion and dispersion retention property in comparison to HPEG type PCE,but shows better workability and more stable gas retention as well.However,for high grade concrete,PCE-001 will increase the emptying time of concrete.