EPEG型保坍聚羧酸减水剂的合成及性能研究

Study on synthesis and properties of EPEG slump retention type plasticizer

选用新型高活性大单体EPEG与丙烯酸、羟乙酯等小单体反应,通过正交试验研究合成工艺参数对聚羧酸减水剂性能的影响。结果表明,最佳合成工艺为:酸醚比2.0,酯醚比3.0,反应温度20℃,底料浓度60%,链转移剂、Vc、Na_(2)S_(2)O_(8)、H_(2)O_(2)用量分别为EPEG质量的0.6%、0.3%、0.6%、1.5%,A料、B料滴加时间分别为30、60 min。对按最佳工艺合成的EPEG型保坍聚羧酸减水剂进行红外光谱分析、水泥净浆和混凝土性能测试表明,合成减水剂具有优异的分散和保坍性能,同时对混凝土强度无不良影响。

A new type of high activity EPEG monomer was selected to react with acrylic acid,hydroxyethyl ester and other small monomers,and the influence of various factors on the performance of plasticizer was explored by orthogonal experiment.The experimental results show that the optimal synthesis process is as follows:acid-ether ratio 2.0,ester ether ratio 3.0,reaction temperature 20℃,base concentration 60%,chain transfer agent dosage 0.6%,initiation system Vc dosage 0.3%,Na_(2)S_(2)O_(8) dosage 0.6%,H_(2)O_(2) dosage 1.5%,drop time of material A 30 min,material B 60 min.The optimum synthetic product was tested by infrared spectrum,fluidity of cement slurry and concrete performance,and the synthesized polycarboxylic acid superplasticizer has excellent dispersion and slump retaining properties,and has no adverse effect on concrete strength.