新型聚羧酸保坍剂的制备及作用机理研究  

Research on Synthesis and Mechanism of a Novel Polycarboxylate Slump-retaining Agent

作　　者：刘冠杰[1] 任建国[1,2] 王自为[1,2] 裴继凯[1,3] 

机构地区：[1]山西大学化学化工学院,山西太原030006 [2]山西大学混凝土外加剂技术研究中心,山西太原030006 [3]山西山大合盛新材料股份有限公司,山西太原030006

出　　处：《山西大学学报（自然科学版）》2016年第2期269-275,共7页Journal of Shanxi University(Natural Science Edition)

基　　金：山西山大合盛新材料股份有限公司与山西大学合作项目(批准日期2013-09-25)

摘　　要：报道了一种新型聚羧酸保坍剂(HS-HPA)的制备方法,并研究了该保坍剂在混凝土中以皂化反应为基础,缓慢释放羧基的作用机理。首先以甲基烯丙基聚氧乙烯醚为大单体,以丙烯酸和丙烯酸羟丙酯为小单体,在引发剂过硫酸铵和链转移剂巯基乙酸作用下,按照一定的单体比例,聚合制得了一种新型聚羧酸保坍剂。进行了水泥净浆和混凝土实验,结果显示该聚羧酸保坍剂的保坍性能明显较优,在使用过程中与普通的聚羧酸减水剂进行复配,将大大提高混凝土的坍落度保持能力。此外,为研究聚羧酸保坍剂的作用机理,设计实验模拟了其在水泥浆体碱性环境中发生的皂化反应,通过测定保坍剂溶液电导率变化,得出保坍剂皂化速率与保坍性能之间的关系,验证了保坍剂的作用机理。A new preparation method of polycarboxylate slump-retaining agent（HS-HPA）has been reported,and the mechanism of HS-HPA which is based on saponification reaction in concrete and then releases carboxyl slowly has been particularly studied.The new polycarboxylate slump-retaining agent is prepared via polymerization reaction according to certain proportion of monomer with methyl allyl polyethenoxy ether as macromonomer,acrylic acid and hydroxypropyl acrylate as monomer,in the initiator of ammonium persulfate as initiator and mercaptoacetic acid as the chain transfer agent.The experiment of cement paste and concrete is carried on.The experimental results show that the polycarboxylate slump-retaining agent has obvious advantages in the slump retention properties.The polycarboxylate slump-retaining agent can significantly improve the slump retention capability of the ordinary polycarboxylate superplasticizer when used mixedly.In addition,to study the mechanism about polycarboxylate slump-retaining agent in concrete,the experiment is designed to simulate the saponification reaction occurring in the alkaline environment of cement paste.In this experiment,the relationship between slump-retaining agent saponification rate and slump retention properties is concluded according to the determination of conductivity change of the concrete slump-retaining agent solution,and the mechanism of the polycarboxylate slump retaining agent in concrete is verified.

关 键 词：聚羧酸保坍剂 保坍性能 皂化速率 作用机理 

分 类 号：TU528.042.2[建筑科学—建筑技术科学]