一种具有抗泥作用的两性聚羧酸减水剂的低温合成工艺研究  

Synthesis of A Kind of Amphoteric Polycarboxylate Superplasticizer with Clay Tolerance at Low Temperature

作　　者：赵军丽[1,2] 邵华华 

机构地区：[1]武汉科技大学城市学院,湖北武汉430083 [2]中国地质大学(武汉)材料与化学学院,湖北武汉430074

出　　处：《化学与生物工程》2017年第6期45-50,64,共7页Chemistry & Bioengineering

基　　金：湖北省教育厅科学技术研究计划指导性项目(B2013243)

摘　　要：针对目前混凝土砂石中含泥量高的问题,以自制阳离子单体(MADA)、丙烯酸(AA)、异戊烯醇聚氧乙烯醚(TPEG)为单体,以30%H_2O_2-次磷酸钠(SHP)为氧化还原引发剂,在低温条件下水溶液中通过自由基共聚合成了一种两性聚羧酸减水剂(PCE)。以水泥净浆流动度为评价指标,确定最优合成工艺为:单体物质的量比n(AA)∶n(TPEG)∶n(MADA)为4.0∶1.0∶0.5、30%H_2O_2用量2.0%、m(H_2O_2)∶m(SHP)为2.5∶1、反应温度30℃、单体滴加时间3.0h、保温时间2.5h。采用FTIR表征了两性PCE的分子结构,采用凝胶渗透色谱(GPC)测试了两性PCE的分子量分布,其分子产率达到96.69%。水泥净浆流动度测试结果表明,当水灰比为0.29、两性PCE(M_w为20 180)折固掺量为水泥质量的0.15%时,水泥净浆初始流动度为292mm,60min后的流动度为295mm,具有较好的分散性和分散保持性;当300g水泥中泥土掺量高达5%时,净浆仍具有较好的分散性和分散保持性,表明两性PCE具有较好的抗泥作用。Aiming at the high clay content in concrete, using self-made cationic monomer（MADA）,maleic anhydride（AA） ,isoamyl alcohol polyoxyethylene ether（TPEG） as monomers, 30%H2 O2-sodium hypophosphite （SHP） as a redox initiator, we synthesized one kind of amphoteric polycarboxylate superplasticizer （PCE） through free radical copolymerization in an aqueous solution at a low temperature. Using cement paste fluidity as an evaluation index,the optimum synthetic conditions were obtained as follows：n（AA） ： n（TPEG） ： n（MADA） of 4.0 ： 1.0 ： 0.5, H2O2 （30 %） dosage of 2.0 %, m （H2 O2 ） ： m （SHP） of 2.5 ： 1, reaction temperature of 30 ℃ ,monomer adding time of 3.0 h,and holding time of 2.5 h. Molecular structure of amphoteric PCE was characterized by FTIR. Molecular weight distribution of amphoteric PCE was tested by GPC,and the molecular yield of amphoteric PCE reached 96.69 %. Results of the test of cement paste fluidity indicated that, when the addition amount of net amphoteric PCE（Mw=20 180） was 0.15% of cement mass,and water-cement ratio was 0.29,the paste had better dispersity and dispersion stability with the initial fluidity of 292 mm and the fluidity of 295 mm after 60 min. When 5% clay was added into 300 g cement,the paste still had better dispersity and dispersion stability,which indicated amphoteric PCE had excellent clay tolerance.

关 键 词：两性聚羧酸减水剂 30%H2O2-次磷酸钠 分散保持性 抗泥作用 

分 类 号：TQ463.25[化学工程—制药化工] TQ172