MAPEG-HEA-SMAS三元共聚物高效减水剂的制备与性能

Preparation and Performance of Polycarboxylate Terpolymer Superplasticizer MAPEG-HEA-SMAS

摘要:

以马来酸聚乙二醇单酯（MAPEG）、丙烯酸羟乙酯（HEA）、甲基丙烯磺酸钠（SMAS）为原料通过共聚反应制得MAPEG-HEA-SMAS三元共聚聚羧酸高效减水剂，考察了单体摩尔比、引发剂用量、反应温度等合成条件对减水剂性能的影响，并用IR对减水剂的分子结构进行表征，以GPC表征减水剂的分子量及分布，通过SEM观察了掺入减水剂的水泥石微观结构。结果显示，当n（MAPEG）：n（MA）：n（SMAS）=1.0：1.0：1.5，聚合反应温度为88℃，聚合反应时间为7.5h，引发剂用量为单体总质量的3.5%，PEG相对分子质量为1000时，合成的减水剂综合性能良好。当其掺量为0.45%（质量分数）时，水泥净浆初始流动度达308mm。GPC分析显示减水剂平均分子量Mn=7752，分散系数Mw/Mn=2.091，SEM分析结果显示聚羧酸减水剂使水泥石大孔率降低,结构更密实。

Abstract:

Polycarboxylate terpolymer superplasticizer of MAPEG-HEA-SMAS was sunthesized by copolymerization with esterification intermediate（MAPEG），hydroxyethyl acrylate（HEA）and sodium methallyl sulfonate（SMAS）as main raw materials. The influence of molar ratio of monomer，dosage of initiator，reaction temperature and reaction time on the copolymerization were investigated. The structure was characterized by IR. Relative molecule mass and its distribution of superplasticizer is measured by GPC, and the microstructure of cement is characterized by SEM. The results show that when the molar ratio of MAPEG to MA to SMAS is 1.0:1.0:1.5，the polymerization reaction temperature is 88℃,the polymerization reaction time was 7.5h, the dosage of initiator is 3.5% of total monomer mass and the relative molecule of PEG mass is 1000,the superplasticizer prepared under this condition would exhibit good performance.The original fluidity of cement grout can reach 308mm with 0.45% percentage mass content of this superplasticizer(mass fraction).GPC shows that the mean molecular weightMn)and polydispersity Mw/Mn of the superplasticizer is 7752 and 2.091.SEM shows the amount of macropors of cement added with the polymerization reduce, and the crystals grow more dense.