多孔型高吸水树脂对水泥净浆流动性能的影响

Effect of Porous Super Absorbent Polymer on Flowability of Cement Paste

为稳定掺入高吸水树脂(SAP)水泥基材料的流动性能,采用反相悬浮聚合法制备了多孔型聚丙烯酸/丙烯酰胺SAP.利用扫描电子显微镜(SEM)观测SAP的微观形貌,通过傅里叶红外光谱(FTIR)分析SAP的分子结构,用“茶袋法”测试SAP的吸液性能,并通过流动度试验研究了非多孔型及多孔型SAP对水泥净浆流动度经时变化的影响.结果表明:多孔型SAP具有微米级连通孔结构,能够有效促进吸水速率,达到吸水平衡只需1 min内;当通过额外引水保持水泥净浆初始流动度相同时,多孔型SAP的掺入对水泥净浆流动度的经时损失影响最小.

To stabilize the flowability of cement-based materials mixed with super absorbent polymer(SAP),the porous poly(acrylic acid/acrylamide)SAP was prepared by inverse suspension polymerization.The microscopic morphology and the molecular structure of the SAP were observed by scanning electron microscope(SEM),and Fourier infrared spectroscopy(FTIR),respectively.And the liquid absorbing properties of the SAP were determined by using tea bag method.In addition,the effect of non-porous and porous SAP on the fluidity loss of cement paste was studied through fluidity tests.The results show that the porous SAP with micro porous structure can effectively promote its water absorption rate,and it takes only 1 min to reach the water absorption balance.When the initial fluidity is maintained by additional water,the addition of porous SAP has the least effect on the fluidity loss of the paste over time.