新型含苯环聚羧酸系减水剂的制备与性能

用烯丙基聚氧乙烯醚(APE)、丙烯酸(AA)、甲基丙烯磺酸钠(SMAS)和阿魏酸(FA)作为反应单体,在过硫酸铵(APS)引发下通过水溶液自由基共聚反应制备了一种新型含苯环聚羧酸系减水剂(FPC)。当n(APE)∶n(AA)∶n(SMAS)∶n(FA)=1∶5∶0.3∶0.15时,在反应温度为85℃、反应时间为4 h、引发剂APS用量为总单体质量的3%时得到的FPC性能最佳。FPC的主要特点是对含泥水泥具有较强的适应性。实验结果表明,FPC的折固掺量为0.2%时,含泥质量分数10%的水泥净浆流动度可达308 mm,初凝时间和终凝时间分别达430 min和502min,减水率可达33.2%;扫描电子显微镜(SEM)和水泥胶砂强度检测结果表明,FPC可使水泥石更加紧密均质,可以明显提高硬化水泥砂浆的抗压强度。

Preparation and Properties of New Type Polycarboxylate Superplasticizer Included Benzene Ring

A new polycarboxylate superplasticizer(FPC) was synthesized by free radical copolymerization of acrylic allyl polyoxyethylene ether(APE),acid(AA),sodium methallyl sulfonate(SMAS) and ferulic acid(FA) using ammonium persulfate(APS) as initiator.The optimum FPC was obtained when the molar ratio of APE,AA,SMAS and FA was 1∶5∶0.3∶0.15 using 3% APS by monomers′ total mass at 85 ℃ for 4 h.The remarkable feature of FPC is that it has the strong adaptability to mud cement.The application results show that the fluidity of cement paste can reach 308 mm,and the initial and final setting time is 430 min and 502 min,respectively,and the water-reducing rate is 33.2% when FPC solid dosage is 0.2% and mud content is 10%.The results of SEM and compressive strength show that FPC can improve the density and uniformity of the hardened cement paste,hence the significantly improved compressive strength of hardened cement mortar.