摘要
以4-羟丁基乙烯基聚氧乙烯醚(VPEG)为大单体,丙烯酸(AA)、甲基丙烯酸(MAA)和甲基丙烯磺酸钠(SMAS)为主要共聚单体,以巯基乙酸(TGA)为链转移剂,在H2O_(2)/维生素C(VC)的氧化-还原引发体系下,通过自由基聚合反应合成了VPEG-降黏型聚羧酸高性能减水剂PCE-J,探究了酸醚比、MAA用量、SMAS用量等对合成减水剂性能的影响,得到最适合成工艺为:反应温度为20℃,酸醚比为3.5∶1,SMAS、MAA、H2O_(2)和TGA用量分别为VPEG的0.1%、2%、0.7%和0.6%(质量分数),A、B料液滴加时间分别为30、40 min。将PCE-J与市售降黏型减水剂PCE-S在水泥净浆流动度、混凝土的降黏性能(T50时间、排空时间)和水泥胶砂试块抗压强度等方面进行对比分析,得出PCE-J对水泥具有优异的分散性能,水泥净浆流动度高达305 mm,对混凝土具有优异的降黏效果,混凝土排空时间、T50时间分别为4.1和5.7 s,能显著提高水泥试块的抗压强度,28 d水泥试块抗压强度高达67.1 MPa。
Using 4-hydroxybutyl vinyl polyoxyethylene ether(VPEG)as macromonomer,acrylic acid(AA),methacrylic acid(MAA)and sodium methallyl sulfonate(SMAS)as comonomers,and thioglycolic acid(TGA)as chain transfer agent,VPEG-viscosity-reducing polycarboxylate superplasticizer PCE-J was synthesized by free radical polymerization under the redox initiation system composed of H 2O_(2)/vitamin C(V C).The effects of synthesis process condition on the properties of the synthesized superplasticizer were investigated.The most suitable synthesis process condition was obtained as follows.The reaction temperature was 20℃.The ratio of acid to ether was 3.5∶1.The amount of SMAS,MAA,H 2O_(2) and TGA was 0.1 wt%,2 wt%,0.7 wt%and 0.6 wt%of VPEG,respectively,and the addition time of A and B was 30 min and 40 min,respectively.The PCE-J and the commercially available viscosity-reducing superplasticizer PCE-S were compared and analyzed in terms of cement paste fluidity,concrete viscosity reduction performance(T50 time,emptying time)and cement test block strength performance.It is concluded that PCE-J has excellent dispersion performance for cement,cement paste fluidity is as high as 305 mm,and has excellent viscosity reduction effect on concrete.The concrete emptying time and T50 time are 4.1 s and 5.7 s,respectively,which can significantly improve the compressive strength of cement test blocks.The compressive strength of 28 d cement test blocks is as high as 67.1 MPa.
作者
周俊
杨睿
王稚阳
谢贵明
ZHOU Jun;YANG Rui;WANG Zhiyang;XIE Guiming(College of Chemistry and Chemical Engineering,Guizhou University,Guiyang 550025,China;Guizhou Provincial Key Laboratory of Green Chemical and Clean Energy Technology,Guiyang 550025,China)
出处
《功能材料》
CAS
CSCD
北大核心
2023年第11期11221-11229,共9页
Journal of Functional Materials
基金
国家自然科学青年基金项目(52102015)
贵州大学培育项目([2020]64)。
关键词
VPEG
聚羧酸高性能减水剂
降黏
合成
抗压强度
VPEG
polycarboxylate superplasticizer
viscosity reduction
synthesis
compressive strength
