论文部分内容阅读
以PEG(聚乙二醇)、MA(马来酸酐)、IA(衣康酸)和SMAS(甲基丙烯磺酸钠)为共聚单体,制备PEGMMA(马来酸聚乙二醇单酯)-MA-IA-SMAS四元共聚减水剂;然后将其用于混合土配方中,并以水泥净浆流动度为考核指标,采用单因素试验法优选合成减水剂的最优方案。结果表明:当减水剂中n(PEG)∶n(MA)∶n(IA)∶n(SMAS)=1∶3.8∶0.5∶1.0、酯化温度为105℃、酯化时间为4 h、w(引发剂)=12.5%(相对于单体总质量而言)、w(催化剂)=4%(相对于PEG和MA总质量而言)、聚合温度为80℃和聚合时间为7.5 h时,合成的减水剂和改性混凝土[w(减水剂)=0.33%]具有相对较好的综合性能;此时,水泥净浆初始流动度(278 mm)相对最大,并且混凝土减水率为28.6%、含气量为2.1%以及28 d压缩强度为49.6 MPa。
PEGMMA (maleic acid polyethylene glycol monoester) was prepared with PEG (polyethylene glycol), MA (maleic anhydride), IA (itaconic acid) and SMAS (sodium methallyl sulfonate) as comonomers -MA-IA-SMAS ternary copolymer. Then, it was used in the mixed soil formulation. The fluidity of cement paste was taken as the assessment index, and the optimal scheme of synthesizing water reducer was optimized by single factor test. The results showed that when the esterification temperature is 105 ℃, the esterification time is 4 h, the concentration of n (PEG): n (MA): n (IA): n (SMAS) = 1: 3.8: 0.5:1.0, w (initiator) = 12.5% (relative to the total monomer mass), w (catalyst) = 4% with respect to the total mass of PEG and MA, the polymerization temperature of 80 ° C and the polymerization time of 7.5 h , The synthetic superplasticizer and modified concrete [w (water reducer) = 0.33%] have a relatively good overall performance; at this time, the initial fluidity of cement paste (278 mm) is relatively maximum, and the concrete water reduction rate Of 28.6%, gas content of 2.1% and compressive strength of 49.6 MPa at 28 days.