降粘型聚羧酸减水剂结构与性能研究

Structure and properties of viscosity reducing polycarboxylate superplasticizer

以不同分子量异戊烯基聚氧乙烯醚、乙烯基三乙氧基硅烷、丙烯酸为原材料,设计制备了不同侧链密度和不同主链长度结构的降粘型减水剂(V-PCE)。通过净浆排空时间、净浆流变及混凝土试验研究,评估了的V-PCE对浆体流动性能的影响。结果表明,固定侧链长度不变,随着酸醚比的增大,分子的侧链密度逐渐降低,主链长度逐渐增大,电荷密度逐渐增大;固定酸醚比,随着侧链长度增大,主链长度减小,电荷密度逐渐降低。具有较长主链、短侧链、较低侧链密度及较高电荷密度的IPEC1200AA2.50和IPEG1200AA3.00具有优异的降粘效果。

A viscosity reducing water reducing agent(V-PCE)with different side chain densities and main chain length structures was designed and prepared using different molecular weights of isopentenyl polyoxyethylene ether,vinyl triethoxysilane,and acrylic acid as raw materials.The impact of V-PCE on the flowability of the slurry was evaluated through the study of the emptying time of the slurry,the rheological properties of the slurry,and concrete experiments.The results show that when the length of the side chain is fixed,with the increase of the ratio of acid to ether,the side chain density of the molecule gradually decreases,the length of the main chain gradually increases,and the charge density gradually increases.At a fixed acid-ether ratio,as the side chain length in-creases,the main chain length decreases,and the charge density gradually decreases.IPEG1200AA2.50 and IPEG1200AA3.00 with longer main chain,shorter side chain,lower side chain density and higher charge density have excellent viscosity reduction effect.