【摘要】 利用麦芽糊精合成出新单体麦芽糊精丙烯酸酯(ADE),然后通过自由基聚合将其接枝到减水剂分子上合成改性聚羧酸减水剂,并利用红外光谱表征了ADE和改性聚羧酸减水剂的合成,同时探究了聚羧酸减水剂的最佳合成条件。结果表明,当反应温度为70℃、反应时间(滴加时间)为2.5 h、引发剂质量分数为1.4%、甲基烯丙基聚氧乙烯醚(TPEG)和丙烯酸(AA)与ADE的物质的量比为1∶3∶1.2时,合成出的改性聚羧酸减水剂对水泥的分散和保持性能最好。同时通过与市售减水剂的性能对比,发现麦芽糊精改性聚羧酸减水剂对水泥的的分散和保持性能良好,后期也可以显著提高混凝土的强度。更多还原

【Abstract】 A new monomeric maltodextrin acrylate(ADE) was synthesized by using maltodextrin,and then it was grafted onto the water reducing agent molecule by free radical polymerization to synthesize a modified polycarboxylate water reducing agent,and the infrared spectrum was utilized.The successful synthesis of maltodextrin acrylate and modified polycarboxylate superplasticizer were characterized,and the optimal synthesis conditions of modified polycarboxylate superplasticizer were explored.The results showed that when the reaction temperature was 70 ℃,the reaction time(dropping time) was 2.5 hours,the amount of the initiator was 1.4%,and the molar ratio of methallyl polyoxyethylene ether,acrylic acid and ADE was 1∶3∶1.2,the synthesized modified polycarboxylic acid water reducing agent had the best dispersion and retention performance for cement.At the same time,by comparing with commercially available water reducing agents,the maltodextrin modified polycarboxylate water reducing agent not only had good dispersion and retention properties,but also improved the strength of concrete significantly in the later stage.更多还原