高寒高海拔地区混凝土用聚羧酸减水剂的合成及性能研究

Study on the synthesis and performance of polycarboxylic acid water-reducing agent for concrete in cold and high altitude areas

针对高寒高海拔地区混凝土含气量不足、气泡稳定性差的问题,以异戊烯醇聚氧乙烯醚(TPEG)、甲氧基聚乙二醇丙烯酸酯(MPEGA-600)、丙烯酸(AA)和对苯乙烯磺酸钠(SSS)为单体,在复合引发剂和巯基丙酸的作用下,利用水溶液自由基共聚制得聚羧酸减水剂。研究了酯醚比、酸醚比和n(SSS)∶n(TPEG)对合成减水剂性能的影响及其与不同水泥的适应性,并对比研究了在标准大气压和低大气压条件下减水剂对混凝土性能的影响。结果表明,所制备的减水剂具有高引气、高稳气和高适应性的特点,且当其Mw为82109,PDI为1.37时性能最佳。

According to the problem of insufficient air content and poor bubble stability of concrete in cold and high altitude areas,prenyl alcohol polyoxyethylene ether(TPEG),methoxypolyethylene glycol 600 acrylate(MPEGA-600),acrylic acid(AA)and sodium p-styrene sulfonate(SSS)are used as monomers to synthesize polycarboxylic acid water-reducing agent by the free radical copolymerization of aqueous solution under the combined action of composite initiators and mercaptopropionic acid.The effect of the molar ratio of MPEGA-600,AA and SSS to TPEG on the performance of synthetic water reducer and the adaptability of water-re-ducing agent to different cements were studied,and comparative study on the performance of water-reducing agent on concrete under standard atmospheric pressure and low atmospheric pressure conditions.The results show that the prepared polycarboxylic acid water-reducing agent has high air-introducing,high bubble stability,high adaptability,and the performance is the best when its Mw is 82109 and PDI is 1.37.