EPEG大单体聚合升温与其合成减水剂性能的关联

Correlation of EPEG macromonomer polymerization temperature rise and its synthetic water reducer performance

研究了几种乙烯氧基聚乙二醇EPEG大单体与丙烯酸接枝共聚合成聚羧酸减水剂,在相同条件下进行聚合反应,对EPEG型聚羧酸减水剂合成过程进行升温测试及聚合过程分析,使用凝胶渗透色谱法表征产物的相对平均分子量、分子量分布指数及转化率等结构参数,最后测试产物的水泥净浆流动度、混凝土材料的流动性以及硬化后的力学性能。试验结果表明:不同EPEG大单体聚合活性差异很大,大单体聚合快速升温期在15 min以内的聚合效果好。EPEG聚合放热升温曲线可以作为评价EPEG大单体活性的一种简单有效的方法,EPEG大单体聚合升温曲线与其合成聚羧酸减水剂应用性能二者间有很好的关联性。

Several ethyleneoxy polyethylene glycol(EPEG)macromonomers were studied in graft copolymerization with acrylic acid to obtain polycarboxylate water reducer.The polymerization reactions were carried out under the same conditions,and the synthesis process of EPEG-type polycarboxylate water reducer was subjected to temperature rise tests and analysis of the polymerization process.The molecular structural parameters such as relative average molecular weight,molecular weight distribution index and conversion rate of the product were characterized by gel permeation chromatography.Finally,the fluidity of cement paste,the flowability of concrete materials and the mechanical properties of the products after hardening were tested.The results show that the polymerization activity of EPEG macromonomers varies greatly,and the polymerization effect is good when the rapid heating period of macromonomer polymerization is within 15 min.The EPEG polymerization exothermic heating curve can be used as a simple and effective method to evaluate the activity of EPEG macromonomers,and there is a good correlation between the EPEG macromonomer polymerization heating curve and the application performance of its synthetic polycarboxylate water reducer.