缩聚型聚羧酸减水剂的合成及性能研究

Performance Evaluation of Polycarboxylate Superplasticizer Synthesized through Condensation Polymerization

通过硫酸催化下的邻羟基苯甲酸、苯酚聚氧乙烯醚和甲醛之间的缩聚反应,合成了一种新型聚羧酸减水剂。在不同反应时间下使用GPC对聚合物转化率和分子量进行测试,得到了反应的动力学曲线。此外,研究了酸醚比、温度、甲醛用量和硫酸用量对聚羧酸性能的影响。最佳合成条件为:酸醚比4,温度115℃,甲醛105%,硫酸40%。合成的聚羧酸有较高的减水率,能提高混凝土的抗压强度。

A novel polycarboxylate superplasticizer based on condensation polymerization of 2-hydroxybenzoic acid,phenol poly（ethylene glycol） ether and formaldehyde catalyzed by sulfuric acid was synthesized. The polymer conversionand molecular weight at different time were measured by GPC, a kineticdiagramwas plotted. The influence of acid/etherratio, reaction temperature, the amount of formaldehyde and sulphuric acid on the performance of the synthesized polymerswas studied. The optimal condition was found as follows： acid/ether ratio of 4, reaction temperature of 115 ℃, 105% offormaldehyde and 40% of sulphuric acid. The resultant polymer has a high water-reducing rate, can improve compressionstrength of concrete.