新型羧酸类接枝聚合物保坍剂的清洁生产工艺、性能与工程应用

The Process for the Cleaner Production, Performance and Engineering Applications of Novel Carboxylic Grafted Polymeric Concrete Slump Retaining Agent

以混凝土外加剂分子设计原理为指导,以绿色化学为基础,研究了新型羧酸类接枝聚合物保坍剂的清洁制备工艺.结果表明,以复合引发剂(K2S2O8+30%H2O2)替代BPO(过氧化苯甲酰)引发剂,以水替代有机溶剂,通过一釜多步串联反应,实现了混凝土保坍剂的清洁生产,彻底消除了传统反应性高分子生产工艺对环境的污染.采用该工艺合成的产品在较低掺量的情况下(为水泥重量的0.05%)与传统的萘系减水剂复合使用,具有良好的保塑效果:对于初始坍落度为12～14cm的低流动性混凝土,1h坍落度保持率基本在85%左右;对于初始坍落度为19～24cm的大流动性混凝土,新拌混凝土坍落度2h基本不损失.该产品并已在连云港田湾核电站、江苏润扬长江公路大桥得到了很好的推广应用.

Based on green chemistry and molecular design theory of concrete admixture, the process for the cleaner production of novel carboxylic grafted polymeric concrete slump retaining agent has been studied. The results show that the cleaner production of concrete polymeric concrete slump retaining agent is achieved by using multistage series reactions, water to replace organic solvent and complex initiator (K2S2O8+30%H2O2) to replace toxic BPO in a still. It avoids the environmental pollution caused by the process for the production of traditional reactive polymer. The product made by this method showed an excellent slump retaining ability by the addition of very low dosage of the grafted copolymer mixed with naphthalene sulphonatedformaldehyde condensate whether for small slump concrete or high fluidity concrete. From the results of this research, the slump loss of cement paste and concrete could be controlled effectively by the addition of 0.05% of the copolymer. The said product has been successfully used in Tianwan Nuclear Power Plant and the Jiangsu Runyang Yangtze River Highway Bridge.