缓释型聚羧酸减水剂的合成及性能研究

Study on synthesis and properties of slow release polycarboxylate superplasticizer

以异戊烯基聚氧乙烯醚(TPEG-2400)、丙烯酸羟乙酯(HEA)和反丁烯二酸(FA)为共聚单体,以抗坏血酸-双氧水为自由基引发体系以三巯基丙酸(3-MPA)为分子质量调节剂,合成了一种三元共聚缓释型聚羧酸减水剂。通过水泥净浆经时流动度研究其缓释规律,并筛选最佳合成条件为:设计理论固含量40%,单体物料比m(TPEG-2400)∶m(HEA)∶m(FA)=100∶15∶4,引发剂用量为TPEG-2400质量的1.15%,双氧水用量为TPEG-2400质量的0.7%,常温下滴加时间2 h,保温时间1 h。混凝土试验结果表明,合成的缓释型聚羧酸减水剂具有良好的保坍性能和施工性能,对混凝土的力学性能没有明显影响。

A kind of ter-polyester polycarboxylate superplasticizer with slow-release properties has been prepared from HEA （hydroxyethyl acrylate）, FA （fumaric acid） and TPEG-2400 （isopentenyl polyoxyethylene ether） under the condition of ascorbic acidhydrogen peroxide free radical initiation system and three mercapto propionic acid （3-MPA） as the molecular weight regulator. The release rules was studied by the fluidity of cement paste, and the optimal synthesis conditions is theory solid content of 40%, material ratio is m（TPEG-2400）：m（HEA）：m（FA）=100：15：4,initiator dosage 1.15% for the mass of TPEG-2400,hydrogen peroxide content 0.7% for the mass of TPEG-2400,druping 2h at room temperature,holding time 1 h. A good working performance and well released properties was showed by the concrete experimental test,and has has no obvious influence on the mechanical properties of concrete.