复合型氧化还原引发体系聚羧酸高性能减水剂的常温合成

The conventional temperature synthesis of high performance polycarboxylates superplasticizer by the oxidation-reduction composite system

以2-甲基烯丙基聚氧乙烯基醚（HPEG）、丙烯酸（AA）、丙烯酸甲酯（MA）为单体,过硫酸铵（APS）和维生素C-双氧水（Vc-H2O2）复合引发,巯基乙酸（TGA）为链转移剂,采用水溶液自由基聚合法合成了聚羧酸减水剂（PC-1）.通过实验,确定合成该减水剂的最佳工艺为：在常温下（20～40℃）,原材料质量比：m（HPEG）∶m （AA） =8.5∶1.0;MA用量为大单体质量的1.5％;引发剂m（Vc-H2O2）∶m （APS） =0.9∶1.0,m （H2O2）∶m （Vc） =5.5∶1.0,引发剂总量为大单体质量的1.2％; TGA用量为大单体质量的0.4％;反应时间3h.合成的聚羧酸减水剂具有更好的减水性、保坍性、分散性及和易性.

A new polycarboxylate superplasticizer（PC-1） was synthesized with 2-methyl allyl polyoxyethylene ether（HPEG）,acrylic acid （AA） and methyl acrylate（MA） as monomers,using ammonium persulfate（APS） and Vitamin C-hydrogen peroxide （Vc-H2O2） as complex initiator,and thioglycolic acid（TGA） as chain transfer agent.The best synthesis condition for the radical polymerization was that the mass ratio of raw materials was HPEG∶AA was 8.5∶1.0,the initiator was composed of （Vc-H2O2）∶APS=0.9∶1.0,H2O∶Vc=5.5∶1.0,the dosage of MA,total initiator and TGA were 1.5％,1.2％,0.4％ of the HPEG mass,the reaction time was 3 h at room temperature（20～40 ℃）.The excellent polycarboxylate superplasticizer had high water-reducing ratio,good slump maintenance,dispersing ability and workability.