醚型聚羧酸系减水剂的合成及性能研究

Synthesis and performance of the ether-type polycarboxylate superplasticizers

烯丙基聚氧乙烯醚、顺酐、丙烯酸、丙烯酰胺为共聚单体,过硫酸铵为引发剂,通过自由基溶液聚合制得四元醚型聚羧酸减水剂。实验表明,最佳工艺条件为n(APEG):n(MA):n(AM):nn(AA)=1:2:1:1.5,引发剂用量为4%.该减水剂在折固掺量为0.14%,水灰比为0.29时,水泥的净浆流动度达到336mm,1h后为308mm。放置数月后减水剂稳定性不变。对不同厂家的四种水泥进行了净浆流动度试验,水泥适应性不佳但可调整掺量得到合适流动度。通过FTIR分析,表明MA、AM、AA均接入主链中,APEG接在AM上形成侧链。并依此得出了自制减水剂的分子式。

A kind of ether-type polycarboxylate superplasticizers was synthesized by aqueous solution free radical polymerization using allylic polyethylene glycol （APEG）, methyl acrylate（MA）, acrylic acid（AA）, acrylamide （AM） as comonomers and ammonium persulfate （APS） as initiator. The results showed that the optimum reaction condition are as follows： n（APEG）： n（MA）： n（AA）： n（AM） =1： 2： 1： 1.5, and the dosage of ammonium persulfate is 4% of total monomers by mass. The fluidity of cement paste reached 336 mm at the solid dosage of 0.14% and 308 ham lh later when used in cement system with W/C ratio of 0.29. The stability of this ether-type polycarboxylate quadripolymer superplasticizer remained well after several months. The adaptability of the superplasticizers to four kind cements was researched by the testing of fluidity of cement paste. The result showed poor adaptability of the ether-type superplasticizers but it can be adjusted by increasing the solid dosage. The molecule structure of the synthetic product has been given by FTIR and showed that the comonomers （MA, AA, AM） have copolymerized as main chain and APEG as side chain.