聚羧酸减水剂的室温合成研究

（西南科技大学 材料科学与工程学院，四川 绵阳  621010）

    摘要：采用过氧化叔丁醇（TBHP）与次硫酸氢钠甲醛（SFS）为引发体系，选用3种聚醚类大单体分别与丙烯酸（AA）进行自由基聚合，实现了室温合成聚羧酸高效减水剂（PCA）。单因素及正交试验优化合成工艺为：n（AA）∶n（聚醚大单体）＝4∶1，巯基乙酸用量为单体总质量的0.45%，TBHP用量为单体总质量的0.18%，n（TBHP）∶n（SFS）＝1∶1，反应温度25 ℃，反应时间2 h。TBHP-SFS室温引发体系与3种大单体均具有好的适应性，合成的3种PCA具有优异的性能。当3种PCA的折固掺量为0.2%、水灰比为0.29时，水泥净浆流动度均大于300 mm。

    关键词：聚羧酸减水剂；室温合成；结构表征；水泥净浆；水泥砂浆

    中图分类号：TU528.042+.2        文献标识码：A        文章编号：1001-702X（2018）09-00

 

Study on synthesis of polycarboxylate superplasticizer at room temperature

FENG Quanxiang，HU Qing，LIU Cailin，REN Xianyan，YANG Haijun，WANG Yuping

（School of Materials Science and Engineering，Southwest University of Science and Technology，Mianyang 621010，China）

   Abstract：The polycarboxylate superplasticizer（PCA） can be synthesized at room temperature when tertbut-yl hydroperoxide（TBHP）-sodium formaldehyde sulfo-xylate（SFS） initiator system was used，according to the free radical polymerization of three kinds of polyether macromonomer and acrylic acid（AA）. The optimized synthesis conditions were confirmed by single factor and orthogonal experiments. The molar ratio of AA to polyether macromonomer was 4∶1，the dosage of mercaptoacetic acid and TBHP is 0.45% and 0.18% of total monomers，respectively；the molar ratio between TBHP and SFS is 1∶1，the reaction temperature is 25 ℃，and the reaction lasts for 2 h. The TBHP-SFS room-temperature initiator system had good adaptability with the three polyether macromonomers，and the synthesized three kinds of PCA show excellent performance. When 0.2% of PCA and 0.29 water-cement ratio were used，the fluidity of cement paste exceeded 300 mm.

    Key words：polycarboxylate superplasticizer，room temperature synthesis，structural characterization，cement paste，cement mortar