机械化学法合成聚羧酸减水剂的表征与性能研究

Characterization and properties of polycarboxylate superplasticizer by mechanochemistry

采用机械化学法和水溶液聚合法合成一系列聚羧酸高性能减水剂(PCE),采用凝胶渗透色谱(GPC)和傅里叶变换红外光谱(FT-IR)对其进行结构表征,并对其固含量和水泥净浆流动度进行测试。结果表明:机械化学法与水溶液聚合法制备的PCE分子量主峰出峰范围和官能团特征吸收峰一致,说明两种方法合成的PCE具有相似的分子结构。机械化学法反应30 min单体转化率可达到50.52%;合成的PCE固含量均在90%以上,远高于水溶液聚合法的39.16%;在掺量为0.30%,水灰比为0.29时,净浆流动度可达到260 mm以上,具有良好的减水分散作用。

A series of polycarboxylate superplasticizers(PCEs)were synthesized by mechanochemistry and aqueous solution polymerization,and their structures were characterized by gel permeation chromatography(GPC)and Fourier transform infrared spectrometer(FT-IR).At the same time,its solid content and cement paste fluidity were tested.The results showed that the main peak range of PCE and the characteristic absorption peak of functional group prepared by mechanochemical method were consistent with the aqueous solution polymerization method,indicating that the PCEs synthesized by mechanochemical method and aqueous solution polymerization method has similar molecular structure.The monomer conversion rate reached 50.52% when the ball milling reaction was carried out for 30 min.The solid content of PCEs synthesized by mechanochemical method is above 90%,which is much higher than that of aqueous solution polymerization method(39.16%).When the dosage is 0.30% and the water-cement ratio is 0.29,the liquidity of the cement paste can reach260 mm or more,and it has good water-distributing dispersion.