低引气减缩型聚羧酸系减水剂合成及性能研究

Preparation and Properties of Low Air-entraining and Shrinkage-reducing Polycarboxylate Superplasticizer

混凝土最大的缺陷是收缩开裂问题。以酯化大单体丁氧基聚乙二醇甲基丙烯酸酯(BPEGMA)、甲基丙烯酸(MAA)、减缩功能单体一缩二丙二醇单甲醚马来酸酯(DPGMAL)和消泡单体聚丙二醇丙烯酸酯(PPGA400)为原料合成了一种低引气减缩型聚羧酸系减水剂。考察了大单体种类、不同分子量BPEGMA、MAA、DPGMAL和PPGA400用量对产品性能的影响规律,确定了合成产品最佳的工艺条件为BPEGMA1000∶MAA∶DPGMAL∶PPGA400的摩尔比为1∶3.2∶0.6∶0.3。与市场上同类产品相比,合成产品具有较高的减水率、较好的减缩性能和较低的引气性。

The crack of concrete caused by shrinkage is a serious problem. A low air-entraining and shrinkage-reducing polycarboxylate superplasticizer was prepared by different type and molecular macromonomer BPEGMA,MAA,shrinkage-reducing monomer DPGMAL and de-foaming monomer PPGA400.The influences of the amount of all the materials were discussed. The optimal molar ratio of BPEGMA1000,MAA,DPGMAL and PPGA400 was 1∶ 3. 2∶ 0. 6∶ 0. 3. Compared with the like product in the market,the copolymer had the better water-reducing,shrinkage-reducing and lower air-entraining property.