聚合物改性水泥砂浆力学性能研究

摘要

为提高水泥砂浆的力学性能,以水作溶剂,过硫酸钾(KPS)作引发剂,将单体烯丙基磺酸钠(SAS)和甲基丙烯酸丁酯(BMA)接枝到母体羧甲基纤维素钠(CMC)上,通过乳液接枝共聚反应合成了聚合物乳液——羧甲基纤维素钠接枝共聚烯丙基磺酸钠-甲基丙烯酸丁酯(CMC-g-PSAS-PBMA).将加入聚合物乳液的水泥砂浆试样进行SEM表征,同时测其抗压与抗折强度,将从乳液中提取出来的聚合物粉末分别进行FTIR、SEM、XRD及TG表征.结果表明:当m(反应水量)/m(CMC)=29,m(SAS+ BMA)/m(CMC)=9,m(SAS)/m(BMA)=3,m(引发剂)/m(SAS+ BMA) =2％时合成的聚合物,控制减水率为15％,CMC-g-PSAS/PBMA掺量为1.5％,水泥砂浆的力学性能得以显著提高.%In order to improve the mechanical properties of cement mortars,with water as solvent,the synthesis of sodium carboxymethlcellulose-g-poly (sodium allysulfonate)-poly (butyl methacrylate) emulsion is carried out by potassium persulfate induced graft copolymerization and on carboxymethlcellulose graft,and the copolymerization emulsion is happened.Mechanical properties of cement mortars modified graft copolymer is characterized by scanning electron microscope and tested the compressive shrength and flexural shrength.The pure graft copolymer is extracted from the emuliosn for characterization,which is used fourier transform infrared spectre,scanning electron microscope,X-ray diffraction and thermal gravity analysis.The results show that,under water reduction efficiency of 15％,1.5％ doping content of CMC-g-PSAS-PBMA can effectively improve the mechanical properties of cement mortars.Meanwhile when the quality ration of water and CMC is 29,the ration of total monomers(SAS + BMA) is 9,the ration of SAS and BMA is 3 and add 2％ of the monomer initiator.