硅酸钠模数对无机聚合物力学性能与微观结构的影响

摘要

用模数m=1.0、1.2、1.4和1.6的4种硅酸钠溶液作激发剂制备偏高岭土基无机聚合物,通过强度测试、红外分析 (IR)、X线衍射 (XRD)和扫描电镜 (SEM)等方法考察激发剂模数对无机聚合物力学性能和微观结构的影响.结果表明:模数在1.0~1.6变化时,激发剂中硅氧四面体呈低聚合态;随养护时间延长,无机聚合物抗压强度和抗折强度提高,m=1.2的无机聚合物28d抗压强度最高(74.6MPa),抗折强度为11.2MPa;4种无机聚合物主体相均呈非晶态,结构上由凝胶体和残留原料颗粒组成,其中,m=1.2时无机聚合物的显微结构最平整.%Four sodium silicate solutions of modulus rn = 1.0, 1.2, 1.4 and 1.6 were prepared as activators used in metakaolin-based geopolymer synthesis. The effects of modulus of activator on the mechanical properties and microstructure of the geopolymers were studied by strength test, infrared analysis ( IR ),X-ray diffraction (XRD), and scanning electron microscopy (SEM). Results showed that the most Si04tetrahedrals were in low poly-degree status when the modulus varied from 1.0 to 1.6. Compressive strength and flexural strength increased with the curing time. The geopolymer of m = 1.2 achieved the highest compressive strength at 28 d (74. 6 MPa) and its flexural strength was 11.2 MPa. The mineral composition of 4 geopolymers was similarly amorphous, and composed of geopolymeric gels and residual raw particles, while the microstructure of the geopolymer of m = 1.2 was the smoothest one.