激发剂浓度对偏高岭土基地聚物性能的影响机制

研究了激发剂、固化温度等外部因素对地聚物力学性能的影响及其机制，以NaOH和Na₂SiO₃作为激发剂，通过正交试验考察了偏高岭土基地聚物的力学性能对激发剂模数、激发剂浓度、固化温度和固化时间等影响因素的敏感性。通过微量热、红外光谱和扫描电镜-能谱方法分析了激发剂浓度影响聚合反应过程及地聚物性能的作用机理。试验结果表明:激发剂浓度是影响地聚物力学性能的最关键因素，地聚物抗压强度随激发剂浓度增加而提高；次关键因素是激发剂模数，地聚物强度随激发剂模数增大而降低。随着激发剂浓度增大，聚合反应逐渐充分，地聚物力学性能也随之提高；激发剂浓度为80%时聚合反应趋向完全，地聚物强度提高到99.98 MPa，生成物Si/Al大于1。 

Mechanism of activator concentration influencing properties of metakaolin-based geopolymer

We studied the influence and mechanism of external factors including activator and curing temperature on the mechanical properties of geopoylmer. NaOH and Na₂SiO₃ were used as the activator. And the sensitivity of the mechanical properties of metakaolin-based geopolymer to the activator modulus, the activator concentration, the curing temperature, and the curing time was analyzed by orthogonal tests. The mechanism of the activator concentration influencing geopolymerization and synthetics properties was investigated by the microcalorimetric, infrared spectrum and scanning electron microscope-energy disperse spectroscopy. The test results show that the concentration of activator is the most important factor for mechanical properties of geopolymer. The compressive strength of geopolymer increases with the increase of the activator concentration. The activator modulus ranks second, the increase in which results in the decrease of the geopolymer strength. Higher degree of polymerization is obtained when the concentration of activator increases. The polymerization reaction tends to full completion and mechanical properties of geopolymer increase subsequently, the strength of geopolymer increases to 99.98 MPa when the activator concentration reaches 80%, moreover the ratio of silicon to aluminium is greater than 1.