Effect of curing temperature and SiO2/K2O molar ratio on the performance of metakaolin-based geopolymers
Effect of curing temperature and SiO2/K2O molar ratio on the performance of metakaolin-based geopolymers
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固化温度和SiO2/K2O摩尔比对偏高岭土基地质聚合物性能的影响
DOI：
10.1016/j.ceramint.2016.07.139
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发表时间：
2016
影响因子：
5.2
通讯作者：
Zhou Yu
中科院分区：
文献类型：
--
作者：
Yuan Jingkun;He Peigang;Jia Dechang;Yang Chao;Zhang Yao;Yan Shu;Yang Zhihua;Duan Xiaoming;Wang Shengjin;Zhou Yu
研究了固化温度和SiO2/K2O摩尔比对偏高岭土聚合物力学性能的影响。采用不同的固化温度（50°~ 90°C）进行固化。制备了一系列不同SiO2/K2O摩尔比(N)的地聚合物，N分别为2.4、2.0、1.6和1.2。研究了所得地聚合物的相组成、微观结构和力学性能。结果表明，固化温度和SiO2/K2O摩尔比影响了土聚合物的微观结构和力学性能。随着固化温度的升高，其微观结构变得更加致密，这有利于地聚合物力学性能的改善。最佳养护温度为≈80℃，抗压强度为106.2 MPa，弹性模量为8.3 GPa，力学性能最佳。随着SiO2/K2O摩尔比的增加，其微观结构多孔且含有未反应的偏高岭土颗粒，其力学性能急剧下降，这是由于高碱含量导致地聚合度低所致。
In this study, the effect of curing temperature and SiO2/K2O molar ratio on the mechanical properties of metakaolin-based geopolymers were investigated. Different curing temperatures (from 50° to 90 °C) were used for curing process. A series of geopolymers with different SiO2/K2O molar ratio (N) were prepared, withN=2.4, 2.0, 1.6 and 1.2, respectively. The phase composition, microstructure and mechanical properties of the resulting geopolymers were studied. The results indicate that curing temperature and SiO2/K2O molar ratio impacts final microstructures and mechanical properties of the resulting geopolymers. Microstructures become denser with increases in curing temperature, which was beneficial to the improvement of geopolymer's mechanical properties. The optimum curing temperature was ≈ 80 °C giving the best mechanical properties with the compressive strength of 106.2 MPa and elastic modulus of 8.3 GPa, respectively. With increasing SiO2/K2O molar ratios, the microstructure was quite porous and contained unreacted metakaolin particles, and the corresponding mechanical properties declined sharply, attributed to low degrees of geopolymerization caused by high alkali content.