SiO2气凝胶提高岩棉和玻璃棉性能的实验研究

Experimental study on improving the performance of rock wool and glass wool by silica aerogel

以无水乙醇为溶剂,SiO2气凝胶为溶质,制取SiO2气凝胶改性溶液。采用浸润及常压干燥的方法制备岩棉/SiO2气凝胶复合板和玻璃棉/SiO2气凝胶复合板,研究不同质量分数的SiO2气凝胶对复合板的短期吸水量、热导率及抗压强度的影响,并分析SiO2气凝胶质量分数为8%时制备的岩棉/SiO2气凝胶复合板和玻璃棉/SiO2气凝胶复合板的改性效果,进而采用扫描电镜对复合板的微观形貌进行了表征。结果表明,SiO2气凝胶均匀附着于无机纤维上,形成了较为稳定的复合体系;随着SiO2气凝胶质量分数的不断增加,岩棉/SiO2气凝胶复合板和玻璃棉/SiO2气凝胶复合板的短期吸水量和热导率都逐渐减小,其抗压强度有一定的提升。比较改性后的岩棉和玻璃棉,后者的防水性能和抗压强度改善更明显。当SiO2气凝胶质量分数达到8%时,岩棉/SiO2气凝胶复合板和玻璃棉/SiO2气凝胶复合板的短期吸水量较改性前分别下降了35.0%和36.2%,热导率分别下降了26.7%和18.3%,抗压强度分别提升了6.5%和102.9%。

Modified silica aerogel solution was prepared with anhydrous ethanol as solvent and silica aerogel as solute. The rock wool/SiO2 aerogel composite board and glass wool/SiO2 aerogel composite board were prepared by infiltration and prevailing pressure drying. Firstly, the effects of different mass percentages of silica aerogel on short-term water absorption, thermal conductivity and compression strength of the two kinds of composite boards were studied. Secondly, the performance of the prepared composite boards was analyzed when the mass percentages of SiO2 aerogel was 8%. Finally, the microstructure of the composite boards was characterized by scanning electron microscopy. The results showed that SiO2 aerogel was uniformly attached to the inorganic fibers to form a relatively stable composite system. With the increase of the mass fraction of SiO2 aerogel, the short-term water absorption and thermal conductivity of the composite boards were gradually reduced, and the compression strength was increased. Compared with the modified rock wool, the modified glass wool had better waterproof performance and better compression strength. When the mass fraction of SiO2 aerogel reached 8%, the short-term water absorption, the thermal conductivity and the compression strength of the rock wool/SiO2 aerogel composite board and the glass wool/SiO2 aerogel composite board decreased by 35.0% and 36.2%,26.67% and 18.3% and increased by 6.5% and 102.9% respectively, in comparison with those of the original materials.