阴离子型聚丙烯酰胺改性磷酸钾镁水泥的韧性及微观结构

Toughness and microstructure of anionic polyacrylamide modified potassium magnesium phosphate cement

为研究阴离子型聚丙烯酰胺对磷酸钾镁水泥韧性的改善情况,以阴离子型聚丙烯酰胺改性磷酸钾镁水泥为研究对象,结合孔结构分析、扫描电子显微镜、X射线衍射等微观试验,研究不同掺量阴离子型聚丙烯酰胺对磷酸钾镁水泥的凝结时间、抗压强度、抗折强度、弯曲韧度因子、冲击能量等性能的影响。试验结果表明:掺入适量的阴离子型聚丙烯酰胺能改善改性磷酸钾镁水泥的韧性,当阴离子型聚丙烯酰胺掺量低于2.0%时,弯曲韧度因子随阴离子型聚丙烯酰胺掺量的增加而增大;掺入阴离子型聚丙烯酰胺后不会改变磷酸钾镁水泥的水化产物类型,但水化产物形貌和内部结构发生变化,阴离子型聚丙烯酰胺形成胶体穿插在结构内部,从而提高了磷酸钾镁水泥的韧性。综上,当阴离子型聚丙烯酰胺掺量为2.0%时,综合性能最优。

To study the improvement of anionic polyacrylamide(APAM)on the toughness of potassium magnesium phosphate cement,the anionic polyacrylamide-modified potassium magnesium phosphate cement was used as the research object,and the effect of different content of APAM on the setting time,compressive strength,flexural strength,flexural toughness factor and impact energy of potassium magnesium phosphate cement were studiedthrough pore structure analysis,scanning electron microscope,X-ray diffraction and other microscopic tests.The results demonstrated that the addition of appropriate amount of APAM improved the toughness of magnesium potassium phosphate cement.When the contentof anionic polyacrylamide was less than 2.0%,the flexural toughness factor increased with the increasedcontent of APAM.The addition of APAM did not change the type of hydration products in magnesium potassium phosphate cement,but the morphology and internal structure of the hydration products changed.The APAM formed a colloid intercalation within the structure,thus enhancing the toughness of potassium magnesium phosphate cement.In conclusion,the optimal comprehensive performance was achieved when the APAM content was 2.0%.