丙烯酰胺原位聚合与纳米二氧化硅协同改性水泥基封孔材料OA

To enhance the compactness and toughness of cement-based borehole sealing materials used in gas extraction,a synergistic modification of cement mortar was achieved through the in-situ polymerization of nano-silica(NS)and acrylamide(AM).A comprehensive investigation into the enhancement mechanism was conducted via mechanical performance tests and microstructural analyses,including X-ray diffraction(XRD),thermogravimetry(TG)and scanning electron microscopy(SEM).The results indicate that NS pri-marily exerts nucleation and filling effects,effectively promoting early-age hydration and refining the pore structure,whereas AM forms a polymer network within the cement matrix,contributing to long-term tough-ness.With the combined addition of 1.5 wt%NS and 6 wt%AM,the 28-day compressive and flexural strengths increased to 37.26 MPa and 14.43 MPa,respectively,while the compressive-to-flexural strength ratio decreased from 4.1(control group)to 2.5.This combination resulted in an optimal balance between overall strength and toughness.Microstructural analysis revealed that the synergistic interaction between NS and AM accelerates the formation of early hydration products and improves pore morphology,endowing the sealing material with enhanced mechanical stability and deformation adaptability.The findings provide an ef-fective strategy for designing high-performance borehole sealing materials.