镁渣地聚物复合改性聚氨酯注浆材料的制备及力学性能的研究

Preparation and Mechanical Properties Study of Magnesium Slag-Based Geopolymer Composite Modified Polyurethane Grouting Material

摘要: 为实现聚氨酯注浆材料的低成本化与性能优化，并推动镁渣、粉煤灰等工业固废的资源化利用，本研究制备了一种镁渣地质聚合物/聚氨酯复合注浆材料。以优化后的聚氨酯体系为基础，通过“一步法”将水玻璃激发的镁渣/粉煤灰地聚物引入其中，系统探究了水玻璃模数与固废掺量对材料力学性能的影响。结果表明：采用低模数水玻璃(n ≈ 1.52)且控制镁渣掺量为70%时，复合材料抗压强度最高，达3.96 MPa；但其粘结强度随固废掺量增加而下降。机理分析表明，水玻璃在体系中兼具激发剂与改性剂作用，其与聚氨酯间形成的Si-O-Si化学键合与地聚物凝胶的物理填充共同构建了稳定的有机无机互穿结构，是实现材料性能增强的关键。本研究为工业固废的高值化利用与道路修复材料的绿色升级提供了新途径。

Abstract: To reduce cost and optimize performance in polyurethane (PU) grouting while advancing the resource utilization of industrial solid wastes such as magnesium slag and fly ash, this study developed a magnesium‑slag-based geopolymer/PU composite grouting material. Building on an optimized PU system, a sodium‑silicate‑activated magnesium‑slag/fly‑ash geopolymer was incorporated via a one‑pot route. This study systematically investigated the effects of sodium‑silicate modulus and solid‑waste content on composite mechanical properties. The composite achieved a maximum compressive strength of 3.96 MPa when a low‑modulus sodium silicate (n ≈ 1.52) was used with 70% magnesium slag; however, bond strength decreased with increasing solid‑waste content. Mechanistic analysis indicates that sodium silicate plays a dual role as an activator and a modifier. Formation of chemical Si-O-Si linkages with PU, together with the physical filling effect of geopolymer gels, yields a stable organic-inorganic interpenetrating structure that underpins the observed performance enhancement. This work provides a pathway for high‑value utilization of industrial solid waste and the green upgrading of road‑repair materials.