【摘要】 为了改善MDF水泥的水敏性,以N—β—(氨乙基)—γ—氨丙基三甲氧基硅烷偶联剂对高铝水泥-聚乙烯醇基MDF水泥进行化学改性,测试了硅烷偶联剂改性MDF水泥的力学性能及耐水性,分析了改性MDF水泥的孔结构,并与未改性同种MDF水泥进行比较.结果表明:MDF水泥经硅烷偶联剂改性后,不仅抗弯、抗压强度、断裂韧性和微区硬度提高,孔隙减少,结构致密,而且表现出良好的耐水性,水浸泡90d的抗弯强度保持率由改性前的38%提高到改性后的80%,同时吸湿量和水的扩散系数下降.更多还原

【Abstract】 N-β-(aminoethyl)-γ-aminopropyl trimethoxy silane crosscoupling agent was used to improve the water sensitivity of high alumina cementpolyvinyl alcohol based macro defect free (MDF) material. The mechanical properties and water resistance of the MDF cement modified with the silane crosscoupling agent were tested and the pore structure was determined by mercury intrusion porosimeter. The results show that the bending strength, compressive strength, fracture toughness and micro zone hardness of the modified MDF cement are higher than those of the original ones. The modified MDF cement had a lower porosity and a more compact structure. It is more important that the modified MDF cement had a significant increase in water resistance in comparison with the original one. After 91 d of water immersion, the original MDF cement retained only 38% of its bending strength and the modified MDF cement retained up to 80%, and the moisture adsorption and diffusivity of water in the modified MDF cement was decreased as well.更多还原