Dou Guolan, Gao Lingling, Zhong Xiaoxing
Key Laboratory of Gas and Fire Control for Coal Mines (China University of Mining and Technology), Ministry of Education, Xuzhou 221116, China.
School of Safety Engineering, China University of Mining and Technology, Xuzhou 221116, China.
ACS Omega. 2024 Nov 12;9(47):47077-47087. doi: 10.1021/acsomega.4c07395. eCollection 2024 Nov 26.
In this study, melamine-urea-formaldehyde/nano-AlO (MUF/nano-AlO) composite gel foams were produced by foaming with CO generated by CaCO and phosphoric acid. Nano-AlO was introduced to the MUF matrix based on the optimum formulation obtained by the response surface methodology based on Box-Behnken design, and the effects of nano-AlO on the cell structure, apparent density, compressive strength, pulverization ratio, thermal stability, and thermal conductivity were investigated. The results revealed that the introduction of nano-AlO could improve the foaming and mechanical properties of MUF with smaller cell sizes, a narrower cell size distribution, decreased apparent density, higher compressive strength, and a decreased pulverization ratio. MUF/nano-AlO-1.5 with the most uniform cell size distribution had a 21% increased compressive strength, but its apparent density and pulverization ratio decreased by 10% and 13%, respectively. Although the char yield decreased with the introduction of nano-AlO, MUF/nano-AlO composite foams still presented improved thermal stability under 300 °C, with a thermal conductivity of 0.068 W/(m·K) and a limiting oxygen index of more than 30%. Therefore, MUF/nano-AlO composite gel foam could be employed in coal mines as thermal insulation sealing material due to its better cell structure and mechanical properties.
在本研究中，通过碳酸钙与磷酸反应产生的二氧化碳发泡制备了三聚氰胺 - 脲醛/纳米氧化铝（MUF/纳米Al₂O₃）复合凝胶泡沫材料。基于Box-Behnken设计的响应面方法获得的最佳配方，将纳米Al₂O₃引入到MUF基体中，并研究了纳米Al₂O₃对泡孔结构、表观密度、抗压强度、粉化率、热稳定性和热导率的影响。结果表明，纳米Al₂O₃的引入可以改善MUF的发泡性能和力学性能，使其泡孔尺寸更小、泡孔尺寸分布更窄、表观密度降低、抗压强度提高且粉化率降低。泡孔尺寸分布最均匀的MUF/纳米Al₂O₃-1.5的抗压强度提高了21%，但其表观密度和粉化率分别降低了10%和13%。虽然随着纳米Al₂O₃的引入焦炭产率降低，但MUF/纳米Al₂O₃复合泡沫在300℃以下仍表现出改善的热稳定性，热导率为0.068W/(m·K)，极限氧指数大于30%。因此，MUF/纳米Al₂O₃复合凝胶泡沫因其更好的泡孔结构和力学性能可作为煤矿隔热密封材料使用。
