【作者】 刘辉；

【导师】 王飞跃； 施方桂；

【作者基本信息】 中南大学 ， 工程（专业学位）， 2022， 硕士

【摘要】 钨尾矿是钨矿在选矿过程中产生的固体废弃物,对其的综合利用一直是学术研究的热点问题。本论文为了实现钨尾矿的高效资源化利用,采用表面改性、包覆以及共沉淀法制备钨尾矿基填料,应用于膨胀型阻燃材料领域。通过防火性能、热重分析、生烟性能测试、锥形量热仪、加速老化试验、炭层演化、傅里叶红外光谱等方法考察钨尾矿基填料对膨胀型防火涂料阻燃、抑烟、成炭和抗老化性能的影响,揭示了钨尾矿基填料在膨胀型防火涂料中的阻燃、催化成炭和抗老化机制。本论文开展的主要研究内容和成果如下:(1)通过洗涤、粉碎和表面改性工艺获得硅烷改性钨尾矿填料(KH-TTF),并应用于膨胀型防火涂料。研究结果表明,当KHTTF的质量分数为3%时,协效阻燃和抑烟作用最佳,涂层的火焰传播比值为4.3,900 s时背面平衡温度为84.8℃,烟密度等级为14.2%。KH-TTF填料的加入能促进涂层在燃烧过程中形成更多的热稳定性交联结构和芳香结构,以促进形成更加致密和稳定的膨胀炭层结构,以阻隔热量和物质的传递,达到较好的协效阻燃和抑烟作用。(2)采用吡咯原位聚合反应制备聚吡咯钨尾矿填料(PPYTTF),并与膨胀阻燃剂(IFR)复配制备膨胀型防火涂料。结果表明,PPY-TTF的合成有效地解决了钨尾矿在涂层中分散不均匀的问题,为改善膨胀型防火涂料的防火和抗老化性能提供理论基础。而PPY-TTF在涂层中的协同效应取决于其含量,含有3wt%PPY-TTF填料的膨胀型防火涂料在测试样品中表现出最优的协效防火和抗老化效能。相比于未改性钨尾矿填料,添加3wt%PPY-TTF涂层的质量损失减少了10.7%,火焰传播比值减少了35.4%,表明PPY-TTF具有更优异的协效阻燃作用和催化成炭能力。(3)通过共沉淀法制备钨尾矿基水滑石填料(TTF-LDH),将其引入膨胀型防火涂料以增强其阻燃、抑烟、催化成炭和抗老化性能。研究结果表明:TTF-LDH的加入能促进涂层形成坚硬而致密的炭层,以阻隔炭层和火源之间可燃物和热量的传递,进而有效提高膨胀型防火涂料的热稳定性和催化成炭能力。加速老化实验表明,TTF-LDH可以提供更好的片层阻隔效果,增强涂层的结构稳定性,减少阻燃剂的迁移、分解和涂层的起泡、粉化现象,从而赋予涂层更好的结构完整性和防火耐久性。图49幅,表19个,参考文献112篇更多还原

【Abstract】 Tungsten tailing is a solid waste produced from tungsten ore during the beneficiation process and its comprehensive utilization has been a hot issue in academic research.In this thesis,surface modification,decorated and coprecipitation methods were utilized to prepare tungsten tailing-based fillers for intumescent fire-retardant material field.The effects of fire resistance,smoke suppression,char formation and antiageing properties of tungsten tailing-based fillers in intumescent fireretardant coatings were investigated by fire protection,cone calorimeter analysis,thermogravimetric analysis,smoke density test,accelerated ageing test,char layer evolution and Fourier infrared spectroscopy,thus revealing the fire resistance,char formation and anti-ageing mechanisms of tungsten tailing-based fillers.The main research contents and results carried out in this thesis are as follows.(1)Tungsten tailing filler(KH-TTF)was obtained by washing,pulverizing and surface modification of tungsten tailing and applied to intumescent fire-retardant coatings.The results show when the mass fraction of KH-TTF is 3 %,the coating shows the best synergistic effects on fire retardancy and smoke suppression among the samples,which exhibits the flame spread rate of 4.3,the equilibrium backside temperature of 84.8 °C at 900 s,and the smoke density rating value of 14.2 %.Char residue analysis indicates that the incorporation of KH-TTF can promote the coating to form more cross-linking structures and aromatic structures during burning,thus producing a more dense and thermally stable intumescent char layer against heat and mass transfer,which achieves better synergistic fire retardancy and smoke suppression effects.(2)Polypyrrole-decorated tungsten tailing particles(PPY-TTF)were prepared via in situ polymerization of pyrrole in the presence of tungsten tailing particles(TTF),and compounded with intumescent flame retardant(IFR)to prepare an intumescent fire-resistant coating.The results suggest that the synthesis of PPY-TTF effectively solves the poor dispersion of tungsten tailing in the coating,which provides the theoretical foundation to improve the fire resistance and anti-ageing performance of the intumescent fire-retardant coatings.While the synergistic effect of PPYTTF in the coating depends on its content,the intumescent fire-resistant coating containing 3wt % PPY-TTF exhibits the optimal synergistic fire resistance and anti-ageing properties in the tested samples.Compared with the unmodified tungsten tailing filler,the coating containing 3wt % PPYTTF has a 10.7 % reduction in mass loss and 35.4 % reduction in flamespread rating,indicating that the presence of PPY-TTF has a better synergistic effect on improving the fire resistance and char formation of intumescent fire-retardant coatings.(3)Tungsten tailing-based hydrotalcite filler(TTF-LDH)was synthesized by coprecipitation method and then introduced into intumescent fire-retardant coatings to enhance the fire-retardant,smoke suppression and anti-ageing properties of coatings.The results reveal that the addition of TTF-LDH promotes the formation of a hard and dense char layer from the coating,blocking the transfer of combustible materials and heat between the char layer and fire,thus effectively improving the thermal stability and char-forming properties of the intumescent fire-retardant coatings.In the accelerated ageing test,TTF-LDH can provide better barrier effect of the lamellae,enhance the structural stability of the coating,and reduce the migration and decomposition of flame retardant and the blistering and chalking of the coating,thus giving the coating better structural integrity and durability of fire resistance.There are 49 figures,19 tables and 112 references in the thesis.更多还原