硅橡胶泡沫（SiFs）结合了硅橡胶和泡沫材料的特点，一方面具有优良的隔热性、稳定性、高柔软性、高弹性等，已广泛应用于航空航天、汽车等领域；另一方面其侧链的碳氢基团和泡孔的存在导致SiFs比表面积增大，使其容易燃烧且会产生大量烟气，严重威胁人员安全。蒙脱土（MMT）作为优异的成炭剂，来源广泛、价格低廉，已被应用到多种聚合物泡沫的阻燃研究中。但MMT遇水容易团聚，可能会破坏泡沫材料的结构，进而影响材料性能。本文通过探索MMT的改性方法、筛选不同的协效阻燃剂，制备出阻燃效果优良的SiFs复合材料，并研究了SiFs复合材料的阻燃抑烟性能。主要研究内容如下：

（1）分别以十六烷基三甲基溴化铵（CTAB）、四丁基溴化铵（TBAB）、十二烷基硫酸钠（SDS）、十二烷基苯磺酸钠（SDBS）为改性剂，对钠基MMT进行有机改性，制备了四种不同类型的改性MMT，并通过FTIR、XRD、激光粒度仪表征改性MMT的结构特征。结果表明：改性后各类改性MMT的衍射峰均向小角方向移动，表明层间距扩大；2800~3000 cm^-1处均出现了C-H基团的对称和反对称的伸缩振动峰，说明改性MMT被成功制备。

（2）采用氧指数测试仪、垂直燃烧测试仪、锥形量热仪、橡胶拉伸仪分别测试了含四种改性MMT的SiFs复合材料的阻燃抑烟性能和力学性能。结果表明：含CTAB改性MMT（CMMT）的SiFs复合材料阻燃抑烟性能最优，其热释放峰值（PHRR）、产烟率峰值（PSPR）、总产烟量（TSP）及火灾蔓延指数均有明显下降。力学结果表明CMMT能有效改善MMT对SiFs复合材料的抗拉强度和抗压强度的影响，显著提升SiFs复合材料的抗撕裂强度。

（3）在优选出CMMT为最优阻燃剂配方的基础上，制备出含CMMT/氢氧化铝（ATH）、CMMT/硼酸锌（ZB）、CMMT/三氧化二锑（Sb₂O₃）、CMMT/三氧化钼（MoO₃）四种协效阻燃体系的SiFs复合材料，并对比分析各类SiFs复合材料的阻燃抑烟效果。结果表明CMMT与ZB的协同阻燃效果最好，当CMMT与ZB配比为2:1时，复合材料的氧指数比SiFs原样高出11.3%，点燃时间（TTI）延长了26 s，PHRR、总热释放量（THR）、PSPR、TSP均有明显降低，火灾性能指数比SiFs原样提高了141.1%，且对CO和CO₂的产生也有一定的抑制效果。

（4）通过热重测试结合热动力学分析、热重红外联用及扫描电镜对SiFs原样、含CMMT的SiFs、含CMMT/ZB的SiFs三个样品的热分解行为、气相产物及炭层形貌分析，从凝聚相和气相两个方面揭示了CMMT/ZB对SiFs复合材料的阻燃机理。发现CMMT与ZB复配会使SiFs复合材料在燃烧后形成了硅酸盐和玻璃态B₂O₃的复合孔状炭层，有效地起到隔热、隔氧及吸烟作用；复合材料在高温下生成H₂O和CO₂等不燃性气体产物，显著降低了SiFs复合材料表面的可燃气体浓度，同时H₂O分子蒸发吸收了SiFs复合材料表面的热量，达到良好的阻燃作用。

Silicone rubber foam (SiFs) amalgamates the advantages of both silicone rubber and foam, exhibiting exceptional characteristics such as superior thermal insulation, stability, high elasticity, and flexibility. Consequently, it has found widespread applications in the aerospace, automotive, and other allied domains. In addition, the existence of hydrocarbon groups and bubble holes in the side chain causes the increase of specific surface area, which makes it easy to burn and produce a large amount of smoke, which seriously threatens the safety of personnel. Montmorillonite (MMT), as an excellent char-forming agent, has a wide range of sources and low price and has been applied to the flame retardancy research of various polymer foams. However, MMT is easy to agglomerate when it encounters water, which may damage the structure of foam materials and further affect the material properties. In this paper, In this paper, by exploring the modification method of MMT and screening different co-effecting flame retardants, SiFs composites with excellent flame retardancy were prepared, and the flame retardancy and smoke suppression performance of SiFs composites were studied. The main research contents are as follows:

In this study, four types of modified MMT were prepared by using hexadecyl trimethyl ammonium bromide (CTAB), tetrabutylammonium bromide (TBAB), sodium dodecyl sulfate (SDS), and sodium dodecylbenzene sulfonate (SDBS) as modifiers to modify sodium-based MMT. The structural characteristics of the modified MMT were characterized by Fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD), and laser particle size analyzer. The results showed that the diffraction peaks of four types of modified MMT shifted towards the small angle direction after modification, indicating an expansion of the interlayer distance. The FTIR spectra showed symmetric and antisymmetric stretching vibration peaks of C-H groups at 2800~3000 cm-1 , indicating the successful preparation of modified MMT.

The flame retardant and smoke suppression properties and mechanical properties of SiFs composite containing four kinds of modified MMT were tested by oxygen index tester, vertical combustion tester, cone calorimeter and rubber tension tester. The results showed that the SiFs composite containing CTAB modified MMT (CMMT) had the best flame retardant and smoke suppression performance, and its peak heat release (PHRR), peak smoke yield (PSPR), total smoke yield (TSP) and fire spread index decreased significantly. The mechanical results show that CMMT can effectively improve the influence of MMT on the tensile strength and compressive strength of SiFs composites, and significantly improve the tearing strength of SiFs composites.

After selecting the optimal formulation for CMMT, SiFs containing four synergistic flame retardant systems of CMMT/ATH, CMMT/ZB, CMMT/Sb2O3, CMMT/MoO3 were prepared, and their flame retardancy and smoke suppression effects were compared and analyzed. The results indicate that the synergistic flame retardant effect of CMMT and ZB is the best. When the ratio of CMMT to ZB is 2:1, the oxygen index of the composite material is 11.3% higher than that of pure SiFs, the time to ignition (TTI) is extended by 26 s, and PHRR, THR, PSPR, and TSP are all significantly reduced. The fire performance index (FPI) is increased by 141.1% compared to pure SiFs, and there is also some inhibition of the production of CO and CO2.

Through thermogravimetric test combined with thermodynamic analysis, thermogravimetric infrared coupling and SEM, the thermal decomposition behavior, gas phase products and carbon layer morphology analysis of original SiFs, CMMT-containing SiFs and CMMT/ZB-containing SiFs were analyzed. The flame retarding mechanism of CMMT/ZB/SiFs composite was revealed from two aspects of the condensed phase and gas phase. It was found that the compound of CMMT and ZB made the composite porous carbon layer of silicate and glassy B2O3 formed after the combustion of SiFs composite material, which effectively played the role of heat insulation, oxygen insulation and smoking; Additionally, the composite material generated non-flammable gases such as H2O and CO2 at high temperatures, significantly reducing the concentration of combustible gases on the surface of SiFs and absorbing the heat on the surface, thus achieving good flame retardancy.