中文摘要：

本工作利用热重（TG）、气相色谱-质谱（GC/MS）以及在线光电离质谱法对聚氨酯硬泡（RPUF）和添加了阻燃剂聚磷酸铵（APP）与可膨胀石墨（EG）的RPUF的热解过程进行了研究。热重分析结果显示,3种材料的热降解过程均可分为两个阶段。GC/MS对3种材料热解产物的检测结果表明,APP的加入促使大量含氮多环芳烃生成,这些多环芳烃加速了高温下RPUF表面焦炭层的形成,有助于提高阻燃效果;而EG对于RPUF热解产物没有明显影响,说明EG是一种典型的物理膨胀型阻燃剂。在线光电离质谱的实验结果进一步验证了上述结论,并得出RPUF、RPUF/APP、RPUF/EG热解过程的两个阶段分别来自聚氨酯的初始热分解以及初始热解产物的二次分解。

英文摘要：

Rigid polyurethane foam（RPUF）exhibits wide applications in building engineering and thermal insulation,as well as furniture components due to its excellent mechanical and insulation properties.However,RPUF is highly flammable,combustion of which can cause serious economic loss and release smoke that is extremely harmful to the environment.Therefore,it＇s of great importance to improve the flame retardancy of RPUF.The use of intumescent flame retardants is one of the most economical and efficient ways to protect polymeric materials against fire.In this work,ammonium polyphosphate（APP）and expandable graphite（EG）were added to RPUF as flame retardants.Pyrolysis processes of pure RPUF and these two flame retarded RPUFswere investigated using thermogravimetry（TG）,gas chromatography-mass spectrometry（GC/MS）and on-line photoionization mass spectrometry（PIMS）.TG analysis shows that all the samples decompose in two major steps and more high-temperature residues are formed with the addition of APP and EG.On the basis of GC/MS analysis,the secondary pyrolysis products of PU are remarkably changed by APP.Large quantities of nitrogen-containing PAHs were found in the pyrolyzates of RPUF/APP,which could subsequently form the char layer to increase the flame retardancy of PU.However,the flame retardancy of EG mainly depends on its physical expansion character.Moreover,extremely similar pyrolyzates are exhibited for pure RPUF and RPUF/EG,which reveals that EG is typically aphysical expanding retardant.By virtue of the online detection and soft ionization characteristics,PIMS was used to further confirm the above experimental results.Two stages of the pyrolysis process could be assigned respectively to the primary decomposition of RPUF and to secondary reactions of primary products.However,PIMS with rare gas discharge lamp as ionization source has some inevitable drawbacks,such as fixed wavelength,low photon flux and large emittance.Recently,synchrotron vacuum ultraviolet（SVUV）light has proved to be a