Ramgobin Aditya, Fontaine Gaëlle, Bourbigot Serge
CNRS, INRAE, Centrale Lille, UMR 8207-UMET-Unité Matériaux et Transformations, Univ. Lille, F-59000 Lille, France.
Polymers (Basel). 2020 Aug 10;12(8):1789. doi: 10.3390/polym12081789.
The thermal and fire behaviors of a high-performance polymeric material-polyether ether ketone (PEEK) was investigated. The TG plots of PEEK under different oxygen concentrations revealed that the initial step of thermal decomposition does not greatly depend on the oxygen level. However, oxygen concentration plays a major role in the subsequent decomposition steps. In order to understand the thermal decomposition mechanism of PEEK several methods were employed, i.e., pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), thermogravimetric analysis (TGA) coupled with a Fourier-transform infrared spectrometer (FTIR). It was observed that the initial decomposition step of the material may lead to the release of noncombustible gases and the formation of a highly crosslinked graphite-like carbonaceous structure. Moreover, during the mass loss cone calorimetry test, PEEK has shown excellent charring and fire resistance when it is subjected to an incident heat flux of 50 kW/m². Based on the fire behavior and the identification of pyrolysis gases evolved during the decomposition of PEEK, the enhanced fire resistance of PEEK was assigned to the dilution of the flammable decomposition gases as well as the formation of a protective graphite-like charred structure during its decomposition. Moreover, at 60 kW/m², ignition occurred more quickly. This is because a higher rate of release of decomposition products is achieved at such a heat flux, causing a higher concentration of combustibles, thus an earlier ignition. However, the peak of heat release rate of the material did not exceed 125 kW/m².
对一种高性能聚合物材料——聚醚醚酮（PEEK）的热行为和燃烧行为进行了研究。不同氧气浓度下PEEK的热重曲线表明，热分解的初始步骤对氧气水平的依赖性不大。然而，氧气浓度在随后的分解步骤中起主要作用。为了理解PEEK的热分解机理，采用了几种方法，即热解-气相色谱-质谱联用（Py-GC-MS）、热重分析（TGA）与傅里叶变换红外光谱仪（FTIR）联用。观察到该材料的初始分解步骤可能导致不可燃气体的释放以及形成高度交联的类石墨碳质结构。此外，在质量损失锥形量热试验中，当PEEK受到50 kW/m²的入射热通量时，表现出优异的成炭和耐火性能。基于PEEK的燃烧行为以及对其分解过程中产生的热解气体的鉴定，PEEK增强的耐火性归因于可燃分解气体的稀释以及在其分解过程中形成保护性的类石墨炭化结构。此外，在60 kW/m²时，点火更快发生。这是因为在这样的热通量下实现了更高的分解产物释放速率，导致可燃物浓度更高，从而更早点火。然而，该材料的热释放速率峰值未超过125 kW/m²。
