## 1 Introduction
### Thermal Degradation and Remediation for Solid Waste  
The rising concern over perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) has led to models being developed to understand how PFOA, PFOS, and similar compounds undergo thermal and environmental degradation [32]. Various studies have also been performed to assess the combustion of fluoropolymers and their potential to degrade in the environment to various, smaller PFAS compounds that are considered persistent organic pollutants (POPs) [6; 33; 34; 35; 36; 37; 38; 39; 40]. While PFOS and PFOA are non-polymers and were previously used in AFFF, fluoropolymers  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Class** & **Molecular Structure** & & **Sources** & **References** \\ \hline \hline \multirow{4}{*}{\ \begin{tabular}{c} Chlorinated polyfluorinated ether sulfonate (FSA-B) \\ \end{tabular}  } & \multirow{4}{*}{ \begin{tabular}{c} Fire Fighting Foams \\ Chrome Plating Waste \\ \end{tabular}  } & \multirow{4}{*}{[12; 16]} \\  & &  
also have an important use in the plastics and coatings industry. Specifically, PFAS polymers are used as binders in plastic/polymer bonded explosives (PBX) and in munition components such as gaskets, wiring sheaths, tubing, and seals, with the most prevalent materials being PTFE, vinylidene difluoride/hexafluoropropylene copolymer (Viton A, and Viton B), and polychlorotrifluoroethylene (Kel-F 800). Several studies have looked at the thermal decomposition behavior of PBX, utilizing various instruments to measure elastic and mechanical properties in order to better understand the long-term, high-temperature stability, and compatibility of the explosive mixture of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX)/1,3,5-triamino-2,4,6-trinitrobenzene (TATB), and Viton A [41; 42; 43]. As shown in Table 1, PTFE has a -CF\({}_{2}\)- backbone and is terminated on both ends of the polymer with -CF\({}_{3}\). [6] Viton A, Viton B, and Kel-F 800 have a similar structure to PTFE; however, they exhibit slight differences such as that Kel-F 800 also includes chlorine atoms in its structure. There are currently several methods used to destroy various PFAS waste such as end-of-life fluoropolymers in various materials and include, but are not limited to, incineration, pyrolysis, and smoldering, also referred to as smoldering combustion. Incineration is a high-temperature flaming process that typically occurs in an open air space, while smoldering is a flameless combustion process that occurs on the surface of a condensed fuel [1]. While both methods can be used to treat fluorinated waste, smoldering is a self-sustaining and is, therefore, more energy efficient compared to incineration. Pyrolysis is similar to incineration in that it is a high-temperature process used for thermal decomposition, except it occurs in an inert atmosphere [44]. Critical to the effectiveness of this processes is achieving a temperature greater than 900 \({}^{\circ}\)C [1]. The goal of these methods pertaining to PFAS waste is to ensure that these fluoropolymers are exposed to a sufficient and sustainable temperature that ensures successful destruction of toxic PFAS compounds, as the fluoropolymers thermally degrade while still being efficient and safe. Several studies have tested the efficacy of these methods to determine if they reach temperatures high enough for a sufficient duration to allow for complete degradation [45; 46]. Alternative methods to incineration such as mineralization of fluorinated compounds during thermal treatment, or a plasma based water treatment, are also being investigated as they may be safer and more efficient to treat waste [1; 47; 48]. Recently, there are concerns amongst communities regarding side effects from exposure at impacted locations where thermal degradation of PFAS compounds from disposal of munitions using various methods such as open burning (OB), open detonation (OD), and incineration.