Volatile Decomposition Products Research Articles

Liquid crystalline polyurethane/POSS hybrid nanocomposites pyrolysis studies by Py-GC/MS and TG/FTIR techniques

The process of pyrolysis of liquid crystalline polyurethane (LCPU) composites with polyhedral oligomeric silsesquioxanes (POSS) has been studied using pyrolysis - gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetry/Fourier transform infrared spectroscopy (TG/FTIR) coupled thermoanalytical techniques. LCPU elastomers modified with POSS molecules with different architectures, bearing aromatic, isobutyl and cycloaliphatic moieties, yield various volatile products of pyrolysis that were collected and characterized. The TG study showed significant differences in the thermal behavior of composites studied, evidencing the influence of the silsesquioxane type on the polyurethane pyrolysis paths. FTIR study of volatile products of thermal decomposition showed the presence of characteristic bands originated from carbonyl, amine, ether, methylene, and unsaturated hydrocarbon linkages. GC/MS investigation confirmed the existence of compounds identified by the IR method. The application of both thermoanalytical methods made it possible to postulate the thermal decomposition routes of PU/POSS hybrids and to point out the main factors responsible for changes in the thermal stability.

Development of Versatile, thermally stable, flexible, UV-resistant and antibacterial polyvinyl alcohol-Nanodiamonds composite for efficient food packaging

This research paper reports an enhancement of thermal, optical, mechanical and antibacterial activities of the Polyvinyl alcohol–Nanodiamonds (PVA-NDs) composite required for the food packaging industry. The synthesis of composites was done by the wet processing method. The large surface area of NDs facilitated the robust interaction between the hydroxyl group and macromolecular chains of PVA to enhance the hydrogen bonding of PVA with NDs rather than PVA molecules. Thus, a reduction in PVA diffraction peak intensity was reported. NDs improved the thermal stability by preventing the out-diffusion of volatile decomposition products of PVA. The results also revealed an enhancement in tensile strength (∼60 MPa) and ductility (∼180 %). PVA-NDs composite efficiently blocked the UVC (100 %), most of the part of the UVB (∼85 % above 300 nm), and UVA (∼58 %). Furthermore, enhanced antibacterial activities were reported for PVA-NDs composite against E. coli and S. aureus. NDs accumulated around the bacterial cells prevented essential cellular functions and led to death. Hence, this composite could be a promising candidate for safe, thermally stable, strong, flexible, transparent, UV- resistant antibacterial food packaging material.

Pyrolysis of plasticized films based on soy protein, denatured by different substances

Polymer films based on soy protein isolate (SPI) were obtained using the thermo-pressing method. Plasticizers and denaturing agents were added to ensure better the film-forming properties and reduce the fragility of the resulting materials. Glycerol, sorbitol and their mixture were used for plasticization, while solutions of alkali (potassium hydroxide), surfactants of natural origin (sodium coco sulfate) and reducing agent (sodium sulfite) were used for denaturation. By combining different types of plasticization and denaturation, a series of samples were obtained and compared with a sample based on raw soy protein. In addition to the obvious differences in the appearance of the films, the processes of their thermal degradation, studied by pyrolysis mass spectrometry, also differed significantly. In fact, unprocessed soy protein has the highest thermal stability with the temperature of the most intensive decomposition equal to 270 °С, which can decrease to 200 °С under the conditions of denaturation and plasticization. Despite the increase in the number of film components, the amount of volatile decomposition products decreases (from 86 to 32), as well as the molecular weight of the heaviest of them (from 169 to 74). This is a sign of a change in the mechanism of soy protein degradation due to denaturation and plasticization caused by transformations in its supramolecular structure, such as unfolding and extension of macrochains with increased availability of functional groups. The pyrolytic behavior of some protein samples plasticized with sorbitol is closest to that of untreated soy protein, which may indicate a lower plasticizing efficiency of sorbitol with longer molecules than glycerol. The interpretation of the recorded mass spectra of the volatile pyrolysis products showed that the thermal degradation of protein materials is dominated by processes such as decarboxylation, dehydration, deamination and decarbonylation, while in the presence of plasticizers the splitting of their own molecules also becomes dominant. The characteristic mass spectra of protein films denatured by surfactants also contain ionic fragments of relatively high molecular weight, probably derived from sodium coco sulfate molecules.

UV aging of styrene-acrylic polymer SiO2 and TiO2 composites

The photodegradation of coatings based on styrene-acrylic polymer and nanoparticles: hydrophobized silica (40–70 nm) and photoactive titanium dioxide (50–100 nm) was investigated. By the means of FTIR, goniometry, and SEM, it is shown that the use of titanium dioxide provides acceleration of photooxidation processes in comparison with the silica-based system. However, the formation of volatile decomposition products is not accelerated, which leads to the formation of a textured surface with polar polymer residues. Such surfaces have high wettability because of the capillary structure and intrinsic high surface energy. It was confirmed that the addition of nanoparticles reduces the ablation rate to 0.74 µm/h for TiO2 and to 0.85 µm/h for SiO2 due to the UV shielding effect.

Thermal Investigations of Annelated Triazinones-Potential Analgesic and Anticancer Agents.

In this article, for the first time, TG-DSC and TG-FTIR investigations of potential pharmaceutics, i.e., analgesic and anticancer active annelated triazinones (1-9) have been presented. The thermal behaviour of these molecules was established in oxidative and inert conditions. The solid-liquid phase transition for each compound (1-9) was documented by one sharp DSC peak confirming the high purity of each sample studied. All the molecules were characterised in terms of calorimetric changes and mass changes during their heating. They revealed high thermal stability in oxidative and inert conditions. The observed tendency in thermal stability changes in relation to a substituent present at the phenyl moiety was found to be similar in air and nitrogen. It was confirmed that annelated triazinones 1-9 were stable up to a temperature range of 241-296 °C in air, and their decomposition process proceeded in two stages under oxidative conditions. In addition, it was established that their thermal stability in air decreased in the following order of R at the phenyl moiety: 4-Cl > 3,4-Cl2 > H > 3-Cl > 4-CH3 > 2-CH3 > 3-CH3 > 2-Cl > 2-OCH3. The volatile decomposition products of the investigated molecules were proposed by comparing the FTIR spectra collected during their thermogravimetric analysis in nitrogen with the spectra from the database of reference compounds. None of annelated triazinones 1-9 underwent any polymorphic transformation during thermal studies. All the compounds proved to be safe for erythrocytes. In turn, molecules 3, 6, and 9 protected red blood cells from oxidative damage, and therefore may be helpful in the prevention of free radical-mediated diseases.

The Influence of Diisocyanate Structure on Thermal Stability of Thermoplastic Polyurethane Elastomers Based on Diphenylmethane-Derivative Chain Extender with Sulfur Atoms.

The work is a continuation of the research on thermoplastic polyurethane (TPU) elastomers containing sulfur atoms which are incorporated into the polyurethane chain using aliphatic-aromatic chain extenders. These materials show some improved properties in relation to conventional ones, e.g., adhesion to metals, bacterial resistance and refractive index. The present study deals with the detailed characteristics of the process of thermal decomposition of TPU elastomers obtained from 2,2'-[methylenebis(1,4-phenylenemethylenethio)]diethanol, 1,1'-methanediylbis(4-isocyanatobenzene) (MDI) or 1,6-diisocyanatohexane (HDI) and poly(oxytetramethylene) diol of Mn = 2000 g/mol by thermogravimetric analysis coupled on-line with Fourier transform infrared spectroscopy. The analysis was performed under inert and oxidative conditions. All TPU elastomers were found to have a relatively good thermal stability, with those based on aromatic diisocyanate being at an advantage. In helium, they are stable up to 280-282 °C (from HDI) and 299-301 °C (from MDI), whereas in synthetic air up to 252-265 °C (from HDI) and 261-272 °C (from MDI), as measured by the temperature of 1% mass loss. Depending on the content of the hard segments and the tested atmosphere, the TPU elastomers decompose from one to four stages. From the analysis of the volatile decomposition products, it follows that the decomposition of both types of hard segments was accompanied by the evolution of carbonyl sulfide, carbon dioxide, water, sulfide dioxide, alcohols and aromatic compounds. For the hard segment derived from HDI, isocyanates, amines, and unsaturated compounds were also identified, while for the MDI-derived one, aldehydes were discovered. In turn, the polyether soft segment decomposed mainly into aliphatic ethers, aldehydes, and carbon monoxide.

A novel green IFR system: Design of a self-assembled peanut shell-based flame retardant and its fire performance in EP

Carbon derived from peanut shell (CPS) with 2D structure has been proved to own sufficient thermal stability and is a promising flame retardant (FR) additive for EP in our previous work. To further explore the feasibility of implementing CPS into the intumescent fire retardant (IFR) system, a novel green IFR system was first proposed in this study. Environmental-friendly chemicals phytic acid (PA) and melamine were self-assembled on the carbon's surface through the hydrothermal method. Cone calorimeter test results reveal that 3 wt% loading of the proposed IFR reduces total heat release (THR) by 38.8 % and total smoke release (TSR) by 31.3 %. What's more, the char residue grows significantly, from 5.8 % to 14.3 %. The fire retardancy mechanism was also studied. For the gaseous phase, the release of inert gas products from melamine prevents volatile decomposition products into the combustion zone. In terms of the solid phase, a synergistic barrier effect is provided by 2D structure of peanut shell derived carbon and the intumescent residue with a compact exterior layer, protecting the underlying polymer matrix. This green IFR system provides better fire performance, which can be a potential alternative for EP and extend its application.

Origin of Decomposition in a Family of Molybdenum Precursor Compounds.

The bis(tert-butylimido)-molybdenum(VI) framework has been used successfully in the design of vapor-phase precursors for molybdenum-containing thin films, so understanding its thermal behavior is important for such applications. Here, we report the thermal decomposition mechanism for a series of volatile bis(alkylimido)-dichloromolybdenum(VI) adducts with neutral N,N'-chelating ligands, to probe the stability and decomposition pathways for these molecules. The alkyl groups explored were tert-butyl, tert-pentyl, 1-adamantyl, and a cyclic imido (from 2,5-dimethylhexane-2,5-diamine). We also report the synthesis of the new tert-octyl imido adducts, (tOctN)2MoCl2·L (L = N,N,N',N'-tetramethylethylenediamine or 2,2'-bipyridine), which have been fully characterized by spectroscopic techniques as well as single-crystal X-ray diffraction and thermal analysis. We found that the decomposition of all compounds follows the same general pathway, proceeding first by the dissociation of the chelating ligand to give the coordinatively unsaturated species (RN)2MoCl2. Subsequent dimerization results in either an imido bridged adduct, [(RN)Mo(μ-NR)Cl2]2, or a chloride bridged adduct, [(RN)2Mo(μ-Cl)Cl]2, depending on the size of the R group. The dimeric species then likely undergoes an intramolecular γ-hydrogen transfer to yield a nitrido-amido adduct, (RHN)MoNCl2, and an alkene. Ultimately, the resulting molybdenum species appears to decompose into free tert-alkylamine and Mo2N or Mo2C. The thermolysis reactions have been monitored using 1H NMR spectroscopy, and the volatile decomposition products were analyzed using gas chromatography-mass spectrometry. A key intermediate has also been detected using electron ionization high-resolution mass spectrometry. Finally, a detailed computational investigation supports the mechanism outlined above and helps explain the relative stabilities of different N,N'-chelated bis(alkylimido)-dichloromolybdenum(VI) adducts.

Electrochemical performance of high voltage LiNi0.5Mn1.5O4 based on environmentally friendly binders

The extended cyclability of LiNi0.5Mn1.5O4 (LNMO) electrodes featuring different water-based binders is here reported. LNMO electrodes with guar gum (GG) binders show a relatively stable cycle performance at 0 °C and room temperature. However, water-based binders exhibit higher capacity fade than those with polyvinylidene fluoride (PVdF) binder at 50 °C. Although PVdF binder has a lower adhesion force than CMC and GG; PVdF-based electrodes exhibit better capacity retention than those with water-based binders at 50 °C over 1000 cycles. Finally, operando Differential Electrochemical Mass Spectrometry (DEMS) experiments were carried out to analyze the evolution of volatile decomposition products formed over cycling at 1C and 30 °C of CMC-, GG- and PVdF-based LNMO electrodes. CO2 and H2 gas evolutions increase remarkably at both high temperatures and high potentials, i.e., ~ 4.7 V.

Stability of TMA-TEMPO-based aqueous electrolytes for redox-flow batteries

The TEMPO scaffold is one of the most prominent used posolyte systems in organic redox flow batteries (RFBs). While the aminoxyl radical is well known for his extraordinary stability, there are only a few studies investigating the stability of the respective oxoammonium cation. In this study, we utilize battery experiments to quantify the fade rate of the oxoammonium cation derived from N,N,N-2,2,6,6-heptamethylpiperidinyloxy-4-ammonium chloride (TMA-TEMPO) in correlation with temperature and time. The observed capacity decay is mostly caused by a deactivation of the oxidized TMA-TEMPO yielding the corresponding hydroxylamine, which can mostly be regenerated by reoxidation. Additionally, unbalanced compositionally symmetric flow cells are used to compare the fade rate at different temperatures combined with varying hold times showing a strong dependency on temperature and residence time in high states of charge. The acquired results are used for a use-oriented cycling program comprising a single cycle per day. Furthermore, GC-HRMS and isotopic labeling are used to analyze the volatile decomposition products of heated and oxidized TMA-TEMPO, identifying key intermediates of the decomposition mechanism and the role of an aqueous environment.

Characterization of Metal-Bound Benzimidazole Derivatives, Effects on Tumor Cells of Lung Cancer.

Four new ligands and four new copper (II) coordination compounds were prepared and characterized by chemical, elemental analysis, cytotoxicity, and FTIR spectroscopy (Fourier transform infrared spectroscopy). The nature of metal–ligand coordination was investigated. The thermal properties of complexes in the solid state were studied using TG-MS techniques (thermogravimetric analysis coupled with mass spectrometry) under dynamic flowing air atmosphere to analyze the principal volatile thermal decomposition and fragmentation products that evolved during thermolysis. The intermediate and final solid thermolysis products were also determined. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide) assay was used to evaluate active metabolic cells as an IC50 (half maximal inhibitory concentration). The relationship between antitumor activity and the position of nitrogen atoms in the organic ligand has been shown.

Effect of Different Synthesis Approaches on Structural and Thermal Properties of Lanthanide(III) Metal\u2013Organic Frameworks Based on the 1H-Pyrazole-3,5-Dicarboxylate Linker

The impact of different synthetic procedures such as: hydrothermal, mechanochemical and precipitation on the structure and thermal properties of coordination polymers of 1H-pyrazole-3,5-dicarboxylic acid (H3pdca) with selected lanthanide ions was determined. The prepared complexes of the general formula: Ln2(Hpdca)3⋅nH2O, where Ln = Eu(III), Nd(III), Tb(III) and Er(III); n = 6 or 7 were fully investigated by: elemental analysis, Energy-Dispersive X-Ray (ED-XRF) and infrared (ATR-FTIR) spectroscopy, powder as well as single-crystal X-ray diffraction methods and thermal analysis (TG-DSC and TG-FTIR) in various atmospheres. It was proved that all used strategies offer high yields of reactions along with crystallinity of the obtained products. The X-ray diffraction methods allowed to conclude that the complexes with the same metal ions exhibit the same crystal structure despite different synthesis routes. On the other hand, the coordination polymers of Eu(III), Tb(III) and Er(III) prepared under different conditions are isomorphous. Only neodymium(III) compounds have a different crystal structure. Thermal stability of the produced complexes was correlated with the synthesis conditions, in particular with the way of energy supply. It was found that the highest thermal stability was exhibited by the complexes prepared under the hydrothermal conditions. Additionally, based on the volatile products of metal complexes decomposition, the mechanism of their pyrolysis was proposed in relation to their structures.

The Effect of Halloysite Nanotubes on the Fire Retardancy Properties of Partially Biobased Polyamide 610.

The main objective of the work reported here was the analysis and evaluation of halloysite nanotubes (HNTs) as natural flame retardancy filler in partially biobased polyamide 610 (PA610), with 63% of carbon from natural sources. HNTs are naturally occurring clays with a nanotube-like shape. PA610 compounds containing 10%, 20%, and 30% HNT were obtained in a twin-screw co-rotating extruder. The resulting blends were injection molded to create standard samples for fire testing. The incorporation of the HNTs in the PA610 matrix leads to a reduction both in the optical density and a significant reduction in the number of toxic gases emitted during combustion. This improvement in fire properties is relevant in applications where fire safety is required. With regard to calorimetric cone results, the incorporation of 30% HNTs achieved a significant reduction in terms of the peak values obtained of the heat released rate (HRR), changing from 743 kW/m2 to about 580 kW/m2 and directly modifying the shape of the characteristic curve. This improvement in the heat released has produced a delay in the mass transfer of the volatile decomposition products, which are entrapped inside the HNTs’ lumen, making it difficult for the sample to burn. However, in relation to the ignition time of the samples (TTI), the incorporation of HNTs reduces the ignition start time about 20 s. The results indicate that it is possible to obtain polymer formulations with a high renewable content such as PA610, and a natural occurring inorganic filler in the form of a nanotube, i.e., HNTs, with good flame retardancy properties in terms of toxicity, optical density and UL94 test.

Inhibition Effect and Mechanism of Thiourea on Electrophilic Chlorination of Aromatics in Combustion Flue Gas.

Thiourea can effectively inhibit the formation of highly toxic chlorinated aromatics in postcombustion zone. However, the inhibition mechanism was still not adequately understood. In this study, naphthalene was adopted as a model aromatic compound to investigate the inhibition effect and mechanism of thiourea on the formation of chlorinated aromatics via electrophilic chlorination over Cu and Fe chlorides. Thiourea addition resulted in the reductions of 77.6-99.8% and 36.4-98.1% in the yield of polychlorinated naphthalenes from naphthalene chlorination mediated by CuCl2 and FeCl3 at 150-300 °C, respectively. The inhibition efficiency of chlorination presented a decreasing tendency with increasing reaction temperature and O2 content in flue gas. X-ray diffraction analysis revealed that the thiourea-induced reduction of highly active Cu (II) and Fe (III) chlorides to less active Cu (I) and Fe (II) chlorides was a primary mechanism for inhibiting aromatic chlorination. [thiourea-Cu]+ complex generated during the reduction process could be transformed into CuS and Cu2S, and isomeric reaction product NH4SCN could react with Cu2+ to produce Cu(SCN)2 and then also form Cu sulfides, suggesting sulfidization of Cu chloride was another important inhibition mechanism. Chlorination inhibition induced by the volatile decomposition products of thiourea might only play a minor role.

Structural changes of Nd- and Ce-doped ammonium diuranate microspheres during the conversion to U1−yLnyO2±x

The structural changes of ammonium diuranate (ADU) microspheres, prepared by the sol–gel route via internal gelation, were investigated during thermal treatments in oxidative and reducing conditions. In particular, in-situ simultaneous thermogravimetric analyses and in-situ high-temperature scanning electron microscopy investigations were carried out on un-doped ADU microspheres, and ADU microspheres doped with 10 mol% neodymium or 10 mol% cerium. Calcination in air caused the surface of the particles to crack, but with increasing temperature up to 900 °C some healing, and additionally, shrinkage occurred. The extent of the fractures and the amount of shrinkage was, however, significantly more pronounced in a particle prepared with a tetravalent Ce precursor, as compared to particles prepared with a trivalent Nd or Ce precursor. The macroscopic behaviour could be related to the release of volatile decomposition products and the calcined compositions were identified as (Ln-doped) α−U3O8by X-ray powder diffraction. During thermal treatment in reducing conditions a transition from a (Ln-doped) α−U3O8phase to a (Ln-doped) UO2±x phase was observed. After exposure to a hydrogen containing gas mixture, this transition occurred rapidly in un-doped particles, and in particles prepared with trivalent Nd or Ce dopant precursors at 700 °C. Despite the fast reduction reaction, severe fractures appeared in the particles above temperatures of 850 °C, indicating that such behaviour is mainly attributed to sintering effects and less to the phase transition. In contrast, a more delayed reduction reaction was observed in particles prepared with a tetravalent dopant precursor and the described effects appeared less severe.

Synthesis, Spectroscopic, Thermal and Catalytic Properties of Four New Metal (II) Complexes with Selected N- and O-Donor Ligands.

Four solid compounds with formulae: Co(OAc)2(Im)·H2O (I), Ni(OAc)2(Im)1.5·2H2O (II), Cu2(OAc)4(Im) (III) and Zn(OAc)2(Im)·H2O (IV) (where: Im = 1H-Imidazole) were prepared and characterized by chemical and elemental analysis, powder X-ray diffraction patterns and FTIR spectroscopy. Catalytic properties of each complex for styrene oxidation reaction were investigated. Furthermore, thermal properties of compounds were studied using the TG-DTG and DSC techniques under dry air atmosphere. Additionally, volatile thermal decomposition and fragmentation products were also investigated using the TG-FTIR spectra in air.

Incorporation of Vanadium(V) Oxide in Hybrid Hole Transport Layer Enables Long-term Operational Stability of Perovskite Solar Cells.

Recent studies have shown that charge transport interlayers with low gas permeability can increase the operational lifetime of perovskite solar cells serving as a barrier for migration of volatile decomposition products from the photoactive layer. Herein we present a hybrid hole transport layer (HTL) comprised of p-type polytriarylamine (PTAA) polymer and vanadium(V) oxide (VOx). Devices with PTAA/VOx top HTL reach up to 20% efficiency and demonstrate negligible degradation after 4500 h of light soaking, whereas reference cells using PTAA/MoOx as HTL lose ∼50% of their initial efficiency under the same aging conditions. It was shown that the main origin of the enhanced device stability lies in the higher tolerance of VOx toward MAPbI3 compared to the MoOx interlayer, which tends to facilitate perovskite decomposition. Our results demonstrate that the application of PTAA/VOx hybrid HTL enables long-term operational stability of perovskite solar cells, thus bringing them closer to commercial applications.

Fast sample preparation for organo(fluoro)phosphate quantification approaches in lithium ion battery electrolytes by means of gas chromatographic techniques

Lithium ion batteries are essential power sources in portable electronics, electric vehicles and as energy storage devices for renewable energies. During harsh battery cell operation as well as at elevated temperatures, the electrolyte decomposes and inter alia organo(fluoro)phosphates are formed due to hydrolysis of the conducting salt lithium hexafluorophosphate (LiPF6). Since these phosphorus-containing decomposition products possess a potential toxicity based on structural similarities compared to chemical warfare agents, quantification is of high interest regarding safety estimates. In this study, two comprehensive approaches for the precipitation of highly concentrated PF6¯ were investigated, allowing the separation from target analytes (organo(fluoro)phosphates) and improving mass spectrometry-based quantification techniques. Trimethyl phosphate was used as a polar, non-acidic organophosphate reference substance for method development via liquid chromatography-mass spectrometry. Six solvents were examined regarding precipitation reaction and selectivity. Thermally degraded electrolytes were analyzed after precipitation by means of gas chromatography-flame ionization detector, demonstrating the applicability of the developed sample preparations. The optimized method was applied successfully without influencing any volatile and non-acidic decomposition products. Using optimized conditions, a precipitation rate of 98% PF6¯ was achieved. Consequently, a fast and easy sample preparation for gas chromatographic investigations on lithium ion battery electrolytes was implemented, applicable for routine analysis.

New Features of Photochemical Decomposition of Hybrid Lead Halide Perovskites by Laser Irradiation.

We found that laser irradiation, being widely used in perovskite photovoltaics for both laser scribing and materials characterization, inevitably causes a cascade of complex photo- and thermochemical conjugated reactions, material melting, and ablation with deep morphological and composition changes of perovskite thin films over a much larger area compared to the initial laser spot. A crucial issue in the advancing or suppression of these degradation processes is related to the origin of the surrounding atmosphere. In particular, an effective approach utilizing an inert gas flow directed onto the exposed area is suggested for the first time to eliminate the negative consequences of perovskite laser scribing. This finding is naturally related to experimental observations of spreading the volatile decomposition products, including elemental iodine, over the pristine perovskite material, regardless of its composition, followed by laser-induced formation of liquid polyiodides. Suppression of decomposition product amount by proper selection of the gas atmosphere and power regime of the laser treatment is of interest to enhance the scribing procedure.

Evaluation of additively manufactured ultraperformance polymers to use as thermal protection systems for spacecraft

AbstractIn this study, high‐temperature thermoplastic polymers were three‐dimensional (3D) printed and evaluated for ablation performances for the first time. The purpose of this study is to fabricate, test, and evaluate several ultraperformance thermoplastics, including polyetherimide (PEI), polyether ether ketone (PEEK), and poly(ether ketone ketone) (PEKK) for thermal, flammability, and ablation properties using fused filament fabrication. Among all tested materials, PEKK exhibit the highest char yield while the two PEEKs exhibit the highest decomposition temperature. Although PEI have the lowest onset decomposition temperature, microscale combustion calorimetry results indicate that it has the lowest heat release properties. For the 15 s oxyacetylene test bed (OTB) ablation test, all five materials experienced various amount of intumescent or swelling behavior. Samples after 30 s test experienced greater mass loss among which PEKK and ULTEM 9085 shows the highest char yield. Scanning electron microscopy microstructural analysis of the char and pyrolysis zones reveal highly porous char structures caused by the rapid generation of the volatile decomposition products. To fully exploit the experimental data provided by the OTB, the flowfield generated during aerothermal testing using this heat source was modeled. Computational fluid dynamics analysis using Ansys/Fluent 19.1 code was used to the heat transfer between the ablative surface and the combustion gases generated by the OTB and compared with experimental results.