Kinetic Method Research Articles

Pyrolysis kinetics and reaction mechanism studies of 5-Amino-1H-Tetrazole with thermogravimetry/ differential scanning calorimetry/ Fourier transform infrared analysis

5-Amino-1H-Tetrazole (5AT) is extensively utilized in explosives, propellants and pyrotechnics as a high-nitrogen fuel or energetic material. Thermo-analysis is an efficient method to investigate the thermal decomposition characteristics of fuels or energetic materials, aiding in improving the safety and environmental performances of 5AT. In this study, the entire decomposition process of 5AT was explored using TG-DSC (thermogravimetry-differential scanning calorimetry) text. To accurately obtain the complete kinetic triplets, the iso-conversion activation energy for each stage was calculated using three conventional model-free approaches including KAS, Advanced Vyazovkin, and Starink methods, the results show that the activation energy results keep a good agreement by the three methods. Two different model-fitting methods (multiple heating rates CR method and the master-plots Criado method) were also introduced to predict the reaction model and calculate pre-exponential factors based on the iso-conversion activation energy results for the corresponding stages. The similarities and differences of the predicted results from these two different methods were compared, showing almost consistent findings that the first and third stages are controlled by the Fn and Dn model, respectively. Furthermore, the validity and the relationships were effectively verified and corrected based on the obtained kinetic parameters using the kinetic compensation effect, indicating the rationality of the selected kinetic methods and the calculated kinetic parameters for studying the pyrolysis characteristics of 5AT. Additionally, TG-FTIR (thermogravimetry combined with Fourier transform infrared) analysis was also conducted to identify characteristic groups and determine a potential pyrolysis pathway for 5AT. The findings in this paper can be used as input data for thermal safety, combustion, explosion and environmental protection model simulations.

Effect of curative in hydroxyl-terminated polybutadiene-based binder system on characteristic properties and kinetics of polymer-based energetic composite

ABSTRACT A series of polymer-based energetic composites (PEC) comprising 90% (by wt.) of crystalline octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) filler and 10% (by wt.) of hydroxyl-terminated polybutadiene (HTPB)-based binder system cured with different curing agents were prepared by cast cured technique. The effects of HTPB-based binder cured with different curing agents on the characteristic properties were investigated through different analytical and instrument techniques. The chemical stability was studied through vacuum stability tester apparatus at 100°C for 40 h. The results show that all energetic composites are chemically stable and compatible with each other. The results indicate that there is considerable variation in the impact and friction sensitivity with varying of the curing agents in the HTPB-based binder system. Thermogravimetric (TG) and differential scanning calorimetry measurements show that the thermal stability does not depend on the curing agents used. The detonation study outcomes show that the detonation performance of the composites is quite different, depending on the types of the curing agents used. The kinetic parameters for thermal decomposition were studied through the TGA methods at multiple heating rates by using the kinetic Ozawa, Kissinger, and Kissinger–Akahira–Sunose (KAS) methods. The PEC/TDI, PEC/IPDI, PEC/MDI, and PEC/TMDI samples showed average activation energies of 236.5, 208.7, 192.8, and 250.3 kJ/mol, respectively. These values are consistent and comparable to those obtained from other kinetic methods. However, the activation energy varies with varying the curing agent used in HTPB-based binder system.

Process of Magnetite Dissolution in Orthophosphoric and Sulfuric Acid Solutions According to Kinetic and Electrochemical Methods

Process of Magnetite Dissolution in Orthophosphoric and Sulfuric Acid Solutions According to Kinetic and Electrochemical Methods

Ab initio investigation of electronic structure and magnetic transformation during the bcc to hcp transition in Fe induced by pressure

The pressure-induced structural transition from a body-centered cubic (bcc) to a hexagonal close-packed (hcp) crystal in Fe is studied through ab initio electronic structure calculations, combining with the thermodynamic and kinetic phase-transition methods. According to the energy-volume relationship and thermodynamic criterion, the reasonable phase transition pressure is calculated to be about 13.88 GPa. The SSNEB method is employed to examine kinetic structural and barrier changes along bcc-hcp transition under various pressures. The transformation path involves the deformation of (110)bcc into the tightly packed (0001)hcp, accompanied by the relative slip of (110)bcc along the [1̅10]bcc direction, leading to the formation of the hcp structure. Our results indicate a reduction in the transition barrier of bcc-hcp with increasing pressure. Under the thermodynamic phase transition pressure, the bcc-hcp phase transition barrier is still as high as 140 meV, implying that pure hydrostatic pressure is not a sufficient condition to drive the phase transition. In addition, different from the continuous change of volume, the magnetism of the structure undergoes a magnetic mutation at the transition state, and the phase transition process involves complex magnetic transitions.

Eco-friendly zinc-metal-organic framework as a nucleating agent for poly (lactic acid)

Eco-friendly poly(L-lactic acid) (PLA) can be made more versatile, and its crystallization rate is accelerated by adding Zinc-based metal-organic framework (Zn-MOF) particles. Using differential scanning calorimetry (DSC), the non-isothermal melt crystallization behavior of biodegradable PLA nucleated by 0.3 to 3 wt% of Zn-MOF was examined. The non-isothermal melt crystallization kinetics parameters were determined using a modified Avrami model and Mo approach. Zn-MOF dramatically accelerated the crystallization process, as evidenced by several non-isothermal crystallization metrics, including the crystallization half-time and crystallization rate constant. The melt crystallization temperatures of the PLA-Zn-MOF composites, with contents of 0.7 and 1 wt%, were increased by 21 °C compared to the neat PLA. Using the Friedman isoconversional kinetic method, the neat PLA and PLA-Zn-MOF composites' effective activation energy values, ∆E, were determined. The ∆E values of PLA-Zn-MOF from 0.3 to 1 wt% Zn-MOF composites were lower than that of neat PLA. Moreover, polarized optical microscopy revealed the formation of numerous small-sized PLA spherulites upon Zn-MOF addition. The results indicate that the Zn-MOF (at concentrations of 0.7 to 1.0 wt%) can be used as an efficient nucleating agent for PLA, where it increases the melt crystallization temperature, nucleation density, and crystallinity without changing the crystalline structure, while also significantly reduces the effective activation energy and the size of spherulites. Additionally, scanning electron microscopy confirms good dispersion of Zn-MOF (0.3 to 1 wt%) within the PLA matrix.

Combustion Behavior of Cellulose Ester Fibrous Bundles from Used Cigarette Filters: Kinetic Analysis Study.

This study is focused on the detailed examination of the combustion properties and kinetic analysis of a cellulose acetate fibrous bundle (CAFB), separated from used cigarette filters. It was shown that the faster rate of CAFB heating allows a large amount of heat to be supplied to a combustion system in the initial stages, where the increase in heating rate has a positive response to ignition behavior. The best combustion stability of CAFB is achieved at the lowest heating rate. Through the use of different kinetic methods, it was shown that combustion takes place through two series of consecutive reaction steps and one independent single-step reaction. By optimizing the kinetic parameters within the proposed reaction models, it was found that the steps related to the generation of levoglucosenone (LGO) (by catalytic dehydration of levoglucosan (LG)) and acrolein (by breakdown of glycerol during CAFB burning-which was carried out through glycerol adsorption on a TiO2 surface in a the developed dehydration mechanism) represent rate-controlling steps, which are strongly controlled by applied heating rate. Isothermal predictions have shown that CAFB manifests very good long-term stability at 60 °C (which corresponds to storage in a sea shipping container), while at 200 °C, it shows a sudden loss in thermal stability, which is related to the physical properties of the sample.

Analytical methods for stable isotope labeling to elucidate rapid auxin kinetics in Arabidopsis thaliana.

The phytohormone auxin plays a critical role in plant growth and development. Despite significant progress in elucidating metabolic pathways of the primary bioactive auxin, indole-3-acetic acid (IAA), over the past few decades, key components such as intermediates and enzymes have not been fully characterized, and the dynamic regulation of IAA metabolism in response to environmental signals has not been completely revealed. In this study, we established a protocol employing a highly sensitive liquid chromatography-mass spectrometry (LC-MS) instrumentation and a rapid stable isotope labeling approach. We treated Arabidopsis seedlings with two stable isotope labeled precursors ([13C6]anthranilate and [13C8, 15N1]indole) and monitored the label incorporation into proposed indolic compounds involved in IAA biosynthetic pathways. This Stable Isotope Labeled Kinetics (SILK) method allowed us to trace the turnover rates of IAA pathway precursors and product concurrently with a time scale of seconds to minutes. By measuring the entire pathways over time and using different isotopic tracer techniques, we demonstrated that these methods offer more detailed information about this complex interacting network of IAA biosynthesis, and should prove to be useful for studying auxin metabolic network in vivo in a variety of plant tissues and under different environmental conditions.

Kinetic optimization of angkak – red ginger extraction and its impact on antioxidant activity

A mixture of angkak and red ginger is a Chinese herbal concoction with potential as an antioxidant. This herbal combination can be extracted using the kinetic hot maceration method by optimizing the stirring speed to be more efficient. Previous studies have shown that using 400, 600, and 800 rpm stirring speeds provides the best IC50 and yield. Based on these problems, this research aims to determine the effect of increasing stirring speed on IC50 and % yield in the extraction of angkak and red ginger, as well as prove the benefits of this herbal combination through the IC50 value. The method used is extracting a mixture of angkak and red ginger at kinetic variations of 400, 600, and 800 rpm using a magnetic hotplate stirrer at a temperature of 60ºC for 2 hours; determination of % yield; determining the chromatogram profile using TLC; determination of antioxidant activity using DPPH; as well as data analysis of percentage yield and IC50 using SPSS. Analysis using SPSS shows that the stirring speed significantly affects the % yield, where increasing the moving speed above 400 rpm results in a decrease in the % yield. However, the moving speed does not affect the IC50. The TLC chromatogram profile shows the presence of 6-gingerol compounds in angkak and red and yellow pigment compounds in red ginger, which have potential as antioxidants. The optimization results in this study obtained optimal % yield and IC50 at 400 rpm with average values, respectively, namely 15.933 ± 3.4771% and 103.76 ± 10.032 ppm, and the combination of angkak and red ginger ingredients can work synergistically to increase yield and antioxidant.

A kinetic partitioning method for simulating the condensation mass flux of organic vapors in a wide volatility range

Organic aerosols are ubiquitous, playing important roles in various atmospheric physicochemical processes such as the formation of cloud droplets and haze. Condensation of organic vapors, as a net effect of association with particles and dissociation from the condensed phase, is a fundamental process that drives the formation of organic aerosols. Kinetic models are often used to simulate the condensation fluxes of low-volatility organic vapors and aerosol growth. However, the widely used kinetic growth models usually calculate the evaporation of a certain species based on previous particulate compositions, without including the co-condensation of other species. Here we present a new kinetic partitioning method for calculating the condensation fluxes of organic vapors in a wide volatility range with low computational cost. In this method, the organic vapors are assumed to be in a quasi-steady state, but never reach real association-dissociation equilibrium during the simultaneous condensation of multiple species. We show a good consistency between the kinetic partitioning method and kinetic models in simulating particle mass fractions and condensation fluxes. Under relevant atmospheric conditions, we reveal that the kinetic partitioning method also reproduce the trend that low-volatility species are almost non-volatile while volatile organic compounds almost reach association-dissociation equilibrium, while there is a transition regime between them. This transition regime varies with atmospheric conditions, such as temperature and vapor concentrations. Compared with previous studies combining kinetic growth methods with equilibrium partitioning theories to simplify the condensation flux calculation, this method helps to improve accuracy without a significant expense of computation cost, and it can be applied in a wider range of atmospheric conditions such as in extremely cold atmospheres and polluted exhaust plumes.

Transient kinetics reveal the mechanism of competitive inhibition of the neutral amino acid transporter ASCT2

ASCT2 (alanine serine cysteine transporter 2), a member of the SLC1 (solute carrier 1) family, mediates Na+-dependent exchange of small neutral amino acids across cell membranes. ASCT2 was shown to be highly expressed in tumor cells, making it a promising target for anti-cancer therapies. In this study, we explored the binding mechanism of the high-affinity competitive inhibitor Lc-BPE with ASCT2, using electrophysiological and rapid kinetic methods. Our investigations reveal that Lc-BPE binding requires one or two Na+ ions initially bound to the apo-transporter with high affinity, with Na1 site occupancy being more critical for inhibitor binding. In contrast to the amino acid substrate bound form, the final, third Na+ ion cannot bind, due to distortion of its binding site (Na2), thus preventing the formation of a translocation-competent complex. Based on the rapid kinetic analysis, the application of Lc-BPE generated outward transient currents, indicating that, despite its net neutral nature, the binding of Lc-BPE in ASCT2 is weakly electrogenic, most likely because of asymmetric charge distribution within the amino acid moiety of the inhibitor. The pre-incubation with Lc-BPE also led to a decrease of the turnover rate of substrate exchange and a delay in the activation of substrate-induced anion current, indicating relatively slow Lc-BPE dissociation kinetics. Overall, our results provide new insight into the mechanism of binding of a prototypical competitive inhibitor to the ASCT transporters.

A reduced kinetic method for investigating non-local ion heat transport in ideal multi-species plasmas

A reduced kinetic method (RKM) with a first-principles collision operator is introduced in a 1D2V planar geometry and implemented in a computationally inexpensive code to investigate non-local ion heat transport in multi-species plasmas. The RKM successfully reproduces local results for multi-species ion systems and the important features expected to arise due to non-local effects on the heat flux are captured. In addition to this, novel features associated with multi-species, as opposed to single species, cases are found. Effects of non-locality on the heat flux are investigated in mass and charge symmetric and asymmetric ion mixtures with temperature, pressure, and concentration gradients. In particular, the enthalpy flux associated with diffusion is found to be insensitive to sharp pressure and concentration gradients, increasing its significance in comparison to the conductive heat flux driven by temperature gradients in non-local scenarios. The RKM code can be used for investigating other kinetic and non-local effects in a broader plasma physics context. Due to its relatively low computational cost it can also serve as a practical non-local ion heat flux closure in hydrodynamic simulations or as a training tool for machine learning surrogates.

Performance and Phase Change Kinetic Investigations on Capric-Myristic Acid Eutectic Mixtures for Energy-Saving Construction

In the present study, capric acid and myrisic acid were first selected to prepare a capric acid-myrisic acid eutectic mixture using a compounding method. Then, the thermal properties, structural stability and weight loss of capric acid-myrisic acid eutectic mixtures were analyzed using differential scanning calorimetry, Fourier transform infrared and thermogravimetry. Finally, the activation energy and reaction order of the capric acid-myrisic acid eutectic mixture during solid-liquid transformation were calculated using the phase change kinetic methods of Kissinger and Ozawa. The results indicate that capric acid-myrisic acid eutectic mixtures have good thermal cycle stability and stable energy storage in practical applications. The activation energies of capric acid-myrisic acid eutectic mixtures were calculated using the phase change kinetic methods of Kissinger and Ozawa, with values of 345.6 KJ/mol and 333.3 KJ/mol, respectively, indicating that both phase change kinetic methods have good accuracy.

Angiopoietin2 is associated with coagulation activation and tissue factor expression in extracellular vesicles in COVID-19.

Coagulation activation in immunothrombosis involves various pathways distinct from classical hemostasis, offering potential therapeutic targets to control inflammation-induced hypercoagulability while potentially sparing hemostasis. The Angiopoietin/Tie2 pathway, previously linked to embryonic angiogenesis and sepsis-related endothelial barrier regulation, was recently associated with coagulation activation in sepsis and COVID-19. This study explores the connection between key mediators of the Angiopoietin/Tie2 pathway and coagulation activation. The study included COVID-19 patients with hypoxia and healthy controls. Blood samples were processed to obtain platelet-free plasma, and frozen until analysis. Extracellular vesicles (EVs) in plasma were characterized and quantified using flow cytometry, and their tissue factor (TF) procoagulant activity was measured using a kinetic chromogenic method. Several markers of hemostasis were assessed. Levels of ANGPT1, ANGPT2, and soluble Tie2 correlated with markers of coagulation and platelet activation. EVs from platelets and endothelial cells were increased in COVID-19 patients, and a significant increase in TF+ EVs derived from endothelial cells was observed. In addition, ANGPT2 levels were associated with TF expression and activity in EVs. In conclusion, we provide further evidence for the involvement of the Angiopoietin/Tie2 pathway in the coagulopathy of COVID-19 mediated in part by release of EVs as a potential source of TF activity.

Technological Analysis of the Production of Nickel-Containing Composite Materials

The article presents the results of obtaining a composite material by sintering nickel-containing raw materials mixed with carbon-containing materials, namely using coke and semi-coke. The sintering process was performed at a charge layer height of 240 mm and the temperature of the lower layer was T = 1200 °C. The results of the sieve analysis showed (a fraction of 10 mm) that the yield of a suitable composite material using coke was 68.3% and with semi-coke 67.0%. The average nickel and chromium content in the composite materials was 1.42% and 3.07%, accordingly. As a result of determining the strength characteristics of the obtained composite materials with various reducing agents by dropping from a height of 2 m onto a steel pallet, it was found that the obtained composite materials have high mechanical properties in terms of strength of 81% and 89.2%. The results of the elemental composition at the studied points and the thermal analysis of the studied composite material are presented. The mineralogical composition of the composite material is presented in the form of serpentine and nontronite, and the empty rock is made of quartz and talc. The activation energy of thermal analysis by the method of non-isothermal kinetics were calculated. The results of experiments on the production of composite materials from nickel-containing raw materials will be recommended for obtaining the optimal composition of composite materials at the stage of pilot tests and industrial development of the developed technology for processing nickel ores of the Republic of Kazakhstan. For the processing of nickel-poor nickel ores, it is of great importance to obtain optimal technological and technical and economic indicators that ensure low cost of nickel in the resulting product.

Application of Model-Free and Model-Based Kinetic Methods in Evaluation of Reactions Complexity during Thermo-Oxidative Degradation Process: Case Study of [4-(Hydroxymethyl)phenoxymethyl] Polystyrene Resin

This work examined the possibilities and limitations of model-free and model-based methods related to decrypting the kinetic complexity of multi-step thermo-oxidative degradation processes (as a testing system, a [4-(hydroxymethyl)phenoxymethyl] polystyrene resin was used), monitored by thermal analysis (TGA-DTG-DTA) techniques. It was found that isoconversional methods could successfully determine the correct number of process stages and presence of multiple reactions based on derived Ea(α) profiles and identify the negative dependence of the rate constant on the temperature. These methods could not overcome the problem that arose due to mass transfer limitations. The model-based method overcame more successfully the problem associated with mass transfer because its calculation machinery had capabilities for the correct solution of the total mass balance equation. However, a perfect fit with the experimental data was not achieved due to the dependence on the thermal history of the contribution (ctb.) of a given reaction step inside a fitting procedure cycle. On the other hand, through this approach, it was possible to estimate the rate-controlling steps of the process regarding the influence of the heating rate. It was found that for consecutive reaction mechanisms, the production of benzaldehyde and gases in high yields was controlled by the heating rate, where low heating rates were strongly recommended (≤10 K/min). Also, it was shown that the transport phenomenon may be also the rate-determining step (within the set of “intrinsic” kinetic parameters). It was also established that external heat transfer controls the overall rate, where the “pure” kinetic control regime had not been reached but was approached when lowering the temperature and size of the resin particles.

Enantiodivergent kinetic resolution of 4-substituted 1,2,3,4-tetrahydroquinolines employing amine oxidase

Optically pure 1,2,3,4-tetrahydroquinolines (THQs) represent a class of important motifs in many natural products and pharmaceutical agents. While recent advances on redox biocatalysis have demonstrated the great potential of amine oxidases, all the transformations focused on 2-substituted THQs. The corresponding biocatalytic method for the preparation of chiral 4-substituted THQs is still challenging due to the poor activity and stereoselectivity of the available enzyme. Herein, we developed a biocatalytic kinetic resolution approach for enantiodivergent synthesis of 4-phenyl- or alkyl-substituted THQs. Through structure-guided protein engineering of cyclohexylamine oxidase derived from Brevibacterium oxidans IH-35 A (CHAO), the variant of CHAO (Y215H/Y214S) displayed improved specific activity toward model substrate 4-phenyl substituted THQ (0.14 U/mg, 13-fold higher than wild-type CHAO) with superior (R)-stereoselectivity (E > 200). Molecular dynamics simulations show that CHAO Y215H/Y214S allows a suitable substrate positioning in the expanded binding pocket to be facilely accessed, enabling enhanced activity and stereoselectivity. Furthermore, a series of 4-alkyl-substituted THQs can be transformed by CHAO Y215H/Y214S, affording R-isomers with good yields (up to 50 %) and excellent enantioselectivity (up to ee > 99 %). Interestingly, the monoamine oxidase from Pseudomonas fluorescens Pf0–1 (PfMAO1) with opposite enantioselectivity was also mined. Together, this system enriches the kinetic resolution methods for the synthesis of chiral THQs.

Evaluation of beta glucan test using kinetic turbidimetric method on toxinometer MT-6500 for detection of invasive fungal infections in hospitalized patients

Evaluation of beta glucan test using kinetic turbidimetric method on toxinometer MT-6500 for detection of invasive fungal infections in hospitalized patients

Kinetics and molecular modeling studies on the inhibition mechanism of GH13 α-glycosidases by small molecule ligands

Alpha-glucosidase inhibitors play an important role in Diabetes Mellitus (DM) treatment since they prevent postprandial hyperglycemia. The Glycoside Hydrolase family 13 (GH13) is the major family of enzymes acting on substrates containing α-glucoside linkages, such as maltose and amylose/amylopectin chains in starch. Previously, our group identified glycoconjugate 1H-1,2,3-triazoles (GCTs) inhibiting two GH13 α-glycosidases: yeast maltase (MAL12) and porcine pancreatic amylase (PPA). Here, we combined kinetic studies and computational methods on nine GCTs to characterize their inhibitory mechanism. They all behaved as reversible inhibitors, and kinetic models encompassed noncompetitive and various mechanisms of mixed-type inhibition for both enzymes. Most potent inhibitors displayed Ki values of 30 μM for MAL12 (GPESB16) and 37 μM for PPA (GPESB15). Molecular dynamics and docking simulations indicated that on MAL12, GPESB15 and GPESB16 bind in a cavity adjacent to the active site, while on the PPA, GPESB15 was predicted to bind at the entrance of the catalytic site. Notably, despite its putative location within the active site, the binding of GPESB15 does not obstruct the substrate's access to the cleavage site. Our study contributes to paving the way for developing novel therapeutic strategies for managing DM-2 through GH13 α-glycosidases inhibition.

Neutrophil to lymphocyte ratio (NLR) as a surrogate marker of diabetic nephropathy

Background and objectives: Diabetic nephropathy and retinopathy are microvascular complications of diabetes. Nephropathy is clinically manifested as an increase in urine albumin excretion. Total white blood cell count is a crude but sensitive indicator of inflammation and studied in many cardiac and non-cardiac diseases as an inflammatory marker such as acute myocardial infarction, stroke, and heart failure. In this study, the association of neutrophil to lymphocyte ratio (NLR) with diabetic nephropathy and retinopathy. Methods: This was a prospective observational study performed on patients with diabetic nephropathy +/- retinopathy. A total of v104 subjects diagnosed with 3type 2 diabetes mellitus registered in this study. NLR was calculated by analyzing differential leukocyte count in complete blood picture. Spot Albuminuria was tested by immune turbidimetry method. Urine creatinine was tested by jaffe’s kinetic method by which spot urine microalbumin to creatinine ratio is calculated. ANOVA, Independent t-test, chi-square test, Karl Pearson correlation were applied to find significance. P<0.05 was considered as statistically significant. Results: Totally 104 diabetic subjects were registered, 52 subjects had DN and 52 had normal urine albumin. Mean±SD NLR for a normal group is 2.5±1.1 and in DN group is 3.4±1.4 which was highly significant (P =0.001). Conclusion: Our study showed that there was a significant relation between NLR and DN; and positive correlation between NLR and urine microalbumin to creatinine ratio. Therefore, NLR may be considered as a novel surrogate marker of DN.

Influences of Sulfur-Containing Components on the Key Phases of FeS Spontaneous Combustion Dynamics

ABSTRACT In petroleum storage tanks, sulfur-containing crude oil continues to corrode equipment, generating sulfur corrosion products such as FeS. These products exhibit rapid exothermic reactions upon contact with air, thereby increasing the risk of fires and explosions. Additionally, sulfur monomers precipitated from sulfur or other compounds present in crude oil can adhere to FeS, consequently altering its spontaneous combustion characteristics. To explore the impact of associated sulfur content on the spontaneous combustion characteristics of FeS during its formation, this research synthesized FeS and its sulfur mixtures with sulfur concentrations of 5%, 10%, 15%, and 20%. These mixtures were prepared using a liquid-phase method, which involved the synthesis of self-made active FeS followed by the addition of different sulfur components. Differences in the spontaneous combustion characteristics of the five groups of samples were investigated in stages by simultaneous thermal analysis. The trends of the characteristic parameters of spontaneous combustion of FeS with different percentages of sulfur-containing components were analyzed. Finally, the apparent activation energy values of FeS with FeS and its associated sulfur were calculated by using thermodynamic analysis in the room-temperature spontaneous combustion stage (RT-75℃) and high temperature combustion stage (160–250℃). The findings indicate that the presence of sulfur components enhances the reactivity of FeS, yet reduces its oxygen absorption saturation threshold, thus advancing the oxygen absorption endpoint and facilitating entry into the high-temperature combustion stage. Moreover, FeS and its associated sulfur exhibit prolonged sustained combustion times when the sulfur component percentage is below 10%, favorably influencing the combustion behavior of FeS. As the percentage of sulfur component increases (from 10% to 20%), the combustion duration temperature rises from 60°C to 95°C. Additionally, an increase in the percentage of sulfur component (from 10% to 20%) leads to a higher combustion temperature. The activation energies of the five samples were determined using the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) kinetic methods. During the room temperature spontaneous combustion stage, the activation energy increases from 65.05 kJ/mol to 112.44 kJ/mol as the percentage of sulfur component rises from 0% to 20%. During the high temperature combustion stage, the activation energy increased from 108.32 kJ/mol to 214.49 kJ/mol with the increase in the percentage of sulfur component. FeS and its associated sulfur necessitate energy to propel the process due to heat absorption from the melting of sulfur monomers. As the reaction progresses into the high temperature stage, the required activation energy escalates accordingly.