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In this research, three kinds of imidazole ionic liquids were selected as the research objects. Among them, 1-butyl-3-methyl-imidazole bis(trifluoromethylsulfonyl)imine ([BMIM][Tf2N]) was used for gas adsorption, while 1-butyl-3-methyl-imidazole acetate ([BMIM][Ac]) and 1-butyl-3-methyl-imidazole tetrafluoroborate ([BMIM][BF4]) were used as extractants to replace traditional organic extractants. The thermal stability of three selected ionic liquids was studied, and their decomposition pathway and thermal stability were compared to explore the correlation between them. Thermal decomposition characteristic of [BMIM][Ac], [BMIM][BF4], and [BMIM][Tf2N] was analyzed by thermogravimetric analysis. For these three ILs, dynamic thermogravimetric analyses under nitrogen atmosphere were performed using thermal gravimetric analyzer. The TG curve shows that the order of short-term thermal stability of three ionic liquids is [BMIM][Ac] < [BMIM][BF4] < [BMIM][Tf2N]. Both Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods were used to analyze the thermal dynamics of the experimental process. The apparent activation energies calculated by two different kinetic methods of the three ILs also have some slight differences. The possible influence of the decomposition mechanism on thermal stability was analyzed by thermogravimetric coupled with Fourier-transform infrared spectrometry (TG-FTIR). After analyzing the experimental results, it is obvious that as the thermal stability of ionic liquids increases, their decomposition mechanisms become more and more complex. [ABSTRACT FROM AUTHOR]

Coal spontaneous combustion (CSC) has been endangering the safety of the coal industry. Spontaneous combustion of coal may lead to coal seam combustion and gas explosions in coal mines, causing a lot of damage. At the same time, CSC will produce a large amount of carbon dioxide, which seriously endangers the ecological environment. Therefore, what reduces the spontaneous combustion of coal is necessary. Ionic liquid (IL) is a new kind of green organic solvent. It has the characteristics of good stability and can be used as a flame retardant for CSC. In this study, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (Bmim[Ntf2]) was selected as the flame retardant of bituminous coal spontaneous combustion, where thermal stability of bituminous coal treated by Bmim[Ntf2] and raw bituminous coal was studied by the simultaneous thermogravimetric analyzer. The apparent activation energy was calculated by the FWO method. The decomposition gas products of bituminous coal and bituminous coal treated with Bmim[Ntf2] were analyzed by Fourier-transformed infrared spectrometer to investigate the effect of intramolecular hydrogen bond on bituminous coal spontaneous combustion. The results show that Bmim[Ntf2] inhibits the spontaneous combustion of bituminous coal. The addition of Bmim[Ntf2] increases the decomposition temperature of bituminous coal, where the apparent activation energy is increased. The results of Fourier-transformed infrared spectrometry show that the reduction in hydrogen bonds reduces the risk of spontaneous combustion of bituminous coal. [ABSTRACT FROM AUTHOR]

In plastic industry, liquid organic peroxides are prevailingly used to manufacture polymer materials. Unfortunately, a corresponding diversity of thermal hazards about instrument damage, fire, explosion, economic loss, and even casualty is engendered. This study focused on the comprehensive investigation to detect the specific thermal reactions and decomposition characteristics of tert-butyl (2-ethylhexyl) monoperoxy carbonate (TBEC) which is commonly used as polymerization initiator. First, simultaneous thermogravimetric analyzer was used to record the data in dynamic heating experiments and two mass loss stages were observed of TBEC. To further estimate the thermal stability of TBEC, differential scanning calorimetry was adopted to collect the thermokinetic parameters. Moreover, Flynn–Wall–Ozawa and ASTM E698-16 kinetic methods were applied for calculating the apparent activation energy of TBEC with different conversion rates. Then, thermogravimetric analyzer and FTIR spectrometer were utilized to detect the gaseous decomposition products of TBEC. The results show that TBEC is a Class 2 hazardous substance with high explosion hazard. The gaseous decomposition product of TBEC is tert-butyl alcohol, carbon dioxide, and 2-ethylhexanol. Furthermore, numerical simulation was employed to obtain the time to maximum rate under the adiabatic conditions of TBEC which can provide a predictive model for the industry. On the other hand, the explosion possibility of TBEC was assessed via oxygen balance. The findings of this study can provide the thermal hazard information of TBEC under upset scenarios and used to develop an instruction system to peter the related incidents. [ABSTRACT FROM AUTHOR]

Polystyrene is a multifunctional plastic used to manufacture consumables with a wide range of applications. Some azo compounds can produce free radicals when heated, which can be used as initiators for styrene polymerization. However, thermal runaway could occur during the styrene bulk polymerization initiated by azodiisobutyronitrile (AIBN) due to the release of a large amount of heat. To obtain thermal hazard properties, differential scanning calorimetry (DSC) and accelerating rate calorimetry (ARC) were applied to this investigation. The DSC experimental results showed that the extrapolated onset temperature and exothermic peak temperature decreased gradually after adding the initiator, which indicated initiator AIBN promoted the polymerization. ARC experiment decoded dynamic thermal parameters such as apparent activation energy, adiabatic temperature rise, initial runaway temperature, maximum temperature and polymerization heat of the hybrid system. Finally, the experimental and calculation results showed that the heat released by the polymerization reaction was basically unchanged at different heating rates; as the initiator concentration increases, the heat released by the polymerization reaction also increases, the polymerization temperature is controllable below 35.1 ℃. These results are critical for reducing the risk of loss of control and designing intrinsically safer styrene production, storage and transport processes. [ABSTRACT FROM AUTHOR]

Organic peroxides combined with ionic liquids had a high application value in the desulfurization process. However, thermal stability between organic peroxides and ionic liquids displayed a significant difference. Moreover, it was of great significance to investigate the thermal hazard of organic peroxides due to the influence of ionic liquids. In this study, a common organic peroxide cumene hydroperoxide (CHP) and two imidazole ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([Bmim]BF4 and Bmim[NTf2]), with good desulfurization performance were selected for experiments. The thermal stability of [Bmim]BF4 and Bmim[NTf2], respectively, mixed with cumene hydroperoxide in air and nitrogen conditions was studied by thermogravimetry (TG) analysis. The kinetic data of CHP which was mixed with two ionic liquids were evaluated using two different isoconversional methods: Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS). Furthermore, their gas decomposition products were investigated by thermogravimetry coupled with Fourier-transform infrared spectroscopy (TG-FTIR) analysis. The experimental and calculated results demonstrated that the apparent activation energy was decreased after CHP was mixed with the two ionic liquids. The main decomposition stage ranged from 350.0 to 480.0 K with a mass loss of CHP under air and nitrogen conditions. The thermal decomposition behavior of the CHP under air conditions displayed higher apparent activation energy compared with that in nitrogen atmosphere. The experimental results provide an important reference for organic peroxides combined with ionic liquids applicated in the desulfurization process. [ABSTRACT FROM AUTHOR]

1-Butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) is often used as an extractive desulfurization of liquid fuels. However, the role of air and nitrogen atmospheres on thermal effect of [Bmim]BF4 has been shown to the opposite. Thus, the effect of oxidizing gases on thermal stability and safety risk of [Bmim]BF4 is worth further investigation. In this study, the thermal stability, decomposition mechanism, and thermal hazards of [Bmim]BF4 were studied by thermogravimetric (TG), simultaneous application of thermogravimetric with a Fourier transform infrared spectroscopy (TG-FTIR), and accelerated adiabatic calorimetry (ARC). Obtained by thermogravimetric experiments, the long-term thermal stability of [Bmim]BF4 is MOT 8000 = 92 ℃ under air and MOT 8000 = 112 ℃ under nitrogen. TG-FTIR shows that the decomposition mechanism is different in the two atmospheres; CO2 is only produced under air, indicating that the decomposition products of [Bmim]BF4 undergo combustion and release huge heat, which explains the exotherm of DSC images in air. In adiabatic experiments, different atmospheres affect the decomposition reaction order of [Bmim]BF4. Nitrogen suppresses the thermal effect of [Bmim]BF4, because although the decomposition rate of [Bmim]BF4 before runaway is much greater under nitrogen than under air, the maximum temperature and maximum pressure are still less than under air. The thermal stability, thermal effect, and adiabatic runaway of [Bmim]BF4 in different atmosphere are a typical representations of ILs, which proves that oxidizing atmosphere has a great negative influence on thermal hazards of [Bmim]BF4. [ABSTRACT FROM AUTHOR]

The ionic liquid 1-butyl-3-methylimidazolium dicyanamide ([Bmim][Dca]) is a novel solvent suitable for a wide range of applications in the petrochemical industry. However, the thermal safety of [Bmim][Dca] IL has not been fully considered when developing new uses, especially in areas involving high-temperature work. Starting from the initial decomposition temperature of [Bmim][Dca] IL, this article tries to find the highest temperature suitable for its intrinsic safety and provides a basis for its industrial production. The thermal stability of [Bmim][Dca] IL and its pyrolysis gas detection were obtained by simultaneous thermogravimetric analyser (STA) and thermogravimetric analysis coupled with Fourier infrared spectroscopy (TG-FTIR), respectively. Furthermore, the constant temperature experiments by STA show that the mass loss of [Bmim][Dca] IL at a specific temperature for 10 h is approximately 2% at 160 °C, about 15% at 190 °C, and more than 30% at 210 °C. The mass loss in the dynamic heating experiment is divided into two steps at each heating rate. The pyrolysis gas detection experiments by TG-FTIR show that extremely toxic gas such as HCN will be produced at 154 °C (T0.01/10 h). The real-time photography system by STA observed significant colour changes in samples at this temperature. Therefore, extrapolated temperature (TMOT,10 h,e) was defined to obtain a more accurate maximum operation temperature. Comparative experimental results show that the TMOT,10 h,e obtained by the extrapolation method has high reliability. The results of this study would provide a relevant basis for safer control based on the thermal hazard assessment of [Bmim][Dca] IL. [ABSTRACT FROM AUTHOR]

4,4′-Azobis (4-cyanovaleric acid) (ACVA) is known as a kind of water-soluble azo initiator which was widely used in the radical polymerization process. As same as other azo compounds, ACVA may also trigger thermal runaway accidents at high temperatures due to its specific –N=N– structure. To qualify its pyrolysis characteristics, thermogravimetric analysis and differential scanning calorimetry were applied to this investigation, moreover, the TGA-FTIR combination technology was used in the product analysis part. The results showed that ACVA has a complex decomposition process, there are four mass loss stages during its pyrolysis, the heat release mainly occurred in the first and final decomposition stage and the heat flux in the middle stages was very disordered. Different decomposition stages were accompanied by different decomposition products, and some of them were considered toxic, such as HCN and CH4. Thermokinetic parameters such as apparent activation energy (Ea) were also calculated in this paper by using Kissinger–Akahira–Sunose (KAS) method. Surprisingly, ACVA has the lowest Ea (91 kJ mol−1) and the highest heat release (4706 J g−1) compared with some commonly used azos, which means it will more easily suffer a serious runaway accident. All these studies can give us a comprehensive understanding of the thermal decomposition of ACVA to prevent accidents. [ABSTRACT FROM AUTHOR]

Due to their low volatility, ionic liquids (ILs) are widely used in many industries. However, some ILs are reported to be explosive under unstable conditions in the literature, and therefore a comprehensive assessment of the fire safety risks should be conducted before industrial applications. This study aims to investigate the thermal stability of two environmentally friendly used ILs (1-butyl-3-methylimidazolium nitrate ([C4mim]NO3) and 1-butyl-2,3-dimethylimidazolium nitrate ([C4mmim]NO3) using simultaneous thermogravimetric analyzer, differential scanning calorimetry, accelerating rate calorimeter, and thermogravimetry coupled to Fourier transform infrared spectroscopy. Based on the results of dynamic and isothermal thermogravimetric experiments, [C4mmim]NO3 shows higher thermal stability compared with [C4mim]NO3, indicating that the methyl substitution at the imidazolium C2 has a positive effect on the thermal stability of imidazolium nitrate. Additionally, the increased methyl substitution leads to more significant thermal decomposition of [C4mmim]NO3 and enhanced gas production under adiabatic conditions, which means that the potential thermal hazards are increased. Furthermore, [C4mim]NO3 and [C4mmim]NO3 may have different thermal decomposition pathways because the possible thermal decomposition products are not identical. The produced flammable gases also indicate that the operating temperatures of [C4mim]NO3 and [C4mmim]NO3 must be strictly controlled to prevent the occurrence of accidents. [ABSTRACT FROM AUTHOR]

Organic peroxides, due to temperature manipulation failure and/or manner disturbances, had been probable to lead to the prevalence of runaway phenomena, even fire, and explosion. Cumene hydroperoxide (CHP), is a traditional liquid organic peroxide for industrial purposes and is applied as a free radical initiator for polymerization reactions in the petrochemical industry. Its utilization in the industrial processes had certain potential safety hazards. In this work, linearly ramped thermal decomposition in CHP was performed using differential scanning calorimetry under a nitrogen atmosphere. Kinetic analysis is made using data from the ramped measurements with two integral strategies (Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose). The gaseous products of thermal decomposition in CHP are investigated via thermal gravimetric evaluation coupled with Fourier transform infrared spectroscopy and gas chromatography/mass spectrometry. Combined with the experimental results, the possible decomposition path of CHP is discussed. This makes up the gap of unclear decomposition mechanism of CHP in inert atmosphere, and has important reference significance for its industrial production and application. [Display omitted] [ABSTRACT FROM AUTHOR]

As a new solvent with a broad prospect, ionic liquids (ILs) are widely used in catalysis, organic synthesis, and electrochemistry due to their peculiar physical and chemical properties. Nonetheless, their safety issues are often overlooked. This paper aims to decode the thermal reaction and decomposition hazard characteristics of ILs with an innovative method. Initially, the results of the thermal stability study of 1-n-butyl-3-methylimidazolium dicyanamide ([BMIM]DCN) using non-isothermal thermogravimetric and adiabatic analysis show that the decomposition process of [BMIM]DCN can be divided into three stages. By employing the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods, the apparent activation energy of decomposition was calculated and the stability of [BMIM]DCN was compared with structure-similar ILs (with the same imidazole cation). To predict the mechanism of [BMIM]DCN decomposition in the early stage, the products of the [BMIM]DCN under temperature-programmed conditions were analyzed by TG-FTIR, and a huge amount of toxic gases were detected in its decomposition products. In adiabatic tests, there is a sharp increase in pressure at about 382 °C, and the pressure of the system increases by about 12 times within 0.2 s. Furthermore, product analysis results show that the danger of the thermal decomposition of [BMIM]DCN is mainly due to the rapid pressure rise and toxicity caused by the massive gas products, such as HCN and NH3. The findings of this study can be used to develop thermal stability prediction models for similar ILs and provide the necessary foundation for the design and selection of precise processing methods and appropriate safety systems. [ABSTRACT FROM AUTHOR]

Azo compounds are widely used in polymerization as an initiator for chain polymerization reactions. Although they have excellent initiating properties, the thermal instability and associated risk of ignition and explosion cannot be ignored. This paper aimed to decode the thermal behavior and evaluation thermal hazards of two water-soluble azo initiators 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AIBA) and 2,2′-azobis(2-(2-imidazoline-2-yl) propane) dihydrochloride (AIBI). Thermogravimetric analysis and adiabatic experiments were used to investigate the decomposition process of these two azos under atmospheric and adiabatic conditions. The apparent activation energy (Ea) and time to maximum rate under adiabatic conditions (TMRad) were obtained based on above experiments. Decomposition products and mechanisms of AIBA and AIBI were preliminarily studied using a thermogravimetric analyzer coupled with Fourier transform infrared spectrometer system. Results showed that most decomposition products of AIBA and AIBI still existed in the form of organic compounds under nitrogen conditions. Furthermore, the leakage of pyrolysis gas (such as ammonia) should be prevented from causing environmental pollution. [ABSTRACT FROM AUTHOR]

1-Butyl-3-methylimidazolium nitrate ([C4mim]NO3) is a versatile and novel solvent for the gas separation industry. However, [C4mim]NO3 may cause explosions or other safety problems under upset scenarios. This study investigated the thermal hazard of [C4mim]NO3 using simultaneous thermogravimetric analyzer (STA), accelerating rate calorimeter (ARC), and thermogravimetry coupled with Fourier transform infrared spectroscopy (TG–FTIR). The initial thermal decomposition temperature of [C4mim]NO3 was 244.0 °C under adiabatic conditions, which was significantly lower than that under nonisothermal conditions. The maximum operation temperature of [C4mim]NO3 was also predicted based on the results of dynamic experiments. A critical runaway reaction of [C4mim]NO3 would be produced once heat accumulated according to the ARC tests. The exothermic pressure extended 34.0 bar within 3.8 s, which confirmed the vulnerability of [C4mim]NO3 to undergo a catastrophic explosion. Furthermore, the thermal decomposition mechanisms of [C4mim]NO3 were obtained based on the TG–FTIR results. These results are vital for designing inherently safer processes of [C4mim]NO3 production, storage, and transportation. [ABSTRACT FROM AUTHOR]

The thermal decomposition and runaway reaction of 1,3-dimethylimidazolium nitrate ([Mmim]NO 3), a typical nitrate IL, were studied by a simultaneous thermogravimetric analyzer (STA) and accelerating rate calorimeter (ARC). The STA results show that the thermal decomposition of [Mmim]NO 3 is divided into two stages, and the decomposition behaviour is similar in nitrogen or oxygen. The experimental results under adiabatic conditions indicate that [Mmim]NO 3 has higher T max and P max than other imidazolium ILs, which reflects the greater explosion hazard of [Mmim]NO 3. The apparent activation energies of [Mmim]NO 3 were 86 kJ/mol and 83 kJ/mol, as calculated by the F-W-O and K-A-S methods. The complete thermal decomposition gas products of [Mmim]NO 3 were analyzed by thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR), and the gas released by thermal decomposition of [Mmim]NO 3 does not react with oxygen. Therefore, the decomposition reaction of [Mmim]NO 3 was not positively related to the concentration of oxygen, which indicated that [Mmim]NO 3 could play an active role in the reactions in the presence of oxygen. The results of this study may provide theoretical and experimental basis for [Mmim]NO 3 safety precautions in storage and transportation. [ABSTRACT FROM AUTHOR]

Organic peroxide (OP) has been applied in the industry for at least 40 years. Driven by significant investments in today's high-profile energy, petrochemical, and polymer industries, the market and applications of OPs are expanding rapidly. However, the self-reactive nature has led to continuous research work on this topic. Nevertheless, tremendous progress has been made in hazard analysis, which has improved existing protocols or led to the discovery of new safety methods. OPs still cause related chemical hazards, and the limitations related to process hazards remain to be resolved. There is a lack of comprehensive systematic analysis of the process hazards of a wide variety of OPs. Different OPs, namely BPO, LPO, and the emerging OP, HTP-65W, were selected for investigation with several calorimetry techniques based on thermokinetic and heat transfer models. Determination methods have a crucial role in an operator for obtaining a systematic understanding of hazard properties under different process conditions, which is related to avoiding the occurrence of process disasters. For example, LPO has a shorter TMRad and TCL (< 1 min) than BPO and HTP-65W, indicating that LPO can be classified as an obvious hazardous material. Moreover, SADT < 25 °C can be used for evaluating LPO's cooling system efficiency. [ABSTRACT FROM AUTHOR]

Free radical polymerization is an effective method for large-scale production of various olefin polymers, in which the initiator is one of the emphases in the study of different chain reaction mechanisms in chemical industry. The azo compounds are widely used in organic synthesis to initiate chain reactions. Azos are divided into different types according to the applicable temperature range. 2,2′-Azobis(2-methylpropionitrile) is suitable for moderate temperatures and well known. In the past, the chemical and free radical reactions of 2,2′-Azobis(2-methylpropionitrile) have been studied. However, the kinetic model and reaction mechanism of initiators under process conditions are still lacking. The thermal hazard characteristics evaluated by process situation of 2,2′-Azobis(2-methylpropionitrile) were discussed in this study. The kinetics analysis on AIBN is based on detailed information including rate constants, reaction orders and activation energies of the decomposition reaction. Simulated heat exchange patterns of initiators between bulk packaging and the environment can be used to collect relevant heat hazard parameters. The results of the analysis are directly related to the storage and transportation safety of the 2,2′-Azobis(2-methylpropionitrile). Finally, a series of evaluation models about the thermal safety of initiators are constructed and analyzed by simulating the runaway modes of the 2,2′-Azobis(2-methylpropionitrile) at different temperatures. [ABSTRACT FROM AUTHOR]

Di-tert-butyl peroxy-hexahydro terephthalate (HTP-65W), a newly developed organic peroxide, has been used in manufacturing acrylonitrile–butadiene–styrene copolymer and as an initiator in the polymerization. However, few studies focus on the thermal hazards of HTP-65W. The purpose of this study was to investigate the thermal decomposition phenomenon of HTP-65W under different conditions via calorimetric technologies and simulation. According to simultaneous thermogravimetric analyzer curves, two mass loss stages were detected at about 79 °C and around 64–72% mass loss happened in the first stage. Furthermore, the real view system was used to observe the apparent physical phenomenon like color and state change in HTP-65W during the reaction. Utilizing accelerating rate calorimeter and adiabatic kinetic method, the exothermic phenomena occurred at around 75 °C. The apparent activation energy (Ea) and rate constant of reaction under adiabatic conditions were 172.0 kJ mol−1 and 4.0 × 1025 mol L−1 s−1. Through differential scanning calorimetry and kinetics simulation, an exothermic peak appeared between 87 and 168 °C caused by the thermal decomposition of HTP-65W, and the Ea calculated using Flynn–Wall–Ozawa and Friedman methods were 143.4 and 128.4 kJ mol−1, respectively. To prevent thermal loss prevention accidents, time to maximum rate under adiabatic condition was obtained as 24 h under 63.9 °C and self-accelerating decomposition temperature was 61 °C for 50 kg package size of HTP-65W. Results of this study can support to prevent the potential thermal hazards of HTP-65W happened during storage, transportation, and manufacturing process. [ABSTRACT FROM AUTHOR]

Melamine is one of the most extensively applied flame retardants due to its virtue of high thermostability, weak hydrophilicity, and low pollution. For the time being, its efficiency is hardly to be ideal when it acts alone. In previous explorations, melamine could be compellingly modified on the flame retardancy when it was blended with ionic liquids or the compounds comprising cyano groups. With the aim to integrate the advantages of both the groups of substances together, the cyano ionic liquid, 1-ethyl-3-methylimidazolium dicyanamide, was combined with melamine to improve the thermal stability of this widely used flame retardant in the research. The simultaneous thermogravimetric analyzer was applied to gain related parameters to determine whether the addition of the ionic liquid has the possibility to result in the increase in residue and the improvement in the thermal properties. Model-free and Coats-Redfern methods were related together to obtain the mechanism of decomposition. The experimental results demonstrate that the cyano ionic liquid possesses a promoting synergistic effect on the thermal behaviors of melamine, indicating its outstanding application prospect in practical utilization. [ABSTRACT FROM AUTHOR]

Organic peroxides (OPs) have a long history in the industry. In particular, it mainly occupies a leading position in the polymer industry, so there are still emerging substances being put into the current market and applications. However, the well-known aspect of OPs in the past is reflected in their self-reactive and hazardous properties, which have continued to expand related research in the field of safety. However, even under the rich research foundation and new safety technologies, the thermal hazards caused by emerging OPs are still heard, which means that the application of new OPs still needs attention and solutions in safety area. It is necessary to update the hazard knowledge of emerging OPs and achieve the purpose of disaster reduction. Therefore, the new OP, HTP-65W was selected for this study, starting from kinetic analysis and combining the heat transfer mode of the external system to estimate and assess the overall hazard characteristics between the material and the heat exchange of the environment. The basic experiment is carried out under the technical conditions of the isothermal calorimetric test which conformed to real situation. Evaluating the thermal hazard mode of a substance can establish the determination of safety parameters, and it is essential to the actual operation process. If the substance can be controlled at a specific ambient temperature or the decomposition reaction can be prevented, the possible hazards can be eliminated. For example, HTP-65W has shorter TMRad and TCL, which shows that HTP-65W has obvious reactivity hazards. In addition, evaluating the thermal hazards of HTP-65W in different containers can be used as a safety basis for the design of HTP-65W's cooling system and on-site operations. [ABSTRACT FROM AUTHOR]

Imidazoline ionic liquids (IMILs) because of its unique performance in the synthesis, liquid phase extraction environment, energy and other fields have broad application prospects, for the safety of the unknown material, study the thermal decomposition characteristics and potential hazards is very necessary. The purpose of this study was to evaluate the risk of three IMILs during production, transportation, storage, and application using thermogravimetry (TG) and accelerating rate calorimeter (ARC). The influence of different lengths of alkyl substituents on ILs stability was systematically analyzed. The apparent activation energy (Ea) and pre–exponential factor (A) of IMILs were calculated by Flynn–Wall–Ozawa (F–W–O) and Coats–Redfern (C–R) methods. Then, the mechanical function of their decomposition reaction was obtained by using the C–R method. The kinetic compensation effect is discussed. Finally, according to the experimental data under adiabatic condition by accelerating rate calorimeter (ARC), it is proved that the runaway reaction of the three IMILs is slow. This study confirms the low potential harmfulness of the above three microorganisms, gives their safe temperature range, and provides a reference for their safe use. [ABSTRACT FROM AUTHOR]

2,2′-Azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIBI) is a class of initiators that share water-soluble features, which was widely employed in the chemical polymerization industry. The merits of AIBI are that it can conduct smooth, stable, and controllable decomposition reaction and initiate polymerization efficiently at low temperature and concentration. Unfortunately, due to the high formation enthalpy and through a large amount of gas release, AIBI has high-potential thermal hazards. Therefore, the thermal behavior of the whole decomposition process is analyzed through series of simultaneous thermogravimetric analyzer and differential scanning calorimetry tests coupled with the advanced thermal investigation. It is found that AIBI would rapidly decompose and abruptly release an enormous amount of heat in the range of 170 to 180 °C, but with only 10% mass loss in this period. These thermal parameters can be used to describe the thermal stability of AIBI, thus effectively preventing the thermal hazard and loss of control of AIBI in the process of production, transportation, and storage. [ABSTRACT FROM AUTHOR]

Owing to splendid properties, trinitrophenol-based ionic liquid consisting of ammonium–imidazolium cation, 3,5-diamino-1,2,4-triazole picrate (DATPA), has been investigated concerning the thermal stability in this study. Differential scanning calorimeter (DSC) and thermogravimetry (TG) are used to explore the thermal behavior such as melting point, decomposition temperature, and the temperature of 10% mass loss which are the target to evaluate the thermal stability of other two picrates (picrate and 4-amino-1,2,4-triazole picrate). The results show that DATPA has better thermal stability at 251–252 °C than the other two picrates, and the melt volatility has decreased as well. Moreover, thermal kinetics parameters are calculated by changing the heating rates of DSC and TG. ASTM standard E698 and Kissinger methods are utilized to calculate, and double extrapolation is accepted to explore the mechanism function in the decomposition course, which has been defined as f (α) = 2.105 (1 - α) [ ln (1 - α) ] 0.525 in this study. Finally, an accelerating rate calorimeter is employed to study the thermal hazard of DATPA under the adiabatic condition and evaluate the level of runaway reaction through the risk matrix. According to Townsend method, we achieve the thermal kinetics parameters of DATPA under adiabatic condition. The results show that the apparent activation energy (Ea) of DATPA is 273.2 kJ mol−1 higher than many other explosives. Besides, according to the theoretical calculation, we find that DATPA has good detonation properties with high stability. [ABSTRACT FROM AUTHOR]

In this study, chitosan (CS) from fish waste was used to prepare bio-based environmentally friendly flame retardants. The hydroxyl group (-OH) of CS and the ammonium group (NH 4 +) of ammonium polyphosphate (APP) formed CS-APP, which was to serve as the core material. Melamine–formaldehyde (MF) resin was synthesized as the shell material through microencapsulation technology with CS-APP to prepare the novel core-shell structured flame retardant, which was subsequently introduced into polyurethane (PU) to prepare the composites. This study employed thermogravimetric analysis (TGA), the limiting oxygen index (LOI), UL-94, cone calorimetry tests (CCT), thermogravimetric analysis-FTIR (TGA-FTIR), SEM, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, smoke concentration test and tensile test to characterize the structure, thermal properties, flame retardancy, char analysis and mechanical properties of the composites. The TGA results revealed that after the addition of flame retardant, the char yield increased from 0.5 wt% (pristine PU) to 12.0 wt% (the composite), and the thermal stability of the pristine PU was improved. Furthermore, the LOI increased from 18.2 % to 28.4 %, and the UL-94 level increased from fail to V-0 for the composites. These results revealed that adding MF(CS-APP) to pristine PU resulted in high flame-retarding performance of the composites. [Display omitted] [ABSTRACT FROM AUTHOR]

• A new method was developed to study the thermal hazard of imidazole ILs. • The decomposition mechanism of ILs in different atmospheres was not affected. • The more complex the side chain was, the lower the thermal stability of the ILs. • Thermal decomposition in an air atmosphere releases more CO 2. Ionic liquids (ILs) are room temperature molten salts, have received extensive attention from the academic community due to their excellent characteristics. In the context of global warming, more and more scholars are looking forward to using ILs as a gas adsorbents, especially ILs containing bis(trifluoromethylsulfonyl)imine (Tf 2 N). It is well known that the thermal stabilities of ILs are affected by many factors, and the cation type is one of them. In this paper, five imidazole ILs with different functional groups on the side chains of the imidazole rings were selected as the research objects, and their anions were all Tf 2 N. The thermal decomposition characteristics and thermal effects of the selected samples were determined by thermal gravimetric analyzer (TGA) and differential scanning calorimetry (DSC). The experimental data showed that the most stable ionic liquid was that with the simplest side chain, and the more complex the side chain was, the lower the thermal stability of the sample. In addition, some of their decomposition products were studied with thermogravimetric analyzer coupled with Fourier-transform infrared spectrometry (TG–FTIR). The decomposition mechanisms of the samples did not change under different atmospheres. [ABSTRACT FROM AUTHOR]

2,2′-Azobis (2-methylpropionate) (AIBME) is a new type of environmental-friendly oil-soluble azo initiator, extensively applied in the radical polymerization industry relying on its extraordinary thermal and physicochemical properties. Nevertheless, the special structure makes AIBME decompose easily under low ambient temperature with a tremendous amount of heat release. To qualify its thermal hazard and obtain the specific safety parameters such as time to maximum rate under adiabatic condition (TMRad) and self-accelerating decomposition temperature (SADT), differential scanning calorimeter (DSC), simultaneous thermogravimetric analyzer (STA), and accelerating rate calorimeter (ARC) were applied to analyze the thermal behaviors of AIBME while conducting the thermokinetic analysis and numerical curve fitting. The results indicate that AIBME decomposes at low temperature, and the SADT of AIBME in 25 kg UN package is 35.2 °C. Moreover, the temperature at TMRad = 8 h is determined at 51.6 °C using Townsend method. Compared with commercially used azo compounds, such as 2,2′-azobisisobutyronitrile (AIBN) and 2,2-azobis(2-methylbutyronitrile) (AMBN)), the predominant heat of decomposition, more gaseous degradation products, quicker heat release rate, and lower decomposition temperature make AIBME more hazardous during production, storage, and transportation. The results of this study can provide the references for the process safety assessment and the design of appropriate safety system in scale-up applications with the wish to avoid the occurrence of AIBME involved accidents. [ABSTRACT FROM AUTHOR]

Severe fire and explosions are frequent phenomena during handling of organic peroxides that are promoted supremely by conditions such as chemical impurities and thermal instability. As an initiator in the polymerization process, cumene hydroperoxide (CHP) has wide usage in the chemical process industry. This violently reactive chemical is studied here experimentally using differential scanning calorimeter (DSC), an isothermal mode of operation that can access the thermal hazards in the decomposition of CHP alone and later mixed with products following an autocatalytic reaction scheme. Importantly, DSC-evaluated thermokinetic parameters such as reaction enthalpy (ΔHd), time to maximum rate (TMRiso), and maximum heat flow (Qmax) were estimated to ascertain the degree of thermal hazard under various transportation and storage temperatures. The Heat-Wait-Search mode of accelerating rate calorimeter has been used to investigate decomposition kinetics parameters data under an adiabatic condition. Data such as initial exothermic temperature (T0), self-heating rate (dT/dt), pressure rise rate (dP/dt) and pressure–temperature profiles help to gauge the runaway reaction hazard of CHP alone and then mixed with its products to support the autocatalytic model of exothermic decomposition. The curve fitting data indicated that activation energy had reduced from 245.4 to 236.7 and 242.3 kJ mol−1, when CHP was mixed with acetone or dicumyl peroxide, respectively. The decrease in activation energy for autocatalytic material thermal decomposition reaction is depicted here with various experimental findings and mathematical analysis. [ABSTRACT FROM AUTHOR]

• [C 2 mmim]NO 3 could cause an explosion or other hazard problems. • Various analysis instruments were applied to analyze the thermal stability. • Thermokinetic parameters were calculated by two isoconversional methods. • A homemade combustion test device was used to assess the flammability. • The possible combustion process of [C 2 mmim]NO 3 was determined. 1-Ethyl-2, 3-dimethylimidazolium nitrate [C 2 mmim][NO 3 ] is a typical solvent for industrial applications. Under inappropriate temperatures, [C 2 mmim][NO 3 ] may present a flammability hazard due to thermal decomposition. This study investigated the thermal stability and flammability of [C 2 mmim][NO 3 ] via simultaneous thermogravimetric analyzer, homemade combustion test device (CTD) with high speed camera, and thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR). The thermal decomposition of [C 2 mmim][NO 3 ] was divided into two parts based upon the dynamic experiments, and the maximum operating temperature was determined to comprehensively estimate the thermal stability of [C 2 mmim][NO 3 ]. CTD experiments indicated that [C 2 mmim][NO 3 ] could produce intense combustion when heated. Further TG-FTIR experiments confirmed that [C 2 mmim][NO 3 ] decomposed to produce a large number of flammable gases, such as ethylene, which might be the reason that [C 2 mmim][NO 3 ] has prominent flammability. [ABSTRACT FROM AUTHOR]

4-Amino-1,2,4-triazole picrate (4-ATPA) is synthesized to reduce the corrosiveness of picric acid (PA) to metals, which simultaneously maintains the detonation performance of PA and the advantages of 4-amino-1,2,4-triazole. In this work, the thermal stability of 4-ATPA is estimated using thermogravimetric analysis (TG) and accelerating rate calorimeter. The dynamic TG experimental results suggest that the onset temperature is at the range of 189.0–220.0 °C under different heating rates. The average apparent activation energy of 4-ATPA is 112.0 ± 1.1 kJ mol−1 using Flynn–Wall–Ozawa, Starink, and Kissinger methods based on the multiple heating rates. The isothermal TG experiments indicate that 4-ATPA will be decomposed 10.0% within 1 day if the temperature exceeded 150.7 °C and will be decomposed 10.0% within 10.0 h if the temperature exceeded 162.6 °C. The adiabatic tests depicted that the exothermic reaction initiates at 186.0 °C and a rises sharply at 306.7 °C with the maximum self-heating rate of 4775.5 °C min−1. The exothermic event is accompanied by a pressure rise of 39.7 bar, which confirms the vulnerability of 4-ATPA to undergo catastrophic explosion. [ABSTRACT FROM AUTHOR]

• Less studied thermal properties of ILs are explored. • A series of parameters are essential for mitigating the degree of thermal hazard. • The kinetic of reactions which often difficult to evaluate is determined. • A kinetic parameter application with thermal safety was identified in this work. • Experimental specification data can be applied to actual process. Using batteries to convert chemical energy into electrical energy is one of the significant technologies that must be enhanced in the 21 st century. In the fuel battery development area, ionic liquids (ILs) are outstanding electrolytes for batteries. According to their thermophysical and phase equilibrium properties, ILs are widely used in different energy fields due to their diversity in the synthesis field. However, there are few detailed thermokinetic studies on ILs. To ensure the thermal safety of ILs in the process of creation, a commonly used IL, 1-butyl-3-methylimidazolium nitrate ([Bmim]NO 3), was chosen for exploration. In this study, thermal decomposition characteristics were obtained by differential scanning calorimetry. The obtained data were input into the thermokinetic equation to determine the basic thermal hazards of [Bmim]NO 3. In addition, based on thermal equilibrium theoretical models, the reaction kinetics and critical safety parameters were extrapolated for consideration. The influences of the sample mass and the overall heat transfer coefficient were simulated and discussed in 25.0 g and 50.0 g packages. The results showed that [Bmim]NO 3 had a shorter TMR ad and TCL (<1 day) when the temperature was greater than 200 °C. Moreover, SADT< 150 °C can be used for evaluating the cooling system efficiency of [Bmim]NO 3. [ABSTRACT FROM AUTHOR]

4-Amino-1,2,4-triazole picrate (4-ATPA) is a type of ionic liquids, as well as an explosive with sound thermal stability and low mechanical sensitivity. However, under upset conditions such as high temperature and pressure, an unpredictable explosion would occur and result in huge casualties and property losses. The purpose of this research was to evaluate the thermal hazard and runaway reaction of 4-ATPA through high-pressure differential scanning calorimetry and accelerating rate calorimeter. The kinetic parameters of decomposition reaction under non-isothermal and different pressure conditions were calculated based on the experiment results. Experimental results showed that the β and test pressure had no effect on the amount of heat release. Adiabatic experiments indicated that 4-ATPA had a high onset temperature at 196.8 °C. The maximum self-heating rate (3567.9 °C min−1) and pressure rise rate (202.0 bar min−1) revealed the vulnerability of 4-ATPA to suffer a disastrous explosion. Moreover, the apparent activation energy and pre-exponential factor were evaluated as 110.2 kJ mol−1 and 1.8 × 10−15 s−1 by ASTM E698 method. The correctness of the thermodynamic calculation formula under adiabatic conditions is verified by ARC tests. Finally, the thermal hazard risk of 4-ATPA was classified as unacceptable based on the risk classification criteria. [ABSTRACT FROM AUTHOR]

Azo compounds (azos) are widely used as radical initiators in the polymerization industry. Nonetheless, due to the azo group molecular structure, azos gravitate toward thermal decomposition and lead to thermal runaway accidents. In this paper, the thermal decomposition behaviors of 2-(1-cyano-1-methylethyl)azocarboxamide (CABN) under the dynamic and adiabatic environments were investigated using differential scanning calorimetry and accelerating rate calorimeter. Several safety assessment parameters such as time to maximum rate under adiabatic condition (TMRad), temperature of no return, and self-accelerating decomposition (SADT) temperature were calculated based on thermokinetic analysis as well as curve fitting. The results indicated that CABN decomposes at low temperatures (90.0–100.0 °C) and releases huge volumes of gaseous products, which may set off a fire, deflagration, or even explosion if the decomposition occurs uncontrolled in a confined space. Compared with commonly used azos, the shorter TMRad, lower SADT, and more heat from thermal decomposition reflect the potential thermal explosion hazards of CABN. To investigate emergency response procedure in terms of industrial applications, the oxygen-balance method was further used to evaluate the explosion hazard of CABN, and several recommendations on alleviating the thermal hazards of CABN were established to prevent catastrophic accidents. [ABSTRACT FROM AUTHOR]

Azo compounds used in catalytic reactions often exhibit self-reactivity and high exothermicity. Severe fires and explosions can occur if the stage of change in the reaction (e.g., in an endothermic process or cooling system) is weaker than in a fractional heat release process. To guarantee the thermal safety of azo initiator in the production process, azobisdimethylvaleronitrile (ABVN), a normally applied azo in polymerization, was selected for the study. The basic thermal hazards of ABVN were obtained by simulating the exothermic curves of ABVN with differential scanning calorimetry technique, and the self-accelerating decomposition temperature (SADT) was calculated by combining the kinetics of the reaction. Analyzing the impact of different packaging conditions on SADT, values were verified with simulation methods performed with the packaging of 25.0 kg and 50.0 kg of ABVN. The results showed that the SADT was lower than 50 °C. Therefore, it is essential to establish a style of computing that can more rapidly determine the value of SADT, avoiding time-consuming and costly large-scale experiments. [ABSTRACT FROM AUTHOR]

Azo compounds, which are commonly used in radical polymerization reactions, readily demonstrate their self-reactive properties. Because of their sensitive thermal decomposition properties, azo compounds have been responsible for many accidents. To avoid unexpected thermal decomposition in the workplace, information about the thermal stability and other properties of azo compounds should be provided to on-site personnel in industries that use these materials. In this study, the target substance, 2,2'-azobis-(2,4-dimethylvaleronitrile) (ABVN), is shown to have a higher reactivity than other azo compounds, and its thermal decomposition characteristics are discussed based on a literature review and results from differential scanning calorimetry (DSC) and accelerating rate calorimetry (ARC). A thermokinetic analysis of ABVN is conducted using DSC and ARC data. The results can provide process-control data and explain the effects of thermal runway for ABVN. In addition, based on applied numerical methods, critical runaway temperatures, stable temperatures, and the required heat dissipation rate for the prevention of the thermal runaway reactions are calculated using a process deviation analysis. The results show that the reactant quantities and the process parameters must be strictly controlled to achieve the desired reaction. [ABSTRACT FROM AUTHOR]

• Using the results of laboratory scale analysis to confirm thermal hazards in plant. • Combing DSC and ARC to investigate the thermokinetics of ABVN. • Model-free prediction was employed to predict an adiabatic runaway reaction. • Critical conditions were revealed by the theoretical analysis. Azo compounds, which are commonly used in radical polymerization reactions, readily demonstrate their self-reactive properties. Because of their sensitive thermal decomposition properties, azo compounds have been responsible for many accidents. To avoid unexpected thermal decomposition in the workplace, information about the thermal stability and other properties of azo compounds should be provided to on-site personnel in industries that use these materials. In this study, the target substance, 2,2′-azobis-(2,4-dimethylvaleronitrile) (ABVN), is shown to have a higher reactivity than other azo compounds, and its thermal decomposition characteristics are discussed based on a literature review and results from differential scanning calorimetry (DSC) and accelerating rate calorimetry (ARC). A thermokinetic analysis of ABVN is conducted using DSC and ARC data. The results can provide process-control data and explain the effects of thermal runway for ABVN. In addition, based on applied numerical methods, critical runaway temperatures, stable temperatures, and the required heat dissipation rate for the prevention of the thermal runaway reactions are calculated using a process deviation analysis. The results show that the reactant quantities and the process parameters must be strictly controlled to achieve the desired reaction. [ABSTRACT FROM AUTHOR]

• Used the results of laboratory scale analysis to confirm thermal hazards in plant. • The kinetics of two azo compounds by thermal analysis was investigated. • Kinetic-based simulations were applied for evaluation of SADT for two azos. • Kinetic model on process condition was determined based on adiabatic data. • Thermal stability, such as TMR ad and SADT have been found using analytical models. As a key initiator of polymerization, azo compounds (azos) can supply abundant energy to the polymerization process. Although polymerization can be implemented more smoothly and the product can be modified, the use of azos also increases the probability of process hazards caused by high heat accumulation and release. To preserve the thermal safety of using azo initiators in the synthesis process, the frequently used azo initiators dimethyl 2,2′-azobis(2-methyl propionate) (AIBME) and 2,2′-azobis(2,4-dimethylvaleronitrile) (ABVN) were chosen for investigation. Under process conditions, initiators are essential for evolving and monitoring chemical reactions on both the laboratory scale and process environment. The assessment, control, and mitigation of reaction hazards are primarily based on kinetic models, which are used to estimate multiple critical safety parameters, such as TMR ad in process safety and TCL and SADT in storage and transportation operation. The data from the adiabatic calorimeter correspond to real process situations are combined with the nonlinear adiabatic kinetic model, which is rarely applied to analyze the thermal hazard properties of azos. The results indicated that the kinetic model of azos in the actual process, the thermal hazard characteristics, and simulation of the runaway mode of azos in setting boundary conditions should also be investigated. [ABSTRACT FROM AUTHOR]

Due to their numerous properties as an advanced or specialized material, ionic liquids (ILs) have found an increasingly wide utilization in many fields. Moreover, mixtures of ILs can further improve their correlative properties. Therefore, it is significant that the thermal stability and exothermic behaviour of IL binary mixtures were studied. In this work, two typical representative imidazole ILs ([BMIM]BF4 and BMIM[NO3]) were selected, and their binary mixture thermal stability and thermal decomposition process of visualization were investigated by simultaneous thermogravimetric analyser (STA). Furthermore, their binary mixture exothermic behaviour and decomposition products were obtained by differential scanning calorimetry (DSC) and thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR), respectively. The compound mode of imidazolium-based IL binary mixtures was divided into three categories: the molar fraction (7:3, 1:1, and 3:7) of parent pure ILs. We found that TG curves trend of IL binary mixtures was consistent with their parent pure ILs. Compared with TG curves, DSC curves of IL mixtures demonstrated that the behaviours of heat absorption and heat release at greater than 700.0 K in mixtures were different from their parent pure ILs. According to the infrared spectrum of gas products, the oxygen-containing functional group in BMIM[NO3] is likely to have some influence on the second-stage decomposition of sample 1#. Systematic thermal analysis results provided a significant reference for the exothermic behaviours and thermal degradation process of imidazolium-based ionic liquid binary mixture and a feasible research route for further investigations into the thermal decomposition characteristics of IL mixtures. [ABSTRACT FROM AUTHOR]

1,3-Dimethylimidazolium nitrate ([Mmim]NO 3), an ionic liquid, is a versatile and novel solvent for the petrochemical industry. Nevertheless, under high temperature conditions or thermal upset scenarios, [Mmim]NO 3 can be decomposed in a manner that produces an explosion or other serious safety problems. The aim of this research was to investigate the thermal stability of [Mmim]NO 3 by simultaneous thermogravimetric analyzer and high pressure differential scanning calorimetry. Isothermal experiments indicated that [Mmim]NO 3 would be decomposed at a temperature substantially lower than the onset temperature. A pseudo-zero-order rate expression was applied to characterize the thermal decomposition kinetics of [Mmim]NO 3 , and related thermokinetic parameters were further obtained. Moreover, the temperature at which the thermal decomposition of ILs reached 10.0% for a given time of 10.0 h (T 0.1/10h) was defined to assess the long-term thermal stability, which can be used as the maximum operating temperature of [Mmim]NO 3. The results of this study may provide relevant processes for safer control based on the thermal hazard assessment of [Mmim]NO 3. [ABSTRACT FROM AUTHOR]

In this study, the thermal stability and thermokinetic parameters of 1,3-dimethylimidazolium nitrate ([Mmim]NO3) were investigated by thermogravimetric analysis under non-isothermal conditions in a nitrogen atmosphere. The results showed that [Mmim]NO3 exhibited three decomposition stages from 93.3 to 350.0 °C, and the onset temperature of [Mmim]NO3 was obtained at approximately 161.0-182.0 °C under five heating rates. The apparent activation energy was 119.0-124.0 kJ mol−1, as calculated by different well-known equations, and the pre-exponential factor was 3.6 × 1012 min−1. The reaction mechanism of [Mmim]NO3 was carried out with the reaction order n = 1.0, and the decomposition mechanism function was further obtained. Moreover, vent sizing package 2 was employed to acquire the maximum self-heating rate (39,828.0 °C min−1) and pressure rise rate (73,331.0 psig min−1) for simulating cooling system failure in a practical process. The findings indicated that [Mmim]NO3 showed the possibility of a runaway reaction, leading to a potential thermal hazard. The approach of these results is vital for obtaining inherently safer process information for [Mmim]NO3 during production, storage, and transportation. [ABSTRACT FROM AUTHOR]

A flammable gas could be ignited only if its concentration in air is over a threshold concentration, which is known as the lower flammability limit (LFL). Therefore, predicting LFLs of flammable gases is indispensable for safely handling such flammable gases. The Le Chatelier’s mixing rule for the LFL is the prevailing method for estimating the LFLs of mixtures with multiple flammable components. In this work, a novel derivation for this rule is proposed based on the threshold temperature concept. It is found that the important assumption required to reach this mixing rule is that the adiabatic flame temperature rises at LFL are approximately the same for each flammable component. As the adiabatic flame temperature rise is in a sense the required energy gap to initiate a combustion, it should not change while adding/removing inert gas into/from the system. Therefore, it is also the required perquisite to predict the LFLs of inertized mixture or the LFLs in oxygen atmosphere. [ABSTRACT FROM AUTHOR]

Cosmetic products that contain malic, salicylic, hyaluronic acids and various antioxidants, which are popular worldwide, have made cosmeceuticals a popular cosmetic production sector. Typically, each component of cosmetics, regardless of its activity, may affect the thermal stability of the product. To investigate the thermal stability of regular cosmetics of interest, thermal activity monitor IV was applied to determine the thermokinetic parameters for stability assessment. Arrhenius equations and thermal safety software (for kinetic calculations and numerical simulations) were used. Considering the numerous additives in cosmetic products, individual components of cosmetic material mixed with other components are the primary factors for product deterioration. We examined samples of pure malic acid, pure salicylic acid, and individual acids mixed with copper or iron oxide under isothermal surroundings at 80, 90, 100, 110, and 120 °C. The results of isothermal tests were compared with nonisothermal tests using Arrhenius equations, ASTM E698 method, and Flynn-Wall-Ozawa methods. The value of Ea between malic acid and salicylic acid became lower when mixed with CuO. The findings can be used to identify the optimal parameters for product design and establish a malic and salicylic acid database for developing a proactive loss prevention protocol. [ABSTRACT FROM AUTHOR]

Di(2,4-dichlorobenzoyl) peroxide (DCBP), classified as a diacyl peroxide, is commonly used in silicone rubber manufacturing as a crosslinking agent, vulcanizing agent, and polymerization initiator. However, its reactivity or incompatibility may negatively affect safety requirements and concerns during chemical reactions. This study was conducted to investigate the properties of DCBP by using differential scanning calorimetry and a literature review. Specifically, thermal decomposition behavior of DCBP was examined by combining simulations with thermal analysis methods to analyze the foundation of thermokinetics, such as the peak temperature, heat of decomposition, and apparent activation energy of DCBP. Based on parameters obtained from the calculations, this investigation was integrated with thermal explosion theory, which represents a major advancement in the comprehension of behavior between heat release and heat transfer to the surroundings incorporated into a single differential equation, and a decision was made from a criticality criterion simultaneously. [ABSTRACT FROM AUTHOR]

• Kinetics model of CHP decomposition was created based on isothermal data. • Kinetics approach and appropriate heat balance for scale up simulation. • Safety parameters from results can provide information for loss prevention. • Kinetics parameters determined through model-fitting method. • Simulation method for SADT determination was confirmed. In the petrochemical industry, estimation methods based on isothermal micro-calorimetry are used to precisely analyze the thermal hazards and risks associated with chemicals and to develop an inherently safer design (ISD). Here, a thermal activity monitor III (TAM III) was used under various isothermal conditions to obtain the thermokinetics parameters of reaction mechanisms. Cumene hydroperoxide (CHP), a typical organic peroxide, is decomposed by the action of sulfuric acid to yield phenol and acetone in equimolar quantities. CHP undergoes multiple complex reactions when an autocatalytic reaction occurs under isothermal decomposition. The following reaction scheme was considered in this study: A + nB ⇌ (n + 1) B, A ⇌ B, B → C. This type of reaction generally accelerates as the reactant is consumed, and an autocatalytic substance is produced. As a result, an ISD is required for preparation, manufacturing, transportation, storage, and even elimination. The rich behavioral patterns of these autocatalytic reactions were revealed through multiple specific illustrations. [ABSTRACT FROM AUTHOR]

• Novel prediction approach for adiabatic runaway reaction. • Flammable components were detected in the pyrolysis gas production. • [BIM][NO3] thermal decomposition started at 125.0 °C. • [BIM][NO3] is unstable state at above 160.0 °C with drastic exothermic reaction. Ionic liquids (ILs) possess negligible vapor pressure, a low toxicity, a low melting point, and a vast liquid temperature range, rendering them as favorable candidates for new alternative solvents. However, some recent studies showed that ILs are flammable during thermal upsets. To explore the overall spontaneous combustion under upset conditions, we propose a safer method to investigate the IL's thermal hazards. Gas chromatography/mass spectrometry, Fourier transform infrared spectrometry, and flash point analysis results indicated that 1-butylimidazolium nitrate ([BIM][NO 3 ]) exhibits combustible characteristics and low thermal stability at high temperatures (over ca. 150.0 °C) during thermal decomposition. Meanwhile, differential scanning calorimetry, thermogravimetry, and vent sizing package 2 (VSP2) tests were used to describe the thermal properties of [BIM][NO 3 ]. The thermokinetic parameters were further acquired by using an isoconversional method. The results demonstrate that the suitable combination of anion and cation might yield energetic ILs. [ABSTRACT FROM AUTHOR]

The thermogravimetric techniques and differential thermal analysis have been employed in this work to analyze the macro-reactions mechanism of the silicon delay composition. Quantum chemical calculation has been performed to study the microscopic mechanism of the main reaction (Pb3O4 + Si) at the density functional theory BPW91/6−311++G(d, p) level of theory with the SDD implicit solvent model. Our results have shown that in the silicon delay composition, the strongest reaction exothermic peak is originated from the reaction between Pb3O4 cluster and Si. For the microscopic reaction process of Pb3O4 and Si containing two reaction pathways, we found that they proceeded in this manner, Pb3O4 + Si → SiO + 3PbO and SiO + Pb3O4 → SiO2 + 3PbO, with a total of four reaction channels. In addition, we have determined the reaction sites by making use of the charge distribution from natural bonding orbital analysis and the HOMO-LUMO gap of the reactants. [ABSTRACT FROM AUTHOR]

Azo compounds (azos) are vital basic initiators used in chemical plants that also possess thermally active properties. Azos may trigger serious accidents because of their intense exothermicity. We applied a specific method to characterize the reaction kinetics of azos using data from differential scanning calorimetry (DSC). Specifically, this method was used to analyse the thermal decomposition of 2,2-azobis(2-methylbutyronitrile) (AMBN). The exothermic peak temperature, exothermic final temperature, and heat of decomposition were determined. The data obtained from the experiments were utilized to predict the self-accelerating decomposition temperature, control temperature, and emergency temperature. Experiments conducted to explore the runaway phenomenon of AMBN during the overall decomposition process interfered with the thermal analysis studies. We utilized a process simulation model to mimic the decomposition of AMBN, ensuring that the simulation results were realistic and practical. The results are worthy of being applied to thermal analysis, for example, for application in proactive loss prevention. [ABSTRACT FROM AUTHOR]

Azo compounds, which readily show self-reactive traits, are extensively used in solution radical polymerization. If the phase of reaction is changed, such as in an endothermic process is weaker than in the exothermic decomposition process, it may cause serious fires and explosions. To ensure thermal safety of azo initiators in the process of creation, the commonly used oil-soluble azo initiators, 2,2′-azobis-(2-methylbutyronitrile), or so-called AMBN, are chosen to be explored. In this study, thermal decomposition characteristics under non-isothermal were obtained using differential scanning calorimetry. The composed data can be input into an equation such as isoconversional differential method with advanced thermal analysis technique to evaluate the cardinal thermal hazard for AMBN thermokinetic. [ABSTRACT FROM AUTHOR]

In this paper, we describe thermokinetic properties and decomposition characteristics of benzoyl peroxide, dicumyl peroxide, and lauroyl peroxide, which are widely used in the polymerization process as energy boosters. In the past, many accidents occurred that involved overpressure and runaway excursion of the process and thermal explosion. One reason for accidents is because of the peroxy group (-O-O-) of organic peroxides (OPs) due to its thermal instability and high sensitivity when exposing to heat. Apparent activation energy and pre-exponential factor were obtained during decomposition via non-isothermal well-recognized kinetic equation, fitting curve tests, and approximate solution to design safer reaction conditions when OPs are used as fuel. Moreover, the storage conditions were investigated for the simulation of thermal explosion in a 24-kg cubic box package and a 400-kg barrel reactor for commercial application. Experimental results established the novel features of solid explosion hazard of OPs. [ABSTRACT FROM AUTHOR]

The reaction of propylene with adsorbents such as BASF selexsorb CD and UOP of various sizes was studied. Adiabatic runaway tests were conducted on propylene mixed with various adsorbents to obtain knowledge on the thermal profile of each. Thermokinetic data were obtained from non-isothermal calorimetric study from the oligomerized reaction between propylene and various adsorbents. A detailed distribution of sorbent product from the adsorber has been analyzed for carbon product greater than 6 ( >C 6 ) using gas chromatography/mass spectrometry results. The test revealed oligomerization and carbonaceous deposit formation of the adsorbent products. The reason for over-temperature of the reactor wall can be anticipated from the agglomeration of carbonaceous deposit disrupting the normal flow of propylene stream causing channeling and lowering the carry-away of heat-accumulated. This approach of real conditions, along with the simulation of process design and operation using computational fluid dynamics (CFD) studies, can render safer process information for avoiding the occurrence of similar runaway explosion induced industrial disaster. [ABSTRACT FROM AUTHOR]

Numerous fires and explosions have occurred in chemical industries in Taiwan. In addition to considerable damage to equipment, such accidents cause environmental damage and even social turmoil, and they remind us of the importance of industrial process safety. Many of these accidents involve organic peroxides, which become extremely labile or unstable if they contact acids, bases, or other incompatibles. This study established thermokinetic and thermal safety parameters by differential scanning calorimetry and a thermal activity monitor III for cumene hydroperoxide (CHP) and its incompatibles. For the first time, this study reports the first real-time observation of the reaction of CHP with sulfuric acid by thermal imaging camera, which was used to determine the rate of heat evolution and recognize the degree of hazard present during thermal incidents. [ABSTRACT FROM AUTHOR]