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Imidazole ionic liquids (ILs) have broad application prospects in batteries and other fields. Researching the thermal decomposition features of ILs holds paramount importance for the application in battery electrolyte. 1-allyl-3-methylimidazole nitrate ionic liquid (IL) as a new functional IL, and its related thermal decomposition properties are unknown. In this paper, the thermal decomposition peculiarities of 1-allyl-3-methylimidazole nitrate IL were systematically analyzed by thermogravimetric analyzer, differential scanning calorimetry, and accelerating rate calorimeter techniques, and the relevant thermodynamic parameters and thermal decomposition models were derived. In addition, 1-allyl-3-methylimidazole nitrate IL possesses strong thermal runaway characteristics and the risk of thermal runaway is also evaluated. The main gaseous products formed by the pyrolysis of 1-allyl-3-methylimidazole nitrate IL was detected and analyzed by thermogravimetry-Fourier transform infrared spectroscopy and thermogravimetric-photoionization mass spectrometry techniques. The results showed that flammable gas, toxic gas, and asphyxiating gas are formed during the pyrolysis of 1-allyl-3-methylimidazole nitrate IL. This study lays a theoretical foundation for the safe application and the formulation of corresponding safety protection measures of 1-allyl-3-methylimidazole nitrate IL.

In the study, agricultural waste bagasse was used as a bio-based flame retardant for reducing the flammability of epoxy. Specifically, an interpenetrating network (IPN) was formed through a ring opening reaction between the hydroxyl functional group of bagasse and the epoxy group of triglycidyl isocyanurate (TGIC), forming Bagasse@TGIC. Next, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) was mixed with Bagasse@TGIC, inducing a reaction between the active hydrogen of DOPO and the epoxy group of TGIC, ultimately forming Bagasse@TGIC@DOPO with an IPN structure. Finally, the novel flame retardant was added to epoxy to create a composite. The integral procedural decomposition temperature (IPDT) of pure epoxy is 619 °C; after the introduction of the 30 wt% flame retardant, the IPDT of the resultant composite material increased to 799 °C, greatly increasing the thermal stability by 29%. After the addition of the Bagasse@TGIC@DOPO flame retardant, the limiting oxygen index increased from 21% for the pure epoxy to 29% for the composite, and the UL-94 rating improved from failing rating for the pure epoxy and V-0 rating for the composite. The Raman spectrum indicated that the addition of Bagasse@TGIC@DOPO IPN substantially increased the biochar yield during the burning process, increasing thermal stability. These results confirmed that the epoxy/Bagasse@TGIC@DOPO composite had substantial flame retarding effects.

Fish scales (FSs) are fishery wastes that can cause environmental pollution. This study aimed to solve this environmental problem. FSs were used as a flame retardant for polymer materials, making them valuable. Fish scales were combined with a commercial flame retardant, ammonium polyphosphate (APP), through synergistic effects to reduce the amount of commercial flame retardant. The use of FSs conforms to the concept of a circular economy and lowers costs by reducing the consumption of APP. Thermogravimetric analysis (TGA), integral procedural decomposition temperature (IPDT), pyrolysis kinetics, limiting oxygen index (LOI), the Underwriters Laboratories 94 (UL94) flammability test, scanning election microscopy, Raman spectroscopy, and energy-dispersive X-ray spectroscopy were used to determine the thermal properties, flame retardant properties, flame retardant mechanism, char morphology, and composition of the composites. The TGA results indicated that the addition of 40% flame retardant raised the char residue from 16.45 wt.% (pure EP) to 36.07 wt.%; IPDT from 685.6 °C (pure EP) to 1143.1°C; LOI from 21% (pure EP) to 30%; and UL94 classification from fail (pure EP) to V-0. These results suggest an increase in char residue, which indicates better protection of the polymer matrix material. The improvements in IPDT, LOI, and UL94 classification, which indicate greater thermal stability, lower flammability (from flammable to fireproof), and higher flammability rating (from fail to V-0), respectively, suggest that the composite material has favorable thermal properties and is less inflammable.

Polydimethylsiloxane with hydroxy groups was functionalized to form functionalized polydimethylsiloxane, which subsequently underwent an addition reaction with isophorone diisocyanate to form the prepolymer. Next, 3-aminopropyltriethoxysilane (APTS) reacted with 3-glycidoxypropyltrimethoxysilane (GPTS) to produce bridged polysilsesquioxanes, and sol-gel technology was employed to form hyperbranched polysiloxane nanoparticles with hydroxy groups, APTS-GPTS, which was used as the additive. The hyperbranched polysiloxane and the prepolymer containing NCO functional groups then underwent an addition reaction to produce the hybrid materials. Fourier-transform infrared spectroscopy and 29Si nuclear magnetic resonance were used to characterize the structure of the polyurethane hybrid. Regarding thermal stability, after the hyperbranched polysiloxane nanoparticles was introduced, the integral procedural decomposition temperature increased from 348 °C for polyurethane matrix to 859 °C for the hybrid material. The results reveal that the thermal stability of the hybrid material substantially increased by approximately 247%.

A new microencapsulated flame retardant containing melamine polyphosphate (MPP) and 4,4′-oxydianiline-formaldehyde (OF) resin as the core and shell materials, respectively, was synthesized by in situ polymerization. 29Si NMR was used to measure the condensation density of polyurethane containing silicon compound (Si-PU). The structures and properties of the microencapsulated melamine polyphosphate (OFMPP) were characterized using X-ray photoelectron spectroscopy, scanning electron microscopy and water solubility. Thermal behavior of the OFMPP was systematically analyzed through thermogravimetric analysis. Flame retardance tests such as the limiting oxygen index and UL-94 were employed to evaluate the effect of composition variation on the MPP and OFMPP in polyurethane composites. The results indicated that the microencapsulation of MPP with the OF resin improved hydrophobicity and that the flame retardance of the Si-PU/OFMPP composite (limiting oxygen index, LOI = 32%) was higher than that of the Si-PU/MPP composite (LOI = 27%) at the same additive loading (30 wt %).

Epoxy resin was often applied in fiber-reinforced composite materials, adhesives, and encapsulation materials. However, epoxy was easily flammable and limited its usage in certain applications. The study recycled and reused agricultural waste sugarcane bagasse to prepare a halogen-free bio-based intumescent flame retardant and then mixed with epoxy resin to prepare a composite containing polymer with improved thermal properties and flame retardancy of the materials. The work followed the concept of circular economy and sustainability. Bagasse-ammonium dihydrogen phosphate (ADP) flame retardant was added to an epoxy resin to prepare epoxy/bagasse-ADP composites, an effective flame-retarding composite material through hydrothermal method. Adding bagasse-ADP increased the thermal stability and flame retardancy of the composite materials compared with that of pure epoxy. For the material with 30 wt % added bagasse-ADP, the char yield was 32.3 wt%, which was 18.2 wt% higher than that of pure epoxy (14.1 wt%) through thermogravimetric analysis. In addition, the limiting oxygen index increased from 21% to 30%, and the UL-94 classification improved from "Fail" to "V-0." This performance was attributed to the nitrogen, phosphorus, and silicon content of the flame retardant. [ABSTRACT FROM AUTHOR]

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-methyi 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 TMRad 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]

1,3-Dimethylimidazolium nitrate ([Mmim]NO3), an ionic liquid, is a versatile and novel solvent for the petrochemical industry. Nevertheless, under high temperature conditions or thermal upset scenarios, [Mmim]NO3 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]NO3 by simultaneous thermogravimetric analyzer and high pressure differential scanning calorimetry. Isothermal experiments indicated that [Mmim]NO3 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]NO3, 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 (T0.1/10h) was defined to assess the long-term thermal stability, which can be used as the maximum operating temperature of [Mmim]NO3. The results of this study may provide relevant processes for safer control based on the thermal hazard assessment of [Mmim]NO3. [ABSTRACT FROM AUTHOR]

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][NO3]) 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][NO3]. 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]

This study investigated the role played by green thermal analysis technology in promoting the use of resources, preventing pollution, reducing energy consumption and protecting the environment. The chemical tert-butyl peroxybenzoate (TBPB) has been widely employed in the petrifaction industries as an initiator of polymerization formation agent. This study established the thermokinetic parameters and thermal explosion hazard for a reactor containing TBPB via differential scanning calorimetry (DSC). To simulate thermokinetic parameters, a 5-ton barrel reactor of liquid thermal explosion model was created in this study. The approach was to develop a precise and effective procedure on thermal decomposition, runaway, and thermal hazard properties, such as activation energy ( E), control temperature ( CT), critical temperature ( TCR), emergency temperature ( ET), heat of decomposition ( ∆H), self-accelerating decomposition temperature ( SADT), time to conversion limit ( TCL), total energy release ( TER), time to maximum rate under isothermal condition ( TMR), etc. for a reactor containing TBPB. Experimental results established the features of thermal decomposition and huge size explosion hazard of TBPB that could be executed as a reduction of energy potential and storage conditions in view of loss prevention. [ABSTRACT FROM AUTHOR]

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]