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Micronsized spherical CL-20/RDX composites with uniform size were prepared by an electrospray method. After preparation, the morphology, crystal structure, thermal decomposition property, explosion performance and mechanical sensitivity were characterized. Different structures existed in the CL-20/RDX composites with different molar ratios. The CR11e composites had the lowest apparent activation energy and the lowest critical temperature of thermal explosion. The explosion pressure and mechanical sensitivity of CL-20/RDX composites were lower than that of raw CL-20 and decreased with increasing RDX content. [ABSTRACT FROM AUTHOR]

Phthalonitrile monomer containing oxazine ring (BPS‐Ph) was synthesized using bisphenol‐S, aniline, paraformaldehyde, and 4‐nitrophthalonitrile via a two‐step method. The differential scanning calorimetry (DSC) data of the curing process of BPS‐Ph monomer indicates that the peak polymerization temperature of the cyan group is about 250°C and that confirms the promoting effect of oxazine ring on the curing reaction of phthalonitrile. The rheological data of E51/DDS containing BPS‐Ph indicates that the BPS‐Ph monomer also has promoting effect on the curing process. The activation energy was studied via the iso‐conversional method principle. The activation energy corresponding to the E51/DDS crosslinking reaction is 75.79 and 60.54 kJ mol−1, respectively, for pure E51/DDS and E51/DDS/BPS‐Ph. Moreover, the activation energy of the crosslinking of phthalhydrazine is 74.1 kJ mol−1 which is rather lower than that in pure BPS‐Ph, and that implies the synergistically catalytic effect of the oxazine ring and the amine. The addition of BPS‐Ph monomer significantly improves the thermal behaviors of the thermoset. The char yield in N2 atmosphere increased from 15.6% to 53.9% when adding 30% BPS‐Ph to the E51/DDS. Moreover, the peak weight loss temperature decreased from 407 to 385°C. The phase separation size of poly‐BPS‐Ph in E51/DDS is about tens to hundreds nanometers according to the atomic force microscopy (AFM) phase diagram. It is indicated that incorporation of phthalonitrile monomer containing oxazine ring into epoxy/amine system is an applicable and effective way to promote the thermal behavior of the thermoset. [ABSTRACT FROM AUTHOR]

A novel epoxy resin, DPHP, was synthesized from diphenolic acid, which contains biobased levulinic acid, with triethylphosphite, to improve the flame retardancy of bisphenol‐A diglycidyl ether (BADGE) epoxy. Curing experiments were conducted using isophorone diamine as a curing agent for BADGE and DPHP mixtures. Variations in cure kinetics, mechanical properties, and flame retardancy were evaluated across different DPHP contents. The introduction of phosphorus functional groups into DPHP affected the polarization of epoxide CO bonds, resulting in reduced apparent activation energy for epoxy curing reactions. However, the higher epoxy equivalent weight of DPHP compared with that of BADGE led to a decrease in the tensile strength and the glass transition temperature of the cured material with increasing DPHP content. A significant increase in char yield for combustion of the epoxy blend was observed, ranging from 8.3% at 0 wt% DPHP to 20.1% at 50 wt% DPHP. Additionally, cone calorimeter measurements showed significant reductions in heat release rate and total heat release, leading to a decrease in fire spread from 1.07 MJm−2 s−1 at 0 wt% DPHP to 0.43 MJm−2 s−1 at 50 wt% DPHP. These results show that the flame retardancy of the cured material improved significantly as the DPHP content increased. [ABSTRACT FROM AUTHOR]

The current study investigates the impact of interfacial interactions between the silicone rubber base polymer matrix and the hexagonal boron nitride (hBN) nanofiller, incorporated at different weight percentages, on electrical, thermal, and mechanical properties. The adhesion of filler to the polymer is examined through swelling tests and Kraus plots and the elastic modulus calculated has a good agreement with the experimental data. The addition of 3 wt% of BN nanofiller with silicone rubber led to a 25.4 % increment in surface discharge inception voltage (SDIV). The Thermogravimetric analysis (TGA) shows that the BN filler included samples have high degradation temperature and thermal activation energy. The introduction of filler into the base polymer matrix significantly enhances mechanical properties, specifically tensile strength, tensile modulus, and percentage elongation at break. [ABSTRACT FROM AUTHOR]

Dy 2 O 3 –Sm 2 O 3 co-doped transparent glass ceramics (GCs) containing NaBi(WO 4) 2 crystalline phase were prepared by melt-curing-crystallization method. The optimal heat treatment condition is 580 °C/2 h. The optimum incorporation concentration of Dy 2 O 3 is 0.4%, exceeding which a quenching phenomenon dominated by quadrupole-quadrupole interactions emerges. Meanwhile, when the concentration of Dy 2 O 3 was fixed, the chromaticity coordinate of the sample moved the cool white light region to the warm white light region as the concentration of Sm 2 O 3 increased. The temperature-dependent emission spectra of the 0.4% Dy 2 O 3 -0.7% Sm 2 O 3 co-doped GC samples show that emission intensity at 575 nm at 185 °C still reaches 80% of the room temperature. The thermal quenching activation energy was 0.1537 eV and the activation energy after the addition of Mo6+ was 0.1957 eV. This study indicates that Dy 2 O 3 –Sm 2 O 3 co-doped GCs containing NaBi(WO 4) 2 crystalline phase can achieve light-color tunable emission, which is potentially valuable for solid-state color rendering and illumination applications. [ABSTRACT FROM AUTHOR]

In order to design and optimize thermochemical systems for the production of bioenergy understanding the energy capacity of the pistachio shell and its kinetics of degradation is crucial. The Thermogravimetric analysis at different heating rates of biomass was studied along with thermodynamic study, primary characterizations like the composition of biomass, heating value and a reaction mechanism-assisted kinetic model. Nitrogen gas flow rate is used for thermogravimetric analysis (TGA), which is performed at 10, 15, 20 and 30 ℃/min different heating rates from room temperature to 900 ℃. The output also shows that maximal degradation took place between 180 and 430 °C. The various iso-conversional models, such as Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), Starink and Friedman, are used to calculate kinetic and thermodynamic parameters, which give the average value of activation energy as 172.29, 170.47, 169.79, and 193.25 kJ/mol. The average values of Gibbs free energy for the FWO, KAS, Starink and Friedman techniques were found to be 176.49, 1176.54, 176.29, and 175.78 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

In this work, an acid invertase isolated from Lathyrus aphaca seedlings is purified, and its thermal properties are investigated. Acid invertase was purified through salt fractionation, CM-cellulose, and Ultrogel ACA-44 chromatography. Using SDS-PAGE, the consistency of the isolated enzyme was verified. The enzyme weighs 29 kDa at the molecular level. Acid invertase functions best at a pH of 3.0 and a temperature of 45 °C. Activation energy of 29.5 kJ mol−1 and K m and V max values of 0.5 mM and 119.7 µmol. min−1. mg−1 of protein was found for the isolated enzyme. It was shown that the mercaptide-forming agent p -chloromercuribenzoic acid (PCMB; 0.5 mM) and the enzyme's activity were both modestly increased by Ca2+, Mn2+, and Mg2+ ions but inhibited by Hg2+, Cd2+, and Pb2+ ions. At elevated temperatures, the invertase exhibited an increase in thermostability due to an increase in activation entropies (∆Sº) and a decrease in activation enthalpies (∆Hº). The interactions between 4 M urea and α-chymotrypsin were tetraphasic, causing periodic increases and decreases in invertase activity. It also suggests a potential explanation for acid-invertase thermal inactivation at high temperatures. This enzyme might be a catabolite-resistant invertase to produce high-gravity ethanol or fructose syrup. [Display omitted] • Acid invertase was purified from Lathyrus aphaca seedlings with molecular weight 29 kDa. • Acid invertase free in a solution of 5% (w/v) sucrose, pH 3.0, is stable up to 50 °C for a period of 4 h. • The K m and V max values for acid invertase was 0.5 mM and 119.7 µmol. min-1.mg−1 of protein. • The acid invertase is more stable and their energy of deactivation are 107 kJ/mol (25 kcal/mol), respectively. • The effects of α-chymotrypsin and 4 M urea were tetraphasic with periodic gain and loss of enzyme activity. [ABSTRACT FROM AUTHOR]

To study the effect of internal particle size on the microstructure properties and thermal decomposition characteristics of site mixed emulsion explosive at different altitudes. Site mixed emulsion explosive was prepared with different shear rate. The particle size, viscosity, sensitized bubbles, detonation velocity and peak pressure of the emulsion explosive were tested after stored at different simulated altitudes. The thermal decomposition characteristics of emulsion matrix prepared at three different rotational speeds were measured by thermogravimetric analyzer and kinetic analysis was performed by non-isothermal model Kissinger–Akah–Sunose (KAS) method. The results show that with the increase in altitude, the internal phase size showed a trend of first increasing and then decreasing, and the number of sensitized bubbles within the emulsion explosive decreases. At an altitude of 0 m, the detonation velocity and peak overpressure of the emulsion explosive prepared by 1600 r min−1 increased 4.78% and 29.09%, respectively compared with 1200 r min−1, and at an altitude of 4500 m, the detonation velocity increased 11.87%, the peak overpressure increased 43.98%. The thermal decomposition activation energy of the emulsion matrix at 1600 r min−1 increased 13.14% compared to 1200 r min−1. It shows that in the production of site mixed emulsion explosive at high altitude, reducing the particle size of the internal phase of emulsion explosives in a certain range can effectively improve the performance of emulsion explosives. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the thermomechanical and antioxidant properties of an active film composed of carrageenan and cellulose nanofibers incorporating (0.1%v/v–0.5%v/v) eugenol (Eu), intended for active packaging applications. The mechanical, physical, morphology, and thermal properties of the active film were extensively characterized, and the antioxidant activity was monitored over a 34‐day‐storage period. Broido's model was employed to assess the thermomechanical properties and activation energy of the films towards the Eu structure in carrageenan and cellulose nanofiber film. The findings revealed that the addition of Eu had a negative impact on the activation energy of the film's decomposition while positively affecting the release of antioxidants during storage. The film containing 0.4% Eu demonstrated optimal physical and mechanical characteristics, including a tensile strength of 38.08 ± 2.06 MPa and elongation at break of 21.95% ± 9.02%. Furthermore, the SGC‐0.4% (SGC stand for Semi refined carragenan + Glycerol + Cellulose nanofiber) Eu film exhibited a higher activation energy (365.82 kJ/mol), suggesting enhanced stability and durability compared with other films. The film with 0.4% Eu content showed the highest release rate of polyphenols (614.9290 mg gallic acid/L sample) up to 28 days of storage. Additionally, it exhibited a 58% efficiency of radical scavenging activity. Overall, these results highlight the potential of the SGC‐0.4% Eu film as a biodegradable packaging solution that offers prolonged food shelf life. [ABSTRACT FROM AUTHOR]

This paper investigates the synthesis, crystal structure, thermal properties, and energetic performance of two 1D coordination polymers (CPs). The CPs, namely, [Zn(atrz)(DNBA)2(H2O)2]n (1) and [Cd(atrz)(DNBA)2(H2O)2]n (2), were designed and synthesized based on the nitrogen-rich ligand 4,4′-azobis-1,2,4-triazole (atrz) and 3,5-dinitrobenzoic acid (HDNBA) via a mixed ligand strategy using a simple and environment-friendly method. The CPs were characterized by various spectroscopic and analytical techniques along with single-crystal X-ray diffraction (SCXRD). SCXRD analysis reveals a distorted octahedral geometry around the metal ions (Zn/Cd), leading to the formation of a 1D coordination polymer while constructing a 2D structural framework through intermolecular hydrogen bonding. Both the CPs exhibit similar thermal stability but considerably differ in their heat of formation values (1 = −894.43, 2 = 1635.93 kJ mol−1). CP 2 has higher detonation velocity (7.24 km s−1) and pressure (23.67 GPa) compared to 1 (detonation velocity: 6.28 km s−1, detonation pressure: 17.57 GPa) owing to its higher heat of formation and density. Both the CPs exhibit ideal insensitivity to friction and impact stimuli, ensuring their safety during transportation and processing. The value of average activation energy obtained from isoconversion ASTM E698 for 1 and 2 was reported to be 143.8 and 168.0 kJ mol−1, respectively. This study explores the development of energetic CPs through the mixed ligand strategy based on the atrz ligand and incorporating HDNBA as the co-ligand to reduce the sensitivity while maintaining the comparable energetic performance of previously reported atrz-based complexes. This paper also highlights the potential use of CPs as explosives by demonstrating higher energetic performance. [ABSTRACT FROM AUTHOR]

Biological methods present a sustainable approach for treating various waste polymers due to green, low-cost, mild condition and simple operation. This study, a novel biological method to process nitrocellulose (NC) to obtain NC with low nitrogen via nitrate ester removal using fungal Chaetomium elatum is proposed. The N% of NC continuously declined during the course of six days, from 13.06% to 11.71%, and the intensity of its energetic groups (O-NO2, -NO2) also weakened. An examination of the thermal properties of NC revealed that the weight-loss ratio decreased after biotreatment from 86.33% (untreated NC) to 66.20% (treated NC).Furthermore, the kinetic parameters of the thermal decomposition reaction with DSC were calculated and the activation energy (Ea) of biotreated NC was higher than that of the original, indicating the thermal stability was enhanced. Hence, this structure exploration and thermal analysis provide new methods for further investigating the mechanism of the biological denitrification process and assessing the safety of biotreated NC. [ABSTRACT FROM AUTHOR]

To investigate the effect of composite energetic binders on the performance of DAAF at ambient as well as elevated temperatures, DAAF solid microspheres with uniform particle size were prepared using droplet microfluidics. The morphology, particle size distribution, structure, thermal properties and mechanical susceptibility of the microspheres were characterized and analyzed. The results show that the use of composite binder can effectively improve the thermal stability of DAAF, and the activation energy is increased from 168.87 to 218.53 kJ ⋅ mol−1. The crystal shape is not changed after cladding, and the impact sensitivity value is improved by 5 J over the submicron DAAF. Composite energetic binder DAAF microspheres and submicron DAAF were selected for experiments under high temperature environment. The results showed that at high temperatures, when the mass loss was more than 16 %, the submicron DAAF was better than the DAAF microspheres in terms of storage time. [ABSTRACT FROM AUTHOR]

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This study explores the impact of different levels of halloysite nanotubes (HNT) and d-isomer on the non-isothermal crystallization behavior of the polylactic acid (PLA). The processing conditions, thermal flow, molecular orientation and the presence of nanofillers can affect the crystallinity and properties of PLA. In this work, PLA-based nanocomposite filaments were produced and their crystallization kinetics was studied. The data obtained through experiments, using differential scanning calorimetry at various cooling rates, were analyzed employing the Jeziorny and Mo models. And the activation energy of crystallization was determined by the Friedman method. The results showed that the growth of PLA crystals is three-dimensional, the HNT can accelerate the crystallization process, and crystallization occurs at higher temperatures in the presence of flow. The activation energy increased with addiction of more HNT in the nanocomposite. The study also found that the d-isomer has a more significant influence on the crystallization of PLA than HNT, which can inhibit crystal formation in some cases. These findings provide insights into the factors that can influence the properties of PLA nanocomposites and how they can be optimized. [ABSTRACT FROM AUTHOR]

SnxSb20Se80−x bulk glasses were prepared using the well-known melt quenching technique, where x was taken as 7.5 at.%, 9.5 at.%, 11.5 at.% and 13 at.%. X-ray diffraction (XRD) and differential scanning calorimetery (DSC) were used to monitor the crystallinity and transition temperatures, respectively. XRD examinations showed that the 7.5 at.% and 9.5 at.% compositions were purely amorphous, while the other two compositions exhibited a crystalline structure. DSC thermograms demonstrated that 7.5 at.% and 9.5 at.% alloys had a single crystallization peak, whereas for the 11.5 at.% and 13 at.% alloys, two exothermic peaks and three peaks appeared. The glass stability and kinetics of amorphization and crystallization were studied using different approaches. The correlation between topological constraints and the dimensionality of the growth was established. [ABSTRACT FROM AUTHOR]

The influences of ethylene-based elastomer (EE) and the compatibilizer agent ethylene-butyl acrylate-glycidyl methacrylate (EBAGMA) on the thermal degradation of PLA/EE blends were evaluated by the thermal degradation kinetics and thermodynamic parameters using thermogravimetry. The presence of EE and EBAGMA synergistically improved the PLA thermal stability. The temperature of 10% of mass loss (T10%) of PLA was around 365 °C, while in the compatibilized PLA/EE blend, this property increased to 370 °C. The PLA average activation energy ( E a ¯ ) reduced in the PLA/EE blend (from 96 kJ/mol to 78 kJ/mol), while the presence of EBAGMA in the PLA/EE blend increased the E a ¯ due to a better blend compatibilization. The solid-state thermal degradation of the PLA and PLA/EE blends was classified as a D-type degradation mechanism. In general, the addition of EE increased the thermodynamic parameters when compared to PLA and the compatibilized blend due to the increase in the collision rate between the components over the thermal decomposition. [ABSTRACT FROM AUTHOR]

In this work, post-consumer poly(ethylene terephthalate) (PET) bottles were gathered, separated from other materials, and re-extruded. In order to evaluate the effect of re-extrusion on the structure of PET, Fourier transform infrared spectroscopy was utilised. No significant effect of the re-extrusion process on the structure of the PET sample was noticed. Obtained samples were also characterised by differential scanning calorimetry (DSC) in order to determine characteristic thermal transitions of PET. DSC results indicated the influence of re-extrusion; extruded PET started to melt at lower temperatures, and the crystallisation of re-extruded PET took place at significantly higher temperatures in comparison to PET. Likewise, thermogravimetric analysis (TG) was used to evaluate the effect of re-extrusion process on the thermal stability of samples. TG analysis revealed that the re-extrusion process had no effect on the thermal stability of the investigated PET samples. Finally, the activation energy of thermal degradation of the investigated samples was calculated using iso-conversional Flynn-Wall-Ozawa and Friedman method. Consequently, higher activation energies were noticed for the re-extruded PET sample in comparison to the PET bottle sample, which is a good argument in support of PET bottle recycling.

This study examines the viability of functionalized, nano, and active zinc oxide (ZnO) as an alternative activator in styrene butadiene rubber–natural rubber (SBR–NR) blends filled with carbon black. Concerns about the environmental impact and toxicity of Zn leaching into aquatic organisms necessitate reducing the amount of ZnO in rubber compounding. The mechanical properties, crosslink density, and thermal and morphological qualities of the SBR/NR blends made with these ZnO (F2BB, N2BB, and A2BB) were studied and compared to conventional ZnO loaded blend (C5BB). Thermal stability was evaluated using thermogravimetric analysis and temperature scanning stress relaxation. A2BB showed the highest thermal stability, while F2BB exhibited a 35% increase in tensile strength and a 28% increase in elongation at break due to polysulfide linkages. N2BB and A2BB increased tensile strength by 28 and 16% compared to C5BB. Cytotoxicity of various ZnO concentrations on HT‐22 hippocampal cells was investigated, and active and nano ZnO were found to be less toxic. Using active and nano ZnO can improve the mechanical and thermal properties of the blend while reducing environmental toxicity, allowing for a 60% reduction in ZnO concentration in rubber compounds and resulting in cost savings and a sustainable alternative to conventional ZnO. [ABSTRACT FROM AUTHOR]

This study aims to investigate the thermal properties of the phase transformation that may occur with the effect of temperature in Cu-14.70wt.%Al-4.72wt.%Ni shape memory alloy. The sample was annealed at 1203 K for 30 min in an argon atmosphere and then cooled rapidly in salt-ice water. By using Differential Scanning Calorimetry (DSC), the martensitic phase transformation parameters of the sample were found. The activation energy required for these transformations was calculated using the Kissinger, Augis-Bennett, and Takhor methods. Thermogravimetric Analysis (TGA) measurements investigated the mass changes that may occur with the effect of temperature. Surface morphology was analyzed using an optical micrograph.

To improve the thermal properties of thermite safely and stably, electrostatic spraying was used to prepare the Al/MoO3 thermite. The Al/MoO3 thermites were detected and characterized by scanning electron microscopy (SEM) and X‐ray diffraction (XRD), and thermal decomposition experiments were carried out by differential scanning calorimetry (DSC). The heat release of the Al/MoO3 thermite prepared by the electrostatic spray (1044 J g−1) is significantly higher than that of the thermite prepared by the ultrasonic (692 J g−1), which is due to more uniform dispersion between Al and MoO3. The initial reaction temperature and activation energy (Ea) of the former keep it steady. Electrostatic spray ensures the safety and stability of the Al/MoO3 thermite. This study provides a new idea for safely and stably improving the thermal properties of thermite by enhancing surface homogenization, which is of great significance for practical applications. [ABSTRACT FROM AUTHOR]

The thermal decomposition of Hexanitrohexaazaisowurtzitane CL‐20/HMX‐ammonium formate functionalized graphene oxide (Am‐GO) composites was studied using an isothermal decomposition dynamics research instrument to explore the effects of Am‐GO on the stability of CL‐20/HMX co‐crystal. The gas pressure‐time curve generated by thermal decomposition reaches the decomposition inflection point at a decomposition degree of 85 %. Compared with CL‐20/HMX co‐crystal, the decomposition extent corresponding to the inflection point of the thermal decomposition curve of the composites increases. The activation energies of the composites before and after the inflection point of the pressure‐time curve were 161.3 kJ/mol and 171.0 kJ/mol, respectively. The residual substances produced by the thermal decomposition of the composites were characterized by HPLC and FTIR. Results showed that CL‐20 and HMX were decomposed before the inflection point of the decomposition pressure‐time curve. However, the decomposition of CL‐20 was completed before the inflection point, whereas that of HMX ran through the thermal decomposition process. The calculation results of thermal decomposition kinetics show that the addition of coating material increases the activation energy of co‐crystal and stabilizes CL‐20/HMX co‐crystal. [ABSTRACT FROM AUTHOR]

We investigate the electrical and thermal conduction properties of low- (ON) and high-resistance (OFF) states in Pt/NiOx/Pt based unipolar ReRAM devices during cooling and warming cycles between 300 and 180 K. The conduction electron-trap activation energy was found to decrease upon warming. Although thermal cycling did not significantly affect the average resistance-temperature coefficient of the Pt diffused conductive filaments in the system, the ON-state resistance fluctuations increase at high temperatures, indicating that ambient temperature significantly affects the sizes of the formed filaments. The mechanism behind these thermally activated changes is discussed. [ABSTRACT FROM AUTHOR]

The composite powders of nanoscale aluminum (n-Al) and iron fluoride (FeF3) were prepared by an ultrasonic mixing method. The microscopic morphology was examined by scanning electron microscopy, the crystalline phase structure was analyzed by X-ray diffractometer, and extensive thermal analysis of the single components and composites was carried out, focusing on the thermal reaction properties of n-Al/FeF3. The reaction process and pre-ignition reaction of the complexes were investigated by characterizing the reaction products of n-Al/FeF3 and Al2O3/FeF3 at certain temperatures. Finally, the apparent activation energy of the thermite reaction of n-Al/FeF3 was determined using the Ozawa method, the Flynn method, and the Starink method. Under an Ar environment, n-Al/FeF3 could react at a lower temperature (613.8 ℃) and give off more heat (1097.0 J g−1) compared with n-Al/Fe2O3. In the air environment, n-Al/FeF3 also showed a lower reaction temperature (509.7 ℃). N-Al could be totally oxidized at a lower temperature with a higher degree of reaction, although the reaction heat release (1477.6 J g−1) was lower than that of n-Al/Fe2O3 (2692.5 J g−1). A pre-ignition reaction occurred before the main reaction of n-Al/FeF3, but no evident exothermic peaks were found in the thermal analysis. The activation energies of exothermic peaks 1 and 2 for n-Al/FeF3 were 113.79 kJ mol−1 and 185.45 kJ mol−1, respectively, slightly higher than those of n-Al/Fe2O3. The study results reported in this work provide a certain reference for the in-depth research and application of the n-Al/fluoride thermite system, as well as fresh ideas for the development of novel nanothermite materials. [ABSTRACT FROM AUTHOR]

Ammonium nitrate (AN) is a high energetic material that is being explored as a more eco-friendly replacement for ammonium perchlorate (AP) in composite solid propellants. The thermal decomposition properties of AN can greatly influence the thermal and combustion performance of high energetic formulations. To improve the thermal decomposition of AN, nanocrystalline (17.5 nm) cobalt–copper–nickel ferrite (CoCuNiFe2O4) was incorporated into AN using physical mixing. The thermal decompositions of pristine AN and AN + CoCuNiFe2O4 were compared to evaluate the better-performing energetic formulation. Simultaneous thermal analysis (thermogravimetry (TG)-differential scanning calorimetry (DSC)) was used to obtain information about the thermal decomposition properties of the AN + CoCuNiFe2O4 formulation. Decomposition of AN + CoCuNiFe2O4 occurred at a 10 °C lower temperature than that of pristine AN. Non-isothermal isoconversion methods were used to calculate the activation energy and pre-exponential factor of the thermal decomposition process using simultaneous thermal analysis data at 5, 10, and 15 °C min−1 heating rates. The non-isothermal isoconversion analysis suggested a lower activation energy barrier of AN + CoCuNiFe2O4 (4% decrement than pure AN) with a decreased pre-exponential factor. The thermo-kinetic investigations suggested that AN + CoCuNiFe2O4 can be used as a potential energetic ingredient in solid composite formulations for better thermal performance. [ABSTRACT FROM AUTHOR]

Through isoconversional analysis of differential scanning calorimetry data, thermally induced processes of glass transition and crystallization in Cux(As2Se3)100-x chalcogenide glasses (x =1, 5, 10, and 15 at.%) were investigated. The characteristic values of activation energy and its changes during the processes were calculated using the advanced isoconversional method developed by S. Vyazovkin as well as isoconversional forms of Kissinger and Moynihan relations. The results showed the variation of the activation energy with the extent of conversion. The activation energy values are slightly changing with the increase of Cu content from 1 to 5 at.%, while more significant changes are detected after a further increase of Cu content up to 15 at.%. The crystallization processes of As2Se3 in composition with 1 at.% of Cu and CuAsSe2 and Cu3AsSe4 in composition with 10 at.% of Cu were analyzed. Isoconversional analysis showed that crystallization is a complex process and that the apparent activation energy of crystallization of As2Se3 and CuAsSe2 structural units decreases with the extent of conversion increase. [ABSTRACT FROM AUTHOR]

In this work, post-consumer poly(ethylene terephthalate) (PET) bottles were gathered, separated from other materials, and re-extruded. In order to evaluate the effect of re-extrusion on the structure of PET, Fourier transform infrared spectroscopy was utilised. No significant effect of the re-extrusion process on the structure of the PET sample was noticed. Obtained samples were also characterised by differential scanning calorimetry (DSC) in order to determine characteristic thermal transitions of PET. DSC results indicated the influence of re-extrusion; extruded PET started to melt at lower temperatures, and the crystallisation of re-extruded PET took place at significantly higher temperatures in comparison to PET. Likewise, thermogravimetric analysis (TG) was used to evaluate the effect of re-extrusion process on the thermal stability of samples. TG analysis revealed that the re-extrusion process had no effect on the thermal stability of the investigated PET samples. Finally, the activation energy of thermal degradation of the investigated samples was calculated using iso-conversional Flynn-Wall-Ozawa and Friedman method. Consequently, higher activation energies were noticed for the re-extruded PET sample in comparison to the PET bottle sample, which is a good argument in support of PET bottle recycling. [ABSTRACT FROM AUTHOR]

Barely explored in the prior literature, ruby chocolate was investigated in this study to explore its thermal properties. The fatty acid composition of ruby chocolate (RC) fat was determined using gas chromatography. Differential scanning calorimetry (DSC) was successfully used to determine the melting behavior and polymorphic forms of the cocoa fat and milk fat present in the RC. The oxidative stability of the fat extracted from the RC was studied with the use of pressurized differential scanning calorimetry (PDSC). The thermal behavior of the chocolate and the fat were investigated using thermogravimetry (TGA). The thermal profile and characteristics of the RC showed how the parameters compared with those of dark and milk chocolate. The melting temperature of the RC obtained by DSC was more similar to that of milk chocolate than to that of dark chocolate. Regression analysis of the PDSC data for the fat extracted from the RC was characterized by very high correlation coefficients (>0.99). It was noticed there was no statistically significant difference between the values of the activation energy (Ea) of the oxidation process for the fat extracted from the RC, obtained by the means of maximum temperature (dynamic mode) and maximum induction time (isothermal mode). [ABSTRACT FROM AUTHOR]

Natural fiber composites are gaining more attention in automobile and aerospace industries due to its light weight with better performance. However, its performance is affected by the critical environment such as high temperature. Hence, analyzing the thermal stability of materials is paramount important. In this investigation, natural fiber-based composite was fabricated using Indian almond (I) and Veli karuvelam fibers (V) and its thermal stability was analyzed. Totally, five composites were fabricated viz. I:V(0:1) – 60 wt% epoxy and 40 wt% Veli karuvelam, I:V(1:3) – 60 wt% epoxy, 10 wt% Indian almond, and 30 wt% Veli karuvelam, I:V(1:1) – 60 wt% epoxy, 20 wt% Indian almond, and 20 wt% Veli karuvelam, I:V(3:1) – 60 wt% epoxy, 30 wt% Indian almond, and 10 wt% Veli karuvelam, and I:V(1:0) – 60 wt% epoxy and 40 wt% Indian almond. Thermogravimetric analysis was made, and the best composite was selected, which was further involved into thermal analysis, and the activation energies were determined by KAS and FWO kinetic models. Results showed that the I:V(0:1) composite showed the superior thermal stability compared to all other composites, and an onset degradation temperature of 387.64°C was observed. Further, the average activation energies determined by FWO and KAS models were showed as 51.73 and 42.19 kJ/mol, respectively, for I:V(0:1) composite. Hence, this investigation concludes that the I:V(0:1) composite could be a better candidate in the automobile and aviation fields to adopt the thermal environment.

In this study, B50/70 penetration grade original bitumen was modified by adding nanoclay at 2%, 4%, 6%, and 8% ratios. Subsequently, penetration, softening point, and rotational viscometer tests were performed on non-aged and short-term aged samples. The effect of nanoclay addition to bitumen on the susceptibility of bitumen to high temperature was evaluated with different equations. Since the central focus of the study is to assess the temperature susceptibility and the reaction to thermal changes of the nanoclay added bitumen, a differential scanning calorimetry experiment was performed on the samples, and the temperature susceptibility criteria that are obtained from the binder experiment results such as penetration index, viscosity–temperature susceptibility, and pen-vis number were calculated. In addition, the temperature range in the rotational viscometer experiment was kept broad, and measurements were made at 10 °C increments. By fitting these measurements into the Arrhenius equation, activation energies of original and modified bitumen were obtained. The results revealed that adding nanoclay improved the temperature susceptibility, high-temperature performance, and the resistance properties to aging of the binders. [ABSTRACT FROM AUTHOR]

In this work, effects of the silicone resins on copolymerization of the acrylated epoxidized soybean oil were investigated. Rheological characteristics, curing behaviors, and thermal properties of acrylate epoxy soybean oil prepolymer (AP), silicone prepolymer (SP), and their hybrids (AP/SP) were studied in detail. Spots in a snowflake pattern were observed on the fracture section surface of cured AP/SP hybrid resins by SEM. According to the change of polymer groups revealed by Fourier transform infrared, a possible reaction between AP and SP was proposed. The curing mechanism of AP/SP hybrids was researched, which was suggested to be an autocatalytic curing process. Furthermore, the degree of cure, the activation energy (Eα) and the reaction frequency factor (A) of the curing reaction were estimated. It was found that the cure kinetic of AP/SP hybrid resins could be well‐described by a Sesthk‐Bergglen model with the numerical optimization based on the Kissinger method and the Malek approach. The experimental results show that the mass retention rates of AP/SP hybrid resins were significantly increased after curing, indicating that the thermal stability of AP was enhanced with the addition of SP. [ABSTRACT FROM AUTHOR]

The inherent source of gelatin used for commercial hard capsules causes a surging demand for vegetarian capsules. In this work, carrageenan is utilized in preparing hard capsules to meet consumer preferences. Hydroxypropyl methylcellulose (HPMC) was incorporated as a reinforcing agent to improve the low mechanical properties of hard capsules made of carrageenan. The HPMC concentration was manipulated from 0.2 to 1.0 w/v% in the carrageenan matrix. The increasing concentration of HPMC exerts significant effects on the tensile strength and elongation at break, with an improvement of 59.1% and 46.9%, respectively, at the optimized HPMC concentration of 0.8 w/v%. The loop strength of the capsule is also increased by 56.4% with decreasing moisture content. The downfield movement from around 3.20 ppm of the carrageenan proton to 3.33 ppm in the proton nuclear magnetic resonanance (1H‐NMR) spectrum suggests the formation of intermolecular hydrogen bonding between carrageenan and HPMC, which correlates to the results of Fourier‐transform infrared spectroscopy (FTIR) and zeta potential. The glass transition temperature of the film was increased from 37.8 to 65.3°C, showing an upgrade in thermal stability. The film possesses a major mass loss with an activation energy of 64.7 kJ/mol with an increment of 43.4% compared to the control carrageenan. These findings support the conclusion that HPMC enhanced the mechanical properties and thermal stability of the carrageenan film, and the comprehensive analysis of the molecular interaction and decomposition kinetics subsequently may expand the application fields of the carrageenan‐HPMC hard capsule as an alternative to gelatin in the future. [ABSTRACT FROM AUTHOR]

The main objective of this work is to investigate how the addition of the magnesium hydroxide particles affects thermal properties and consequently the mechanism of thermal degradation of polyethylene oxide. With this aim, polyethylene oxide composites, with different composition of magnesium hydroxide particles derived from the sea bittern residual, were prepared via hot melt extrusion. Non-isothermal thermogravimetry in nitrogen atmosphere was utilized, and on gained data, the kinetic analysis was performed. Activation energy, pre-exponential factor and kinetic model were calculated and compared. TG analysis revealed that thermal degradation of composites starts at lower temperatures, which could be an indication of magnesium hydroxide destabilizing effect on polyethylene oxide. Kinetic analysis showed that all composites degrade through three degradation stages. In the first stage, the sample with max load of inorganic particles resulted in the diffusion as the rate-controlling process, while in the second, denoted as the main stage, thermal degradation of all samples proceeded via the same accelerating reaction type. However, at higher mass fraction of inorganic particles, the addition of the magnesium hydroxide particles altered the mechanism of thermal degradation of polyethylene oxide. [ABSTRACT FROM AUTHOR]

A series of high temperature resistant adhesives were synthesis from 2,2'-Bis-(4-cyanatophenyl) (BADCy), polyethersulfone (PES) and N, N'-4,4'-diphenylmethane bismaleimide (BMI) by solvent-free method. The effect of BMI content on the curing behavior, thermal, mechanical, fracture morphology, adhesive and thermal aging properties were studied. With the addition of BMI, the curing activation energy of resin increases from 67.44 kJ/mol of BMI-0 to 69.22 kJ/mol of BMI-30. The reason is mainly due to the higher activation energy of BMI self-polymerization. The BADCy/PES/BMI resin has a wider processing window (BMI-20 has the lowest viscosity in the range of 96°–182 °C), and the processing window becomes wider as the BMI content increases. More interestingly, as BMI content increases, resins toughness decreases and lap shear strength at room temperature decreases (from 31.4 MPa of BMI-0 to 20.0 MPa of BMI-30), but the high temperature performance increases as BMI content increases (temperature for 5% weight loss under N2 atmosphere of BADCy/PES/BMI increase from 404 °C of BMI-0 to 413 °C of BMI-30). [ABSTRACT FROM AUTHOR]

A novel yellow emitting double perovskite La2MgTiO6:Dy3+ phosphor was synthesized by a high-temperature solid-phase method. The emission spectra of La2MgTiO6:Dy3+ phosphor show three emission bands at 479 nm (blue), 573 nm (yellow), and 668 nm (red) at 351 nm excitation owing to the 4F9/2-6H15/2, 4F9/2-6H13/2, and 4F9/2-6H11/2 energy level jumps of Dy3+ ions, respectively. The concentration quenching of the phosphor sample at x = 0.07 mol is caused by dipole–dipole interaction. La2MgTiO6: Dy3+ phosphor has superior thermal stability with a luminous intensity of 85.6% at 423 K. The activation energy of the Dy3+ ion is 0.18 eV. The Commission Internationale de I'Eclairage (CIE) coordinates for the phosphors were calculated in the white light region, and the correlated color temperature (CCT) values are in the range of 4376–4586 K for warm white light. The results show that La2MgTiO6:Dy3+ phosphors may be a potential for application in w-LEDs. [ABSTRACT FROM AUTHOR]

The main contribution of this research is the study of the effect of thermal inertia in the activation energy in calcium aluminate cement pastes. For this, several formulations of calcium aluminate cement pastes (CACPs) with 51 wt% and 71 wt% of alumina (Al2O3) were made at 0.4 water-to-cement ratio, and with additions of 0.0 wt% and 20 wt% of silica content. The characterisation was done using X-ray fluorescence and X-ray diffraction, and the behaviour of the phases with temperature was studied using thermal gravimetric analysis, including the corresponding derivative thermogravimetry (DTG). The influence of the thermal inertia on the activation energies and its dependence on the heating rate is established. The effect of thermal inertia on peaks of DTG curves and activation energies is analysed. The activation energies for dehydroxylation of the gibbsite were calculated based on the Kissenger–Akahira–Sunose method. The activation energy values obtained, in kJ/mol, for CACP71 – 0, 20 wt% and CACP51 – 0, 20 wt% silica content were 19.9, 6.37 and 19.8, 17.2, respectively. The influence of silica on phase formation, activation energies and the effect of thermal inertia is also analysed. [ABSTRACT FROM AUTHOR]

Materials with low melting point and high energy density have become the focus of research on energy‐containing materials thanks to their superb detonation performance and wide applications. This paper proposed a new synthetic route for an energy‐containing compound 1‐trinitromethyl‐3‐nitro‐1,2,4‐triazole (TNMNT), using 3‐nitro‐1,2,4‐triazole as the raw material, low toxic chloroacetone as the substitute and KBr as the catalyst. These substances reacted at 70 °C for 3 h in a DMF reaction solvent system. The intermediate 1‐acetonyl‐3‐nitro‐1,2,4‐triazole (ANT) was obtained with a yield of 38 %. The nitration process increased the volume ratio of mixed nitric and sulfuric acids (1 : 3), and the reaction time was 36 h. TNMNT as a nitrogen‐rich compound having low melting point and high energy density was synthesized with a yield of 43 %. Compared with the traditional process, the experimental period was significantly shortened, and this synthetic method proved more environment‐friendly. Scanning Electron Microscopy (SEM), Differential Scanning Calorimeter (DSC) and mechanical sensitivity tests were performed on the products. It was found that the melting and decomposition points of TNMNT were 100.5 °C and 166.4 °C, respectively, the characteristic drop height H50 was 21.3 cm, and the frictional sensitivity was 56 %. Results show that the TNMNT crystals synthesized by this new route have better morphology, higher purity, and lower melting point. Compared with the raw material, the introduction of the trinitromethyl group produced higher mechanical sensitivity than other compounds having low melting point. Calculation of the thermal decomposition parameters found: activation energy of 104.4 kJ ⋅ mol−1, pre‐exponential factor of 2.27×1010 s−1, activation enthalpy of 100.9 kJ ⋅ mol−1, activation entropy of 57.98 J ⋅ mol−1 ⋅ K−1, and activation free energy of 125.72 kJ ⋅ mol−1. [ABSTRACT FROM AUTHOR]

The water absorption, chemical resistance, and biological properties are contributing factors to the overall performance of bio-composites, especially for outdoor applications. The functional properties of bio-composites are dependent on the interfacial bonding mechanism, which is controlled by the surface modification and processing parameters of natural fibers. Therefore, this study aims to investigate the potential of enhancing the mukwa/polylactide (mukwa/PLA) interface through an economic and ecological surface modification of recycled mukwa wood fibers via alkali-laccase modification. The fabricated biocomposites intended for making durable farm poles for semi-arid conditions of Southern Africa were characterized via water absorption, chemical resistance, thickness swelling, hardness, and thermal properties. Less thickness swelling and water absorption were found on the alkali-laccase/PLA composites. The lessdense (1.09 g/cm³ ) alkali-laccase treated composites showed better chemical resistance. Much swelling of the composites was observed on the 40% nitric acid (HNO3), while 60% NaOH shrunk the composites and PLA by <3.5%. The laccase/ PLA bio-composite showed a maximum thermal stability of 733 °C. The activation energy (Ea) optimized on the laccase/PLA composite with the highest of 104 kJ mol−1. Maximum crystallinity of 45.8% was achieved on the untreated/PLA composites. The alkali-laccase modification maximized the hardness of composites with 35.45 HV on alkali-laccase/PLA. [ABSTRACT FROM AUTHOR]

Polycarbonate (PC) /graphene nanocomposite was prepared using multilayer graphene (MLG) with loadings of 0.5, 1, and 3 wt% via melt mixing process. Morphological, structural, and thermal properties of the PC/MLG nanocomposites are investigated to look into the influence of MLG on the nanocomposite. A significant increase (∼6.4°C) in glass transition temperature is observed upon the addition of 3 wt% of MLG into the polycarbonate matrix. This increase in glass transition temperature may be due to the interaction between the MLG and polycarbonate polymer matrix. The specific heat capacity of pure PC and PC/MLG nanocomposites varies linearly with temperature below their glass transition. Upon the addition of MLGs, the overall thermal stability of PC/MLG nanocomposites increases with MLG loadings. A maximum increase about 29.23°C in T onset of thermal decomposition is observed in PC/MLG nanocomposite having 3 wt% of MLG loading. The activation energy (Ea) of thermal decomposition is also calculated by kinetic analysis of thermal decomposition of the PC/MLG nanocomposites using Horowitz–Metzger and Broido's methods. [ABSTRACT FROM AUTHOR]

This study aims to investigate the thermal properties of the phase transformation that may occur with the effect of temperature in Cu-14.70wt.%Al-4.72wt.%Ni shape memory alloy. The sample was annealed at 1203 K for 30 min in an argon atmosphere and then cooled rapidly in salt-ice water. By using Differential Scanning Calorimetry (DSC), the martensitic phase transformation parameters of the sample were found. The activation energy required for these transformations was calculated using the Kissinger, Augis-Bennett, and Takhor methods. Thermogravimetric Analysis (TGA) measurements investigated the mass changes that may occur with the effect of temperature. Surface morphology was analyzed using an optical micrograph. [ABSTRACT FROM AUTHOR]

Natural fiber composites are gaining more attention in automobile and aerospace industries due to its light weight with better performance. However, its performance is affected by the critical environment such as high temperature. Hence, analyzing the thermal stability of materials is paramount important. In this investigation, natural fiber-based composite was fabricated using Indian almond (I) and Veli karuvelam fibers (V) and its thermal stability was analyzed. Totally, five composites were fabricated viz. I:V(0:1) – 60 wt% epoxy and 40 wt% Veli karuvelam, I:V(1:3) – 60 wt% epoxy, 10 wt% Indian almond, and 30 wt% Veli karuvelam, I:V(1:1) – 60 wt% epoxy, 20 wt% Indian almond, and 20 wt% Veli karuvelam, I:V(3:1) – 60 wt% epoxy, 30 wt% Indian almond, and 10 wt% Veli karuvelam, and I:V(1:0) – 60 wt% epoxy and 40 wt% Indian almond. Thermogravimetric analysis was made, and the best composite was selected, which was further involved into thermal analysis, and the activation energies were determined by KAS and FWO kinetic models. Results showed that the I:V(0:1) composite showed the superior thermal stability compared to all other composites, and an onset degradation temperature of 387.64°C was observed. Further, the average activation energies determined by FWO and KAS models were showed as 51.73 and 42.19 kJ/mol, respectively, for I:V(0:1) composite. Hence, this investigation concludes that the I:V(0:1) composite could be a better candidate in the automobile and aviation fields to adopt the thermal environment. [ABSTRACT FROM AUTHOR]

In this study, thermal properties and curing kinetics of composites based on epoxy resin and talc as safer bio-based filler were investigated by differential scanning calorimetry (DSC). The study revealed that the curing profiles of all epoxy composites with talc were slightly identical with that of neat epoxy. Initial curing temperatures and curing rates of all composites were lower than that of neat epoxy. The glass transition temperature (Tg) of the neat epoxy and its composites was also studied using DSC and found at (95, 94.4, 86.5, and 86.6 °C, for pure epoxy, epoxy/talc: 10%, 20%, and 30 wt%, respectively). Kinetic parameters such as activation energy (Eα), pre-exponential factor (A), and curing temperatures at four different heating rates (10, 15, 20, and 25 °C/min) were also evaluated by means of two isoconversional models, namely Kissinger and Ozawa methods. The results obtained by both models showed that the composites have smooth and single exothermic peak which occurs in the same temperature range correspond to that of neat epoxy as well as comparable kinetics parameters. The obtained activation energy values for curing of epoxy with different talc contents calculated by two methods were ranging from 50 to 65 kJ/mol., while the typical value of the neat epoxy resins is 45 kJ/mol. Furthermore, all curing enthalpy values of composites were (127–140 J/g) and lower per the normal range for curing enthalpy of neat epoxy systems (148 J/g). Finally, it was proved that the incorporation of talc in epoxy resin allows manufacturing low-cost composite with acceptable thermal and curing properties. [ABSTRACT FROM AUTHOR]

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Phosphate glass with different Al2O3 and Na2CO3 compositions [80NaH2PO4-(20-x) Na2CO3-xAl2O3 with a step from 0 to 4] were prepared through melt quenching technique furnace at 900 °C. In order to determine the structure and microstructure modification of the samples after heat treatment the IR and Raman spectroscopy were performed. The X-ray diffraction (XRD) result shows an amorphous character of the prepared glass. The result obtained by differential scanning calorimetry (DSC) reveals a good thermal stability in the temperature range of 25 to 400 °C. The impedance Nyquist diagrams were investigated and modeled by resistors and constant phase elements (CPE) equivalent circuits. These measurements show a non-Debye type dielectric relaxation. Both AC and DC conductivity, dielectric constant, and loss factors were determined. Thermal activation energies were also calculated. A changes in the electrical conductivity and activation energy depend upon the chemical composition were observed. Also, a transition in the conduction mechanism from ionic to mixed ionic polaronic was noted. In the same line, electrical modulus and dielectric loss parameters are also deduced. Their frequency and temperature dependency exhibited relaxation behavior. Likewise, activation energies value obtained from the analysis of M’’ and those obtained from the conductivity are closes, which proves the optimal character of the preparation conditions.

The development of photoresponsive shape memory materials based on the photothermal conversion properties of lignin and the low activation energy of the dynamic covalent borate bond is of great importance. In this paper, a kind of lignin-based vitrimer polymer (LBP) containing dynamic boronic ester bonds was prepared by a "sulfhydryl-epoxy" click reaction and etherification reaction. The results show that the rigid segment EP-EL (lignin-based epoxy resin) and BDB (2,2′-(1,4-phenylene)-bis-[4-mercapto-1,3,2-dioxaneborane]) with benzene ring structure can impart tensile strength (20.8 MPa) to the LBP, while the flexible segment PEG imparts good elongation at break (15 %). The dynamic binding and dissociation exchange mechanism of the boronic ester bonds enables LBP to exhibit thermal remodelling properties (up to 36.2 %) and water-assisted self-healing properties at room temperature (up to 49.0 %). In addition, LBP exhibits excellent thermal and light-responsive shape memory properties due to its own photothermal conversion performance (photothermal conversion efficiency up to 18.2 %) and the dynamic boronic ester bond thermal activation bond exchange mechanism. The insulating properties of LBP make it suitable for use in high temperature protection circuit devices and light-responsive circuit devices. This study provides new insights into the design and application of Vitrimer and photoresponsive shape memory polymers, and also offers a new avenue for high-value utilization of lignin. [Display omitted] • Combining the low activation energy of boronic ester bonds with the photothermal properties of lignin • Solar responsive shape memory material based on lignin produced for the first time • LBP is applied to high temperature protection circuit devices and light response circuit devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fusion of covalent adaptable networks (CANs) with different mechanical properties using the diverse dynamic chemical bond. • CANs containing bi-dynamic bonds illustrate synergism and variable activation energy. • CANs exhibit outstanding puncture resistance properties and mechanical properties. Covalent adaptable networks (CANs) are widely used because of their outstanding mechanical properties and reprocessibility. However, these materials can only be recycled with mono-dynamic bonding networks during recovery. Here, we report that fused polymer CANs containing bi-dynamic bonds with adjustable mechanical properties are achieved through the dynamic behavior of the β -amino ester bond and the enamine-one bond. The β -amino ester bond-based CANs (P1) and the enamine-one bond-based CANs (P5) were prepared using tris(2-aminoethyl)amine (TREN) and m-xylylenediamine (MXDA) with hexanediol diacrylate and hexane-1, 6-diyl dipropiolate via click reaction, respectively. The mechanical and thermal properties of the fused films obtained after grinding and mixing at room temperature were comparable to those of CANs containing bi-dynamic bonds obtained by pre-mixing TREN and MXDA. Dynamic exchange and topological bond formation by the β -amino ester and the enamine-one at the interface are shown at the molecular level and with high uniformity. CANs containing bi-dynamic bonds showed synergism in stress relaxation experiments, demonstrating variable activation energies over a range of the temperature window. Owing to their excellent puncture resistance, the prepared materials can be used in flexible devices, energy-storage equipment, and various other applications. [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethane (TPU) nanocomposites (TPU/μmAl2O3‐ACA/nmAl2O3) with excellent mechanical, thermal stability and thermal conductivity were fabricated by co‐incorporating aluminate coupling agent DL‐411 chemically functionalized micron Al2O3 (μmAl2O3‐ACA) and nano‐Al2O3 (nmAl2O3) through melt blending method. FTIR analysis indicated that DL‐411 has been successfully grafted on the surface of μmAl2O3, which was beneficial to the homogeneous dispersion of Al2O3 particles and enhancements of interfacial interactions between Al2O3 particles and TPU matrix. Adding μmAl2O3‐ACA and nmAl2O3 simultaneously showed obvious synergistic effects on improving the mechanical properties of TPU nanocomposites. The optimum mechanical properties were obtained at the mass ratio of μmAl2O3‐ACA to nmAl2O3 of 3:1. Both μmAl2O3‐ACA and nmAl2O3 particles were homogeneously dispersed, constructing relatively perfect thermal conductivity networks, as verified by FESEM and PLM observations. The thermal conductivity (k) of TPU nanocomposites increased continuously with the addition of μmAl2O3‐ACA/nmAl2O3 particles, and the optimal k (0.28 W/m K) was achieved when the mass ratio of μmAl2O3‐ACA to nmAl2O3 was 3:1, which increased by 53% compared with pure TPU (k = 0.183 W/m K). TGA showed that, in contrast to those of pure TPU, the maximum decomposition temperature of TPU/μmAl2O3‐ACA/nmAl2O3 nanocomposites increased by 77.77°C, and the decomposition activation energy of TPU nanocomposite enhanced by 178%. [ABSTRACT FROM AUTHOR]

To study the thermal decomposition behavior of 4,4′-azobis(1,2,4-triazole) (ATRZ), the non-isothermal thermal decomposition kinetics of ATRZ were studied using the thermogravimetric–differential scanning calorimetry (TG–DSC) method. The TG–DSC of ATRZ was analyzed at heating rates of 5, 10, 15, and 20 K·min−1 in an argon atmosphere. The thermal decomposition kinetic parameters at peak temperature (Tp), such as apparent activation energy (Ea) and pre-exponential factor (lgA) of ATRZ, were calculated using the Kissinger, Ozawa, and Satava–Sestak methods. Ea and lgA calculated using the Kissinger, Ozawa, and Satava–Sestak methods are very close, at 780.2 kJ·mol−1/70.5 s−1, 751.1 kJ·mol−1/71.8 s−1, and 762.1 kJ·mol−1/71.8 s−1, respectively. Using a combination of three methods, the reaction mechanism function g(α) of ATRZ was obtained. The results show that the decomposition temperature of ATRZ is about 310 °C, and the decomposition is rapidly exothermic. The pyrolysis path of ATRZ was investigated through a pyrolysis-gas chromatography mass spectrometry (PY-GC/MS) experiment. ATRZ has three different decomposition paths and finally generates N2, HC-N-CH, N≡C-N, and HC=N-C≡N. The laser ignition combustion duration of ATRZ was 0.5033 s and the peak temperature was 1913 °C. The laser ignition combustion duration of ATRZ+CL-20 was 1.0277 s and the peak temperature was 2105 °C. The rapid energy release rate of ATRZ promotes the combustion energy release of CL-20. [ABSTRACT FROM AUTHOR]

Diamond due to its outstanding optical, electrical, mechanical and thermal properties finds an important place in electronic, opto-electronic and quantum technologies. Recent progresses showing superconductivity in diamond by boron doping has opened up many avenues including its applications in SQUID devices especially with polycrystalline diamond films. Granular boron doped diamond films find applications in quantum inductance devices where high surface inductance is required. Particularly important are the defect centers in diamond like nitrogen-vacancy (N-V), silicon vacancy (SiV) and other color centers which are ideal candidates for next generation quantum hardware systems. For efficient device applications, an indispensable need remains for a substitutional donor in diamond lattice that yields a lower thermal activation energy at room temperature. In this review, a comprehensive summary of research and the technological challenges has been reported including some of the results on nitrogen doping in polycrystalline diamond to understand the transport phenomenon emphasizing on its possible future applications. [ABSTRACT FROM AUTHOR]

The isolation of cellulosic fibers and their applications in composite materials have drawn considerable interest due to their outstanding thermal and mechanical properties combined with light-weight character, biodegradability, and renewability. Bamboo is a fast-growing plant, and its properties include sustainability and excellent tensile strength. In this study, bamboo fibers from the culms and shoots of Dendrocalamus asper were treated with 5 wt% sodium hydroxide and subjected to ultrasonication for 5 hours to obtain bamboo cellulose. Infra-red spectra showed that lignin and hemicelluloses were removed after treatment. With the removal of amorphous cellulosic regions, both cellulosic fibers exhibited higher decomposition temperatures than the raw fibers. Thermogravimetric analysis confirmed that both types of bamboo cellulose had a peak decomposition temperature at 408 °C. Cellulose isolated from the bamboo shoots exhibited similar chemical and thermal properties, indicating its huge potential as an alternative to mature bamboo culms. [ABSTRACT FROM AUTHOR]

In this work, FOX-7 (1,1-diamino-2,2-dinitroethylene)-based polymeric microspheres were successfully prepared by the spray-drying method, in which recrystallized FOX-7 grains were integrated with Viton (dipolymers of hexafluoropropylene and vinylidene fluoride). FOX-7/Viton granules were prepared by water slurry method for comparison. FOX-7/Viton microspheres possessed a hollow structure with a typical shell thickness of 870 nm. The particle size of FOX-7/Viton grains on the shell of microspheres was significantly reduced from 33.31 μm (raw FOX-7) to 750 nm. Compared with raw FOX-7 and FOX-7/Viton granules prepared by the water slurry method, FOX-7/Viton hollow microspheres possessed a lower value of apparent activation energy in the thermal decomposition process and a higher characteristic height (H50), which indicates increased thermal decomposition rate and better safety performance. VST test showed that three samples had acceptable thermal stability. [ABSTRACT FROM AUTHOR]