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The concurrent enhancement of toughness, electrical conductivity, and thermal stability in polycrystalline diamond composites represents a formidable challenge. Here, a novel diamond-TiC composites (referred to as DTC) with high fracture toughness and conductivity were synthesized through a high-temperature and high-pressure reaction sintering process utilizing two precursors: diamond mixtures containing TiH 2 and Ti-coated diamonds. On the one hand, the inherent bonding and encasing of TiC onto the diamond matrix form a heterogeneous structure, providing high strength and excellent fracture toughness up to 11.6 MPa·m1/2. On the other hand, the established oxygen barrier and current pathway offer a thermal stability of 765 °C and high conductivity up to 837 S·m−1. Remarkably, this rare combination of mechanical, electrical, and thermal properties has been realized within a single material under relatively moderate sintering conditions, thus positioning diamond-TiC composites as a promising ceramic for electrical applications in high-stress environments. [ABSTRACT FROM AUTHOR]

Purpose: One of the low-cost minerals that can be used as reinforcing filler in polymer industry is pumice powder. Pumice is a highly porous volcanic glass formed during explosive eruptions. This pumice has received significant interest because of its large surface area with various polar groups and can be processed easily. Design/methodology/approach: This study is carried out to investigate the effect of partial replacement of silica (as traditional filler) by naturally occurring pumice powder to improve the thermal and mechanical properties of nitrile butadiene rubber cured with electron beam radiation (doses from 25 to 150 kGy). Findings: The results indicated that the addition of pumice powder increase the tensile strength at lower doses up to 75 kGy (especially at concentration of 5 phr). Besides, an improvement in the thermal stability was attained with the addition of pumice powder. Originality/value: Pumice powder is volcanic-based alumina and silica which is mainly composed of SiO2. It has porous structure which is formed by dissolved gases precipitated during the cooling as the lava hurtles through air. Due to its porous structure, it has low density and high thermal insulation. It also has high temperature and chemical resistance, for these reasons it became preferable material to be used as filler in the plastic and rubber industry. [ABSTRACT FROM AUTHOR]

Ceramic fibers are an important thermal insulation material that are not only widely used in extreme conditions, but also play an important role in energy conservation and energy efficiency for sustainable development. However, the practical application of conventional ceramic fibers has a high thermal conductivity in high-temperature environments, which hinders their widespread application. Here, a novel lamellar structured porous SiTiOC/C composite ceramic materials was designed and prepared with excellent thermal insulating properties. The unique microstructure endowed the porous SiTiOC/C composite ceramic materials with a high IR refractive index (93.81%) and an ultra-low thermal conductivity (0.0562 W·m−1 K−1 at 600 ℃). In addition, the porous SiTiOC/C composite ceramic materials not only exhibited excellent mechanical properties (4.46 MPa at 800 ℃), but also demonstrated impressive oxidation resistance and thermal stability. In summary, the proposed porous SiTiOC/C composite ceramic materials provide a reference for the development of high-temperature insulation with good mechanical properties. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive investigation into the thermal stability of superlattice-like (SLL) thin films fabricated by varying the sputtering sequences of the SLL [Ge8Sb92(25nm)/GeTe(25nm)]1 and SLL [GeTe(25nm)/Ge8Sb92(25nm)]1 configurations. Our results reveal significantly enhanced ten-year data retention (Tten) for both thin films measured at 124.3 °C and 151.9 °C, respectively. These values surpass the Tten of Ge2Sb2Te5 (85 °C), clearly demonstrating the superior thermal stability of the studied SLL configurations. Interestingly, we also observe a distinct difference in the thermal stability between the two SLL configurations. The superior thermal stability of SLL [GeTe(25nm)/Ge8Sb92(25nm)]1 is attributed to the diffusion of the Sb precipitated phase from Ge8Sb92 to GeTe. This diffusion process effectively reduces the impact of the Sb phase on the thermal stability of the thin film. In contrast, in the case of SLL [Ge8Sb92(25nm)/GeTe(25nm)]1, the presence of the Sb precipitated phase in Ge8Sb92 facilitates the crystallization of GeTe, leading to reduced thermal stability. These findings underscore the significant influence of the sputtering sequence on the atomic behavior and thermal properties of superlattice-like phase change materials. Such insights provide a robust foundation for the design and exploration of novel phase change materials with improved thermal performance. [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 pursuing enhanced performance for electronic applications, we synthesized ferroelectric materials, specifically Ba(1-x)Nd2x/3TiO3 (BNdTx) nanoceramics, utilizing solid-state reaction techniques coupled with microwave heating treatment. Our investigation involved varying Nd3+-doping levels (x = 0%, 2%, 4%, and 8%) to tailor the material's properties. XRD analysis confirmed the presence of a single-phase tetragonal perovskite structure (space group P4mm). A comprehensive examination of the partial density of states for both undoped and Nd3+-doped BaTiO3 was undertaken to discern the impact of Nd3+-doping on the energy bands. Microscopic analysis revealed the presence of pores in the samples, accompanied by a reduction in grain size with increasing Nd3+ content. The introduction of Nd3+ induced a shift in the Curie temperature (TC) towards room temperature. Simultaneously, the dielectric characteristics exhibited a consistent value above 1900, with a low loss of less than 5% observed across a range of temperatures (30–100 °C). Notably, the sample with x = 4% demonstrated thermally stable dielectric properties, suggesting its potential suitability as a material for Multilayer Ceramic Capacitor (MLCC) applications. Integrating microwave sintering and ball milling techniques is a significant development in advanced materials engineering, specifically in producing Multi-Layer Ceramic Capacitors (MLCC). The practical implementation of these novel methodologies is essential in decreasing particle size, which is a critical determinant in improving thermal stability. Ball milling further refines the particle size distribution, whereas microwave sintering guarantees a more uniform and fine-grained microstructure through its rapid and effective heating capabilities. The capacitors acquire enhanced thermal stability and a more refined material granularity through this synergistic combination. By achieving a more uniform and compact ceramic structure, these processes result in a finer particle size, enhancing the overall performance and dependability of MLCC capacitors. The increasing need for miniaturized and high-performance electronic components has focused on utilizing microwave sintering and ball milling. These processes are at the forefront of technological advancements in the pursuit of improved thermal properties and increased efficiency in manufacturing MLCC capacitors. [ABSTRACT FROM AUTHOR]

A novel quinoxaline-based phthalonitrile monomer, namely, 4,4′-(((quinoxaline-2,3-diylbis (oxy))bis (3,1-phenylene))bis (oxy))di-phthalonitrile (QDOP), was successfully synthesized by nucleophilic substitution reaction, which exhibits a low melting point (85°C) and a wide processing window (150°C). The QDOP monomer was cured with 4-aminophenoxy phthalonitrile (APPH) as catalyst by different temperature programs, and the curing process and kinetics were discussed in detail by non-isothermal differential scanning calorimetric (DSC). The QDOP polymer mainly forms triazine, isoindoline and phthalocyanine structure, as revealed by Fourier transform infrared (FTIR) spectroscopy, and its properties improved with the increase of post-curing temperature and curing time. After post-curing at 380°C, the polymer exhibited high storage modulus (3731 MPa), high glass-transition temperature (>400°C), and outstanding thermal stability and thermal oxidation stability. [ABSTRACT FROM AUTHOR]

Only 0.1% of polyurethanes available on the market are from renewable sources. With increasing concern about climate change, the substitution of monomers derived from petrochemical sources and the application of eco-friendly synthesis processes is crucial for the development of biomaterials. Therefore, polyhydroxyurethanes have been utilized, as their synthesis route allows for the carbonation of vegetable oils with carbon dioxide and the substitution of isocyanates known for their high toxicity, carcinogenicity, and petrochemical origin. In this study, polyhydroxyurethanes were obtained from carbonated soybean oil in combination with two diamines, one that is aliphatic (1,4-butadiamine (putrescine)) and another that is cycloaliphatic (1,3-cyclohexanobis(methylamine)). Four polyhydroxyurethanes were obtained, showing stability in hydrolytic and oxidative media, thermal stability above 200 °C, tensile strength between 0.9 and 1.1 MPa, an elongation at break between 81 and 222%, a water absorption rate up 102%, and contact angles between 63.70 and 101.39. New formulations of bio-based NIPHUs can be developed with the inclusion of a cycloaliphatic diamine (CHM) for the improvement of mechanical properties, which represents a more sustainable process for obtaining NIPHUs with the physicochemical, mechanical, and thermal properties required for the preparation of wound dressings. [ABSTRACT FROM AUTHOR]

In this study, a highly dense GdB 6 bulk ceramic material was fabricated using one-step in-situ reaction spark plasma sintering technology. The sample with a relative density of 96.7 % and a purity of 96.9 wt% was successfully obtained by sintering at 1800 °C for 30 min under a uniaxial pressure of 50 MPa. The Vickers hardness, elastic modulus and fracture toughness of the as-obtained GdB 6 bulk ceramics were 18.9 GPa, 209 GPa and 1.6 MPa·m1/2, respectively. The thermal conductivity of GdB 6 at room temperature was 28.68 W·m−1·K−1, 70 % of which was mainly attributed to phonon vibration, while the remaining 30 % to the electrical thermal conductivity. In addition, the as-obtained GdB 6 ceramics showed no phase transformation after heat treatment at a relatively high temperature of 2100 °C for 20 min in Ar atmosphere. The highly covalent octahedral boron framework played a critical role in maintaining the phase stability of the GdB 6 crystal lattice. This suggested that GdB 6 ceramics could be used as potential ultra-high temperature ceramics for aerospace applications and high-power vacuum electronic devices operated at high temperatures. [ABSTRACT FROM AUTHOR]

Physical parameters are necessary to determine the suitability of the chalcogenide materials for specific applications. The present study reports the physical characteristics of the multicomponent GeTe2-x(SeSb)x (x = 0, 0.2, 0.4, 0.6) chalcogenide glasses synthesised by the melt-quench technique. The differential scanning calorimetric (DSC) technique has been used at separate heating rates β = 5, 10, 15, 20 °C / min. XRD and SEM–EDX studies have been carried out for structural and morphological analyses. The average coordination number and constraints of the compound have been calculated which indicates that the composition forms a glassy system. Lone pair electrons present in the composition have been evaluated. R parameter has a value greater than 1, indicating that the composition has sufficient chalcogen, chalcogen–chalcogen and heteropolar bonds. The overall bond energy of the compound has been calculated using the chemical bonding approach to understand the fine-structure properties of the compound. Cohesive energy has been observed to increase with composition. Thermal stability, glass transition temperature and glass forming ability of the compound have been calculated using different relations like Saad and Poulin relation, Dieztal relation, Hurby parameter (Hr) and reduced glass transition temperature (Trg) and studied theoretically to examine the thermal stability of the composition that shows that the prepared samples are suitable for data storage. [ABSTRACT FROM AUTHOR]

Starch is present in high amount in various cereals, fruits and roots & tubers which finds major application in industry. Commercially, starch is rarely consumed or processed in its native form, thus modification of starch is widely used method for increasing its application and process stability. Due to the high demand for starch in industrial applications, researchers were driven to hunt for new sources of starch, including modification of starch through green processing. Thermal properties are significant reference parameters for evaluating the quality of starch when it comes to cooking and processing. Modification of starches affects the thermal properties, which are widely studied using Differential scanning calorimeter or Thermogravimetric analysis. It could lead to a better understanding of starch's thermal properties including factors influencing and expand its commercial applications as a thickener, extender, fat replacer, etc. in more depth. Therefore, the review presents the classification of starches, factors influencing the thermal properties, measurement methods and thermal properties of starch in its native and modified form. Further, this review concludes that extensive research on the thermal properties of new sources of starch, as well as modified starch, is required to boost thermal stability and extend industrial applications. [ABSTRACT FROM AUTHOR]

A series of seven stable amide derivatives based on indole‐3‐carboxaldehyde were synthesized with high yields using various aliphatic and aromatic acyl chlorides, triethylamine and DMAP as the catalyst at room temperature. Structural characterization was performed using FT‐IR, 1 H‐NMR, 13C‐NMR and LC–MS techniques. To develop bioactive material, acetalization of water‐soluble polyvinyl alcohol was achieved by reacting one of the N‐acyl derivatives, 1‐propionylindole‐3‐carboxaldehyde, in the presence of a p‐TSA catalyst to form polyvinyl acetal with pendant bioactive groups. The polymer was analyzed using 1 H‐NMR, FT‐IR, TGA, DSC, FE‐SEM and EDX spectroscopic techniques. The polymer was water‐insoluble with enhanced thermal stability compared to pure polyvinyl alcohol. This approach for developing N‐acyl derivatives of indole‐3‐carboxaldehyde and then reacting one of the monomers with polyvinyl alcohol to improve its thermal properties and stability in humid conditions has proven successful. [ABSTRACT FROM AUTHOR]

To synthesize lead-free primary explosives with good thermal stability, pyridine-2-carbohydrazide (2-PDCA) was used to prepare a novel energetic copper perchlorate complex (ECCs-1), which was structurally characterized by infrared spectroscopy, NMR, and elemental analysis. Its thermal decomposition properties were investigated by thermogravimetry and a synchrotron thermal analyzer, and the sensitivity was tested by the BAM method. The laser ignition experiment and the lead plate tests show that the ECCs-1 complex has a good detonation performance with a high thermal decomposition temperature (215.6 °C) and moderate sensitivity (impact sensitivity = 3 J and friction sensitivity = 5 N). [ABSTRACT FROM AUTHOR]

Woven flax-carbon hybrid polyamide biocomposites offer a blend of carbon fibers' mechanical strength and flax's environmental advantages, potentially developing material applications. This study investigated their thermal behavior, degradation kinetics, and durability to water uptake and relative humidity exposure and compared them with pure flax and carbon composites with the same matrix. The hybrid composite exhibited intermediate water/moisture absorption levels between pure flax and carbon composites, with 7.2% water absorption and 3.5% moisture absorption. It also displayed comparable thermal degradation resistance to the carbon composite, effectively maintaining its weight up to 300 °C. Further analysis revealed that the hybrid composite exhibited a decomposition energy of 268 kJ/mol, slightly lower than the carbon composite's value of 288.5 kJ/mol, indicating similar thermal stability. Isothermal lifetime estimation, employing the activation energy (Ed) and degree of conversion facilitated by the Model Free Kinetics method, indicated a 41% higher service life of the hybrid laminate at room temperature compared to the carbon laminate. These insights are crucial for understanding the industrial applications of these materials without compromising durability. [ABSTRACT FROM AUTHOR]

Phenol-formaldehyde foams are lightweight polymer composites that are prepared by foaming the resin. The major goal is to reduce the weight of the composite significantly while increasing thermal stability and sorption behaviour.This paper gives information about the characteristics of the reinforced PF foams with (CNT/CNT-IL) by FT-IR spectrum, SEM images, and investigations on the thermal properties by TGA/DSC analysis. BET was used as a tool for porosity analysis and oil sorption of the foams is also investigated. According to the TGA data, adding nano-silica and CNT/CNT-IL to PF foams improves thermal stability. The sorption experiments for unmodified and modified foams with nano-silica, and CNT/CNT-IL reveal that increasing the nanofiller content results in higher sorption capacities. [ABSTRACT FROM AUTHOR]

Drug candidates must undergo thermal evaluation as early as possible in the preclinical phase of drug development because undesirable changes in their structure and physicochemical properties may result in decreased pharmacological activity or enhanced toxicity. Hence, the detailed evaluation of nitrogen-rich heterocyclic esters as potential drug candidates, i.e., imidazolidinoannelated triazinylformic acid ethyl esters 1–3 (where R1 = 4–CH3 or 4–OCH3 or 4–Cl, and R2 = –COOC2H5) and imidazolidinoannelated triazinylacetic acid methyl esters 4–6 (where R1 = 4–CH3 or 4–OCH3 or 4–Cl, and R2 = –CH2COOCH3)—in terms of their melting points, melting enthalpy values, thermal stabilities, pyrolysis, and oxidative decomposition course—has been carried out, using the simultaneous thermal analysis methods (TG/DTG/DSC) coupled with spectroscopic techniques (FTIR and QMS). It was found that the melting process (documented as one sharp peak related to the solid–liquid phase transition) of the investigated esters proceeded without their thermal decomposition. It was confirmed that the melting points of the tested compounds increased in relation to R1 and R2 as follows: 2 (R1 = 4–OCH3; R2 = –COOC2H5) < 6 (R1 = 4–Cl; R2 = –CH2COOCH3) < 5 (R1 = 4–OCH3; R2 = –CH2COOCH3) < 3 (R1 = 4–Cl; R2 = –COOC2H5) < 1 (R1 = 4–CH3; R2 = –COOC2H5) < 4 (R1 = 4–CH3; R2 = –CH2COOCH3). All polynitrogenated heterocyclic esters proved to be thermally stable up to 250 °C in inert and oxidising conditions, although 1–3 were characterised by higher thermal stability compared to 4–6. The results confirmed that both the pyrolysis and the oxidative decomposition of heterocyclic ethyl formates/methyl acetates with para-substitutions at the phenyl moiety proceed according to the radical mechanism. In inert conditions, the pyrolysis process of the studied molecules occurred with the homolytic breaking of the C–C, C–N, and C–O bonds. This led to the emission of alcohol (ethanol in the case of 1–3 or methanol in the case of 4–6), NH3, HCN, HNCO, aldehydes, CO2, CH4, HCl, aromatics, and H2O. In turn, in the presence of air, cleavage of the C–C, C–N, and C–O bonds connected with some oxidation and combustion processes took place. This led to the emission of the corresponding alcohol depending on the analysed class of heterocyclic esters, NH3, HCN, HNCO, aldehydes, N2, NO/NO2, CO, CO2, HCl, aromatics, and H2O. Additionally, after some biological tests, it was proven that all nitrogen-rich heterocyclic esters—as potential drug candidates—are safe for erythrocytes, and some of them are able to protect red blood cells from oxidative stress-induced damage. [ABSTRACT FROM AUTHOR]

The ZrO 2 fiber paper exhibits excellent thermal insulation properties, however, its limited mechanical strength and insufficient thermal stability hinder its widespread applications. The composite fiber papers, using mullite fibers possessing a high aspect ratio and exceptional thermal stability combined with ZrO 2 fibers, were fabricated via a vacuum-assisted filtration method. This method involved the successive stacking of composite fibers with alumina sol, using vacuum-induced directed water flow to create a layered structure reminiscent of nacre. The layered structure of the nacre, which demonstrates remarkable strength and hardness, has also served as a source of inspiration for the architectural design of the fiber paper. The tensile strength of pure ZrO 2 fiber paper was significantly enhanced by the addition of 7 wt% mullite fibers, resulting in a remarkable increase to 0.1805 kN/m. The paper exhibited exceptional resistance to bending, maintaining 96 % of its bending strength even after undergoing 100 cycles. The thermal shrinkage of the composite paper, containing 15 wt% mullite fibers, was reduced from 17.75 % observed in pure ZrO 2 fiber paper to a mere 1.32 % after undergoing heat treatment at a temperature of 1300 °C for 2 h. The composite paper, measuring 5 mm in thickness and consisting of 7 wt% compositions, displayed exceptional thermal insulation properties when exposed to a hot side temperature of 1370 °C. It effectively insulated temperatures up to approximately 1000 °C. [ABSTRACT FROM AUTHOR]

Recently, CaO‐doped (≤4 mol.%) tetragonal zirconia (CaSZ) ceramic was recommended as a potential alternative to yttria‐stabilized ZrO2 (YSZ). Here, we investigate the limits of starting particle sizes on the stability of tetragonal (t) phase and other associated benefits on measured properties. Synthesized CaSZ powders calcined with different temperatures were used as a mono‐sized or mixed (i.e., two different calcination temperatures) batch fraction for making dense CaSZ ceramic. The mixed‐batch powders were found to be far more efficient in stabilizing the t‐phase in ceramic. Compared to YSZ, CaSZ recorded remarkable enhancement in toughness (up to 8.3 MPa m$\sqrt {\mathrm{m}} $). Contrary to YSZ, CaSZ ceramic demonstrated outstanding thermal stability. [ABSTRACT FROM AUTHOR]

The long-term operation of motors induces substantial alterations in the surface conductivity and nonlinear coefficient of anti-corona paint, diminishing its efficacy and jeopardizing the longevity of large motors. Hence, the development of high-performance anti-corona paint holds paramount importance in ensuring motor safety. In this study, we integrate two nano-fillers, namely silicon carbide (SiC) and organic montmorillonite (O-MMT), into a composite matrix comprising micron silicon carbide and epoxy resin (SiC/EP). Subsequently, three distinct types of anti-corona paint are formulated: SiC/EP, Nano-SiC/EP, and O-MMT/SiC/EP. Remarkably, O-MMT/SiC/EP exhibits a glass transition temperature about 25 °C higher than that of SiC/EP, underscoring its superior thermal properties. Moreover, the introduction of nano-fillers markedly augments the surface conductivity of the anti-corona paint. Aging tests, conducted across varying temperatures, unveil a notable reduction in the fluctuation range of surface conductivity post-aging. Initially, the nonlinear coefficients exhibit a declining trend, succeeded by an ascending trajectory. The O-MMT/SiC/EP composite displays a maximum nonlinearity coefficient of 1.465 and a minimum of 1.382. Furthermore, the incorporation of nanofillers amplifies the dielectric thermal stability of epoxy resin composites, with O-MMT/SiC/EP showcasing the pinnacle of thermal endurance. Overall, our findings elucidate the efficacy of nano-fillers in enhancing the performance and longevity of anti-corona paint, particularly highlighting the exceptional attributes of the O-MMT/SiC/EP composite in bolstering motor safety through improved thermal stability and electrical properties. [ABSTRACT FROM AUTHOR]

The development of high-power piezoelectric ceramics with superior piezoelectric properties and broad temperature usage ranges is vital for the thriving progress of electromechanical applications. However, achieving high piezoelectricity, high mechanical quality factor, and temperature stability often presents a trade-off. In this study, we present an advanced ceramic material with excellent high-power piezoelectric properties and superior temperature stability. The piezoelectric coefficient d 33 reaches 348 pC N−1, the electromechanical coupling factor k p is 54%, the mechanical quality factor Q m is 1501, the dielectric loss tanδ is 0.35%, and the d 33 variation is less than 10% within 25–210 °C in 0.05Pb(Mg1/3Nb2/3)O 3 -0.05Pb(Mn 1/3 Sb 2/3)O 3 -0.9Pb 0.95 Sr 0.05 (Zr 0.48 Ti 0.52)O 3 ceramic. The excellent piezoelectricity is attributed to the enhancement of intrinsic ionic displacement and reversible domains wall motion because of symmetry-conforming short-range distribution of oxygen vacancy, while the high Q m is a result of increased domain size and oxygen vacancy. The outstanding temperature stability is related to the stable non-180°domains structure due to the oxygen vacancy pinning effect. These properties hold great potential for advanced applications, particularly for piezoelectric high-power applications requiring constant d 33 over a broad temperature range. [ABSTRACT FROM AUTHOR]

Background: Hyaluronic acid liquid‐core hydrogel beads (HA‐LHB) is a good way for oral intake of HA. However, HA may affect the reaction–diffusion of sodium alginate (SA) and Ca2+ leading to poor mechanical properties, since HA is a polyanionic electrolyte having electrostatic effect and a certain spatial site‐blocking effect. Results: The mechanical properties of HA‐LHB were modified from bathing solution, core solution and secondary calcium bath time. The mechanical properties varied with the SA structure and concentration in bathing solution, where SA with high G (guluronic acid) segment compounded with SA with high M (mannuronic acid) segment at a mass ratio of 7:3 with a 11 g kg−1 concentration showed the best mechanical properties. The secondary calcium bath can greatly improve the mechanical properties due to the tight network formed by bidirectional crosslinking, and 15 min reaction reached the plateau if Ca2+ is sufficient. And the mechanical properties were positively correlated with calcium lactate concentration only at <70 g kg−1 in core solution, but the diffusion of Ca2+ was hindered by the tight gel network at higher concentrations. Moreover, the mechanical properties can be maintained during heat treatment, due to the rearrangement of alginate network structure. Conclusion: Our results suggested that the problem of poor mechanical properties of LHB in the presence of high HA concentration can be avoided by process control, which may broaden the development of HA and popping boba market. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

2,6-Di-tert-butyl-4-methylphenol (BHT) is an excellent antioxidant that is easily oxidized to 2,6-di-tert-butyl-4-hydroperoxyl-4-methyl-2,5-cyclohexadienone (BHTOOH). For the safety of BHT production and usage, it is meaningful to study the thermal stability and decomposition properties of BHT and BHTOOH. In this paper, the thermal decomposition properties of BHT and BHTOOH were compared by the mini closed pressure vessel test (MCPVT) and differential scanning calorimetry (DSC). Their kinetics of thermal decomposition were studied using thermogravimetric analysis (TGA). The thermal decomposition products of BHT and BHTOOH were analyzed by gas chromatography-mass spectrometry (GC–MS). The results show that there was no significant change in temperature pressure when BHT was warmed up under a nitrogen atmosphere, indicating that BHT was stable within 400 K. The thermal decomposition reaction of BHTOOH was rapid with an initial reaction temperature of 375.2 K. The initial exothermic temperature (Ti) and heat release (QDSC) of DSC were 384.9 K and 865.0 J g−1, respectively. The apparent activation energies (Ea) for the thermal decomposition reactions of BHT and BHTOOH calculated by the Kissinger method were 151.8 kJ mol−1 and 66.07 kJ mol−1, respectively. The main decomposition products of BHT were isobutene and 2-tert-butyl-4-methylphenol. The thermal decomposition products of BHTOOH included BHT, 2,6-di-tert-butyl-4-ethylphenol, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, 4,4′-(1,2-ethanediyl) bis [2,6-bis (1,1-dimethylethyl) phenol, etc. Based on the thermal decomposition behavior and products, the reaction pathway has been described. These results indicate that BHT is a potential thermal hazard during production, storage and application. For the safety of the chemical industry, the oxidation of BHT should be avoided. [ABSTRACT FROM AUTHOR]

In this paper, polysulfonamide‐based composite materials (SCF/PSAf composite) reinforced by the short carbon fiber were prepared. The mechanical properties and thermal stability of SCF/PSAf composite were characterized experimentally and compared with those of polysulfonamide‐based single‐polymer composites (PSA SPCs). Results showed that SCF/PSAf composites exhibit higher thermal stability due to the excellent thermal stability of SCFs. Furthermore, the additional short carbon fibers also considerably enhance the flexure strength of PSA SPCs due to the strong interfacial bonding between SCF and PSAf. The properties and understanding of SCF/PSAf composite obtained in this work can benefit further applications of this novel composite material. Highlights: SCF/PSAf composites are prepared by hot compression, and the adhesion between the PSA matrix and SCF is good.The flexural strength of the SCF/PSAf composite is about 2.5 times higher than that of PSA SPCs.The storage modulus of SCF/PSAf composites is about 3.5 times higher than that of PSA SPCs.The addition of short carbon fibers helps to improve the thermal properties of SCF/PSAf composites.SCF/PSAf composite has a stronger ability to resist deformation and a higher operating temperature than the PSA SPCs do. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is a bioresorbable and biodegradable polymer extensively used in various biomedical and engineering applications. In this study, we investigated the mass loss and thermal properties of PLA-multi-walled carbon nanotube (MWCNT) composites under simulated physiological conditions. The composites were prepared by melting PLA with 0.1, 0.5, 1.0, and 5.0 wt% MWCNTs using an ultrasonic agitator, and FTIR analysis confirmed composite formation. Subsequently, the composites were subjected to hydrolysis under simulated physiological conditions (pH 7.4 and 37 °C) for up to 60 days. The results revealed that the mass loss of the composites decreased with increasing MWCNT content, suggesting that the presence of MWCNTs decelerated the hydrolysis process. On day 58, the mass loss of pure PLA was 12.5%, decreasing to 8.34% with 0.1% MWCNT, 5.94% with 0.5% MWCNT, 4.59% with 1% MWCNT, and 3.54% with 5.0% MWCNT. This study offers valuable insights into the behavior of PLA-MWCNT composites under physiologically simulated conditions, facilitating the development of new polymer composites with enhanced thermal stability and degradation resistance for biomedical applications. [ABSTRACT FROM AUTHOR]

The vinyl-polydimethylsiloxane (v-PDMS) composite reinforced by micron size ZDMA particles previously showed high modulus, thermal stability, solvent-proofness, and good processing ability. However, its poor damping properties limited usages. Thus, incorporation of new polymers into the composite was imperative to improve its loss factors. With a similar solubility parameter and good damping properties, isobutylene-isoprene rubber (IIR) was melt-blended in, then heat-pressed and cross-linked. The v-PDMS/ZDMA/IIR composites gotten were characterized by scanning electric microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), mechanical tests, dynamic mechanical analysis (DMA) and thermal gravimetric analysis (TGA) methods. The IR spectra of the composites illustrated that the incorporation of IIR was successful. The SEM observation showed good dispersion of the IIR, and the increasing deformation on the surface with growing dosage of IIR. The incorporation of IIR rubber decreased the composite's modulus sharply and also the tensile strength, but improved the elongation and damping properties of the v-PDMS/ZDMA composites at low temperature. The TGA test results in N2 gas showed the composites had good thermal stability below 350 °C, then deteriorated at higher temperature owing to the decomposition of the IIR at 400 °C. The decomposition activation energy at 400 °C was determined by the Kissinger method. [ABSTRACT FROM AUTHOR]

Urea cyanurate, as a new nitrogen-rich organic-based heat stabilizer, for the enhancement to thermal properties of polyvinyl chloride (PVC) is prepared via the simple precipitation method, in this study. Characterization, thermal and mechanical properties of the stabilized PVC were examined by means of fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA/DTG), X-ray photoelectron spectroscopy (XPS) measurements, discoloration test, congo red test and the weight-loss method, thermal aging test, and tensile analysis. Results showed that the thermal stability of PVC is improved after the addition of urea cyanurate in PVC formulation and weight loss related to HCl releasing in the normal PVC processing temperature (180°C) is less than 1%. Enhancement of the thermal properties and stability time of the PVC lead to decreased degradation tendency. Oven-aging test result showed that the color change during degradation process of PVC samples improved by adding the urea cyanurate. The tensile strength of stabilized samples were about 42%, higher as compared to the pure PVC. The optimum and best results for improving the thermal and mechanical properties of PVC were obtained by incorporating the 3 wt % of the urea cyanurate. [ABSTRACT FROM AUTHOR]

This work evaluates the effect of plasma treatment on the wettability, dynamic mechanical and thermal properties of compression-molded composite panels produced from wood fiber (WF) and polypropylene (PP). Initially, WF was treated with different plasma durations (60, 120, and 180 s radiation). Afterward, the contact angle, moisture uptake, storage modulus, loss modulus, damping loss, and weight loss of the specimens prepared from untreated and plasma-treated were evaluated. Results revealed that the plasma treatment facilitates the interactions between WF and PP, and increases the adhesion properties. Compared with the lowest contact angle of 74.8° for the untreated specimens, the highest contact angle was found in the treated specimens around 79.06°, 81.29°, and 82.7°, using 60 and 15 using 180 s plasma radiations. Furthermore, the water absorption of the specimens reduced as a result of plasma treatment. The plasma-treated specimens demonstrated better molecular restriction and larger dynamic modulus than the unmodified ones. The tan δ peak signifying the glass transition temperature of composites shifted to a higher temperature, in the presence of plasma treatment. It was noted that the thermal stability of the composite panels produced from plasma-treated wood was remarkably improved. [ABSTRACT FROM AUTHOR]

A new series of high-temperature resistant bisphthalonitrile resins containing trifluoromethyl groups were prepared based on 4,4'-(hexafluoroisopropylidene) bisphthalonitrile (BFPh), which was toughened by hexafluoroisopropylidene-containing poly (aryl ether nitrile) oligomer capped by phthalonitrile (FPEN-Ph) in the different content. In addition, glass fiber reinforced composites were prepared by hot pressing process. The structure of the oligomer was characterized by FTIR and 1HNMR. The curing behavior of the blends was studied by DSC. Thermal stability and mechanical properties were also studied. The results showed that the introduction of appropriate content of FPEN-Ph could improve the reactivity of the curing reaction. TGA and DMA results showed that the cured polymers and composites had excellent thermal properties. The residual mass of FPEN-Ph content of 10% at 800°C was 72.4%, and the 5% thermal degradation temperature (T5%) under inert atmosphere was 530°C. The flexural strength of glass fiber reinforced composites was about 592.7 MPa, and the shear strength was about 61.6 MPa, showing excellent mechanical properties. The high-tech thermosetting resin was toughened and enhanced at the same time without reducing heat resistance. [ABSTRACT FROM AUTHOR]

Improvement in thermal stability is especially important for the oxide/oxide composites, which are widely applied at high temperatures. Herein, the continuous alumina fiber reinforced alumina matrix (Al 2 O 3 /Al 2 O 3) composites were fabricated at 1200–1400 °C using Al 2 O 3 powders with a mean size of 0.6 μm. The Al 2 O 3 /Al 2 O 3 composite fabricated at 1300 °C achieved a high flexural strength of 392.9 ± 20.1 MPa and a high interlaminar shear strength of 20.6 ± 1.0 MPa. After exposure at 1000 °C for 100 h and 1400 °C for 10 min, the 1300 °C fabricated Al 2 O 3 /Al 2 O 3 composite showed no significant reduction in mechanical properties. A slight decrease in mechanical properties was observed after aging at 1200 °C for 100 h. The high strength retention after the heat treatment benefited from the coarse Al 2 O 3 powders, which could not be easily sintered at high temperatures. This work can expand the selection of the Al 2 O 3 /Al 2 O 3 composites for potential applications at service temperatures as high as 1400 °C for a short term. [ABSTRACT FROM AUTHOR]

Current highly integrated devices require heat interface materials with excellent heat conductivity. A simple approach was employed to synthesize thermally conductive and outstanding thermal stability nanocomposite. Calcium carbonate nanoparticles (nano CaCO 3) reinforced with reduced graphene oxide (rGO) nanoparticles (rGO/CaCO 3) are synthesized using a novel process, and the effect of rGO in CaCO 3 structure is examined by Field Emission Scanning Electron Microscope, X-ray diffraction, TGA-DTA, and thermal conductivity. The experimental results show that adding rGO resulted in higher crystallinity and thermal stability. As the wt.% of rGO increases from 1 to 5%, the crystallite size was suppressed by 21.06%, 27.39%, 32.48%, 41.5%, and 45.30%, respectively, compared to the pure nano-CaCO 3. Additionally, rGO enhances the thermal conductivity by 35.31% and thermal diffusivity to 1.834 mm2/s by adding 5% rGO. [ABSTRACT FROM AUTHOR]

Melt-quenching techniques were employed to produce a series of Nd 2 O 3 doped Al 2 O 3 –Na 2 O–WO 3 –B 2 O 3 glasses. Structure, optical, and thermal properties were investigated to illustrate the effectiveness of the Nd3+ ions in enhancement performance and analyze their behaviour. Nd 2 O 3 demonstrably contributed to the composite, as evidenced by evaluating all features. The density marginally rises with the addition of Nd 2 O 3 instead of B 2 O 3. The relevant physical characteristics had been calculated. The structure was analyzed by FTIR measurement and identified the vibration modes of varied concentrations. From FTIR spectra, N 4 values were reckoned, and the conversion of the network structure unit from BO 3 to BO 4 was verified. Numerous significant peaks have been caught in the absorption bands of the UV–Vis–NIR measurement. Optical bandgap and band tail are determined. DSC measurements were utilized to identify the thermal characteristics. As Nd3+ ions increased, glass thermal stability improved. Overall, the Nd3+ ion modifier rule was realized. [ABSTRACT FROM AUTHOR]

Recently, there has been an increasing trend in utilizing lignocellulosic fiber reinforced composites in structural applications within the construction and automobile industries, replacing conventional materials based on metals and their derivatives. In the present study, Erythrina variegata fibers (EVFs) were subjected to a number of chemical treatments individually (alkalization, benzoyl peroxide, potassium permanganate, and stearic acid treatments). The effects of these chemical treatments on the EVFs were examined through chemical composition analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). This comprehensive analysis aimed to assess the suitability of the chemically treated EVFs for use as reinforcement in thermoset polymer matrix composites. The alkali treated fibers (AEVFs) were found as optimum and were then used as reinforcement in epoxy adhesives. Different fiber loadings (0, 5, 10, 15, 20, and 25 wt%) were incorporated into the epoxy matrix to investigate their effects on the properties of the composites. Therefore, the tensile strength, flexural strength, impact strength, and thermal stability of the prepared composites were evaluated under controlled laboratory conditions. The findings collectively suggested that the epoxy composites reinforced with 20 wt% of AEVFs exhibited promising characteristics for lightweight structural applications. [ABSTRACT FROM AUTHOR]

The glass composition (70-x)PbO-(30-y)B2O3-(x+y)AlF3, where x and y ranges from 0 to 20 mol%, were prepared using the conventional melt-quenching-annealing technique. The structural and thermal properties of the glasses were comprehensively analyzed using techniques like Differential Thermal Analysis (DTA), Dilatometry, Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). XRD confirmed the amorphous, non-crystalline structure of the glasses. The glass network was found to be composed of structural units such as PbO4, BO4, BO3 and AlO6 using FTIR spectroscopy. FTIR analysis revealed significant structural changes, including the transformation of BO4 to BO3 units and the increase in non-bridging bonds, particularly with higher AlF3 content. DTA was instrumental in determining characteristic temperatures, such as the glass transition, melting, and peak crystallization temperatures, along with glass stability parameters (ΔT, Hr, Tgr) for all samples. The study found that the addition of AlF3 led to a decrease in these characteristic temperatures when replacing B2O3, but an increase when replacing PbO. Variations in the density and thermal expansion of the lead borate glass were observed upon the addition of AlF3, decreasing when substituting for PbO and increasing when substituting for B2O3. These findings provide insights into the properties of oxyfluoride glasses, paving the way for future optimization in their composition for varied applications. [ABSTRACT FROM AUTHOR]

Coal gasification fine slag (CGFS) is a by-product of gasification process of gasification beds that pollutes the environment. To make the utilization of CGF more efficient, poly (vinyl chloride) (PVC)/CGFS composites were prepared via a melt blending process, and their mechanical and thermal properties were investigated. In order to dig deeper into the decomposition mechanism, the thermal degradation kinetics were systematically analyzed by drawing non-isothermal heat maps based on the Flynn-Wall-Ozawa, Friedman, and Kissinger model-free methods. According to the results, the properties of all tests vary significantly with CGFS content. In particular, at a the CGFS content of 20 phr, the tensile strength (tensile modulus) and flexural strength (flexural modulus) of CGFS-20 were 13.5% (47.8%) and 13.9% (41.6%) higher, respectively, than those of conventional CGFS-0 composites. However, the impact strength decreases with the increase of CGFS content. At the same time, the addition of CGFS suppresses the mass conversion rate and improves the thermal stability of PVC composites at high temperature, and the final residual mass reaches 31%, which is 12.7% higher than that of pure PVC. The kinetic analysis of thermal decomposition shows that CGFS promotes the initial degradation of the composites reduces the activation energy of the reaction, and at the same time endows them with higher thermal stability in the high-temperature phase. [ABSTRACT FROM AUTHOR]

Sustainable building materials with excellent thermal stability and sound insulation are crucial for eco-friendly construction. This study investigates biocomposites made from cellulose pulp reinforced with beeswax, fir resin, and natural fillers like horsetail, rice flour, and fir needles. Eight formulations were obtained, and their thermal resistance, oxidation temperature, and acoustic properties were evaluated. Biocomposites exhibited significant improvements compared to conventional materials. Oxidation temperature onset increased by 60–70 °C compared to polyurethane foam or recycled textiles, reaching 280–290 °C. Sound absorption coefficients ranged from 0.15 to 0.78, with some formulations exceeding 0.5 across mid-frequencies, indicating good sound-dampening potential. These findings demonstrate the promise of these biocomposites for sustainable construction, offering a balance of thermal and acoustic performance alongside environmental and health benefits. [ABSTRACT FROM AUTHOR]

In this work, the EVOH/Ti3C2 composite fibers were prepared via electrospinning and the effect of added Ti3C2 on the structure and properties of electrospun EVOH fibrous membranes was further investigated. The morphology, crystal structure, thermal properties, wettability, tensile properties, as well as air permeability and water vapor permeability of as-prepared EVOH/Ti3C2 composite fibers were studied. The Ti3C2 is uniformly loaded onto the surface and inside the composite fiber and affects the fiber diameters. Furthermore, The Ti3C2 self-orients along the fiber axis and does not change the crystal structure of the electrospun EVOH fibers, improving the crystallinity and thermal stability of the electrospun EVOH/Ti3C2 fibrous membranes. With the increase in the Ti3C2 concentration in the electrospinning polymer solution, the addition of Ti3C2 not only rapidly improves the wettability of the fibrous membranes, but also enhances their air permeability, compared with the pristine electrospun EVOH fibrous membranes. The experimental results provide theoretical guidance for the preparation of Ti3C2 composite fibers, and also expand the application of electrospun EVOH and EVOH/Ti3C2 fibrous membranes. [ABSTRACT FROM AUTHOR]

A series of novel biodegradable homopolymers and copolymers of L -lactide (LA) and δ-valerolactone (VL) were polymerized at 165 °C using stannous octoate as a catalyst initiated with salicylic acid or benzyl alcohol via ring-expansion or ring-opening polymerization, respectively. The polymer chain topology was suggested to be either cyclic or linear depending on the initiator used. The feeding molar ratio of LA : VL was changed to investigate the chain microstructure, thermal properties, as well as degradability of copolymers. 1H-NMR revealed that incorporating 30, 50, and 70 mol% VL provided blocky, gradient, and random chain copolymers, respectively. Increasing VL content relative to the LA content decreased the Tg, Tm, and crystallinity of the copolymers. All copolymers displayed higher thermal stability than PLA homopolymers due to the presence of the VL comonomer. The cyclic polymers showed higher Tg, lower Tm, and lower crystallinity than their linear counterparts. Furthermore, it was found that the degradability of the copolymers can be controlled by adjusting the compositions of VL and LA and their chain architecture. [ABSTRACT FROM AUTHOR]

The efficient inclusion of GNPs (graphene nanoplatelets) as an effective nano‐fillers for green polymer matrices produced with 28% of carbon originating from biomass tends to significantly improve mechanical and thermal properties. In the present work, green epoxy nanocomposites with low loading of (0.1, 0.25, and 0.5) wt% of the GNPs were made using a solution blending technique using acetone as the solvent. In mechanical stirring, the ultrasonic bath was used to ensure the efficient dispersion of GNPs within green epoxy. The resulting nanocomposites were comprehensively characterized and compared to unfilled green epoxy. Different tools were used to appraise morphological, thermal, thermo‐mechanical, and mechanical behavior. The results confirmed through FE‐SEM showed an optimal dispersion of GNPs with nanocomposites. The thermal degradation temperature (Td) of GNPs curve with 0.25 wt% loading was shifted toward higher temperature (from 336°C to 342°C) due to low percentage of loading of GNPs which showed an enhance thermal stability of polymer matrix with 0.25 wt% loading. The mechanical results were also in lined with previously published literature, in the tensile test 6.45% and hardness 13.3% increment was achieved. Overall, the results underscored significant improvements in green nanocomposite performance with low wt% of GNPs. Highlights: The study focuses on development and characterization of green epoxy nanocomposites, which utilize environmentally friendly materials as a matrix, highlighting the significance of sustainability.The study explores effects of low loading of GNPs in green epoxy nanocomposites. The results demonstrate significant improvements in mechanical and thermal properties with optimized presence of GNPs. This investigation provides insights into optimal amount of GNPs required to achieve improved properties.Research evaluates multifaceted analysis provides a holistic understanding of performance enhancements achieved through inclusion of GNPs. [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]

The current work concerned the thermal characteristic of Se0.75−xTe0.25Agx (0 ≤ x ≤ 0.1) chalcogenide glasses. Under non-isothermal conditions, differential scanning calorimetry has been used to evaluate the thermal stability of these compositions throughout the temperature identification of the glass transition, Tg, the initial crystallization temperature, Tin, the peak crystallization rate, Tp, and the melting temperature, Tm. Also, the kinetic factor Kr(T) is specified as a further indication of thermal stability. It was found that the Se0.71Te0.25Ag0.04 has the greatest capacity to form glass and the greatest glass thermal stability between these compositions. These findings have been explained using the average coordination numbers of the tested compositions. Also, in this work, we studied the crystallization kinetic of Se0.75−xTe0.25Agx (0 ≤ x ≤ 0.1) thick films via measuring the sheet resistance, Rs whose thickness is 1000 nm at heating rate 5 K min−1, in the 300–630 K temperature range. Two significant regions might be detected in the sheet resistance curve using this range and by considering how sheet resistance is derived according to temperature, one crystallization area is clearly present for the investigated films. The Avrami index was measured for both alloys and thick films. [ABSTRACT FROM AUTHOR]

In this study, wet ball milling and hot press methods were used to prepare nanocomposite from ultra-high molecular weight polyethylene (UHMWPE) as a matrix, and modified multi wall carbon nanotubes (MWCNTs) as reinforcement nano-additives. Two batches of MWCNTs were used (Pristine-MWCNTs-B1, and Pristine-MWCNTs-B2). First, the MWCNTs were oxidized (oxide-MWCNTs) by wet chemistry using strong acids, then further functionalized with an amide group (A-MWCNTs). Fourier-transform infrared spectroscopy (FTIR), and Thermal gravimetric analysis (TGA) results confirm the functionalization of the MWCNT with the amide group. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to examine the surface morphology and crystalline behavior of MWCNT after functionalization. Ball milling was used to mix the UHMWPE with pristine MWCNT (1.5% wt), Oxide-MWCNT (1.5% wt), and A-MWCNTs (0.5–2% wt). Then, hot press melting was used to prepare the nanocomposite sheets. Fourier transform infrared spectroscopy (FTIR) confirmed the impact of the balls milling process with time factor on UHMWPE crystallinity and the interaction of the functionalization MWCNT with the UHMWPE matrix. The structure (crystallinity, crystal size) was validated using X-ray diffraction (XRD) patterns. Thermal gravimetric analysis (TGA), differential scanning calorimeter (DSC), and universal testing machine (UTM) were utilized to analyze the structural, thermal, and mechanical properties of the nanocomposites, respectively. The results showed that UHMWPE crystallinity increased after 2 h of ball milling, while crystallinity decreased when pristine-MWCNT, oxide-MWCNTs, and A-MWCNTs (0.5–2 wt%) were added without affecting the crystal structure of UHMWPE. The results showed that adding 1.5 wt% A-MWCNTs-(B1, B2)/UHMWPE increased thermal stability by 16 °C and elongation at the break by up to 74% when used 1.5 wt% A-MWCNT-B1 and 2 wt% A-MWCNT-B2. This shows that the ball milling methods and amide group improved the dispersion and interface interaction between MWCNTs and UHMWPE matrix. [ABSTRACT FROM AUTHOR]

This study focused on an important global issue containing both environmental pollution control and energy storage. Polyaniline has been utilized as a supporting material to load paraffin in order to form highly thermal conducting and shape-stable phase change material (PCM). Three different weight percentages (wt%), i.e., 10, 15, and 20 wt%, of polyaniline have been used to obtain shape-stable composite materials. The paraffin leakage of the prepared samples PPCM1, PPCM2, and PPCM3 has been examined by 500 thermal cycles in a hot air oven at 80 °C. Among three samples, the PPCM3 composite with 20 wt% of polyaniline in paraffin has shown excellent leakage-bearing properties with only ~ 0.06% leakage after 500 thermal cycles. Further, the chemical, structural, and morphological analyses of the PPCM3 composite have been carried out by FTIR, XRD, and FESEM. The thermal performance of the prepared sample has been studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis, which revealed that the impregnation of polyaniline polymer has improved the thermal stability and thermal conductivity of paraffin with a small decrement in latent heat capacity of the PPCM3 composite. The latent heat of the composite decreased by 18.36% and thermal conductivity increased by ~ 65.45% for a 20 wt% concentration of polyaniline in paraffin with the maximum latent heat capacity. To check the thermal reliability of the formulated PPCM3 composite, the composite has been subjected to thermal cycling of 500 thermal cycles. With increased thermal conductivity, high latent heat capacity, good shape stability, excellent leakage-bearing capability, and improved thermal reliability, paraffin/polyaniline composite PCMs look promising for application in thermal energy storage areas. [ABSTRACT FROM AUTHOR]

The thermal stability of fullerenes plays a fundamental role in their synthesis and in their thermodynamic and kinetic properties. Here, we perform extensive molecular dynamics (MD) simulations using an accurate machine-learning-based Gaussian Approximation Potential (GAP-20) force field to investigate the energetic and thermal properties of the entire set of 1812 C 60 isomers. Our MD simulations predict a comprehensive and quantitative correlation between the relative isomerization energy distribution of the C 60 isomers and their thermal fragmentation temperatures. We find that the 1812 C 60 isomers span over an energetic range of over 400 kcal mol − 1 , where the majority of isomers (∼ 85%) lie in the range between 90 and 210 kcal mol − 1 above the most stable C 60 - I h buckminsterfullerene. Notably, the MD simulations show a clear statistical correlation between the relative energies of the C 60 isomers and their fragmentation temperature. The maximum fragmentation temperature is 4800 K for the C 60 - I h isomer and 3700 K for the energetically least stable isomer, where nearly 80% of isomers lie in a temperature window of 4000–4500 K. In addition, an Arrhenius-based approach is used to map the timescale gap between simulation and experiment and establish a connection between the MD simulations and fragmentation temperatures. [ABSTRACT FROM AUTHOR]

In this work, we present the effect of graphene nanoplatelets (GnPs) modification with ionic liquids (ILs). The textural properties of graphene nanoplatelets (GnPs) used as styrene-butadiene rubber's filler and the thermal properties of the composites obtained with the use of the mentioned fillers were investigated. GnPs were modified with 1-butylpyridinium bromide (BPyBr) and 4-methyl-1-butylpyridinium bromide (BmPyBr) through two different ways. One strategy has been to deposit the filler modifier from the solution. The second one involved the modification of the filler with ionic liquids in bulk during the preparation of elastomer blends. Settlement of the proposed ionic liquids onto the GnPs' surface led to significant changes in the textural characteristics. BPyBr has restricted the filler's microporosity, whereas BmPyBr has caused the formation of a more opened filler structure without the increase in its average pore size. GnPs modified with ILs led to reducing the temperature of vulcanization of SBR compounds and affected the thermal stability of the composites. [ABSTRACT FROM AUTHOR]

Composites with excellent flame retardant and mechanical properties are in high demand in the aerospace and various industrial fields. Glass fiber (GF) reinforced polyimide (PI) composites (GFRPCs) were fabricated using a simple ball milling and hot pressing technique. The effect of GF content on the thermal stability, mechanical and flame retardant properties of composites has been systematically studied. The Rockwell hardness of GFRPCs increase with increasing GF content, while the compressive strength, impact strength and flexural strength initially show an increase followed by a decrease due to the excellent dispersibility of the fillers and the strong interfacial interaction between the one‐dimensional GF and PI matrix. Thermogravimetric analysis results show that the addition of GF with very low thermal conductivity and excellent temperature resistance can effectively improve the thermal stability of PI. Adding GF into PI can obviously improve the limiting oxygen index value. Moreover, as the GF content increased, the time to ignition of the composites prolonged while total heat release decreased. These findings suggest a viable solution for enhancing both the flame retardance and mechanical properties of PI‐based composites. Highlights: GFRPCs with high GF content fabricated via ball milling‐hot pressing method.Silane modified GF obviously improves the thermal stability of PI matrix.GFRPCs‐28 exhibits superior mechanical properties.An increases in time to ignition (TTI) and mass residual rate (MRR) of the GFRPCs was observed on adding GF. [ABSTRACT FROM AUTHOR]

Intermolecular interactions and molecular configurations are of great significance for the formation of liquid crystals. During this study, a series of isomer compounds with biphenyl esters as rigid cores were synthesized, and their mesomorphic properties and thermal stability were investigated. Based on the same rigid core, compounds heptyl 4′‐methoxy‐[1,1′‐biphenyl]‐4‐carboxylate (1OBE7), propyl 4′‐(pentyloxy)‐[1,1′‐biphenyl]‐4‐carboxylate (5OBE3), ethyl 4′‐(hexyloxy)‐[1,1′‐biphenyl]‐4‐carboxylate (6OBE2) and methyl 4′‐(heptyloxy)‐[1,1′‐biphenyl]‐4‐carboxylate (7OBE1) have no mesophase, while compounds hexyl 4′‐ethoxy‐[1,1′‐biphenyl]‐4‐carboxylate (2OBE6), pentyl 4′‐propoxy‐[1,1′‐biphenyl]‐4‐carboxylate (3OBE5) and butyl 4′‐butoxy‐[1,1′‐biphenyl]‐4‐carboxylate (4OBE4) have multiple smectic mesophases, whereas the production of the smectic mesophase is due to the microphase separation between aromatic cores and the alkyl chains. Compound 3OBE5 exhibiting good thermal stability (The value of T5% is 258.3 °C). In addition, with the right shift of the functional group position, compound 4OBE4 formed the widest smectic mesophase. The results show that the mesophase properties and thermal stability of liquid crystals are related to the position of the functional group. [ABSTRACT FROM AUTHOR]

The laser ablation technique was utilized to fill the carboxy methyl cellulose (CMC) solution with zirconium dioxide (ZrO2) and copper oxide (CuO) nanoparticles with different concentrations. Different techniques have been used to study the physical behavior of fabricated compositions. CuO has shown different peaks at related to the monoclinic phase of the prepared CuO NPs lattice constants (JCPDS No. 02-1225). According FTIR results, ZrO2 has exhibited vibrating bands at 460 cm−1, 477 cm−1, 670 cm−1, and 690 cm−1 which are corresponding to Zr–O vibration. In addition, CuO has shown vibrating bands at 439, 494, and 594 cm−1. The dielectric properties have been investigated. The TGA results showed that the sample CMC-ZrO2-CuO/20 min has excellent thermal stability as the weight loss is 36% of its initial weight at 796 °C. The optical and electrical characterization showed that the addition of ZrO2 and CuO has changed and enhanced the electrical characterization of CMC. The enhancement in electrical conductivity of the system encourages it for electrical applications. [ABSTRACT FROM AUTHOR]

Utilizing triethylenediamine (DA), 1,3-propanesultone (PS), whose ring opens during the formation of the dizwiterion-intermediate DA-2PS, and the metal chlorides XCly, where X = Sn(IV), Zn(II),Al(III), Fe(III) and Mn(II), are used for the synthesis of five kinds of acidic metal-based functionalized ionic liquid catalysts ([DA-2PS][XCly]2). Their chemical structures, thermal stability and dual acidic active site were analyzed. We investigated the performance of [DA-2PS][XCly]2 in catalyzing the esterification reaction between 2,5-furandicarboxylic acid (FDCA) and ethylene glycol (EG) to synthesize poly (ethylene 2,5-furandicarboxylate)(PEF). Among the catalysts tested, [DA-2PS][SnCl5]2 exhibited the best catalytic performance under identical process parameters, and the optimal catalyst dosage was determined to be 0.05 mol% based on FDCA. The optimal conditions for the reaction were predicted using response surface methodology: a feed ratio of EG:FDCA = 1.96:1, an esterification temperature of 219.86 °C, a polycondensation temperature of 240.04 °C and a polycondensation time of 6.3 h, with a intrinsic viscosity of 0.67 dL·g−1. The resulting PEF was experimentally verified to exhibit an intrinsic viscosity of 0.68 dL·g−1 and a number average molecular weight of 28,820 g·mol−1. Finally, the structure and thermal properties of PEF were characterized. The results confirmed that PEF possessed the correct structure, exhibited high thermal stability and demonstrated excellent thermal properties. [ABSTRACT FROM AUTHOR]

Entropy plays a crucial role in designing new functional materials or enhancing material performance. The design of high entropy ceramics (HECs) introduces a larger composition space, thus the understanding of the correlation between the composition, entropy effect, and the performance of HECs is becoming increasingly important. In this work, to pursue superior properties, a series of CeNbO 4 -based solid solution ceramics with a maximum of 9 species cations in a single sublattice were synthesized by using high entropy configuration strategy. The interaction of composition, size disorder, and configurational entropy on the properties of HECs was emphasized. The potential conflict between high resistivity and low material constant of thermosensitive ceramics was overcome and thus achieving excellent thermal sensitivity properties having an extremely wide temperature range from room temperature to 1623 K and long-term high-temperature stability. This will bring innovative prospects for the design and application of high-temperature functional ceramics. [ABSTRACT FROM AUTHOR]

To evaluate thermal properties and promote the application of novel N-oxide amphoteric energetic compound 4,6-diamino-3-hydroxy-2-oxo-2,3-dihydro-1,3,5-triazine-1-oxide (DAOTO), thermal behaviors of DAOTO were studied systematically by differential scanning calorimeter (DSC), thermogravimetric analyzer (TG/DTG) and thermogravimetric-mass-infrared spectrometry (TG-MS-FTIR) techniques. Results showed that DAOTO has only an obvious exothermic decomposition process during the range of 250 ~ 350 °C with an extrapolated starting point temperature (Te) of 291.6 °C, a peak temperature (Tp) of 320.6 °C, a heat release of 1317 J g−1 and a corresponding mass loss of ~ 17%, at a heating rate of 10 °C min−1, and the kinetic equation of thermal decomposition process was obtained. The main thermal decomposition gas products of DAOTO are H2O, NH3 and CO, and the possible thermal decomposition process was analyzed. Besides, the specific heat capacity of DAOTO at 298.15 K was determined as 1.14 J g−1 K−1, and adiabatic time-to-explosion was calculated to be a certain value between 100 and 105 s. This work proved DAOTO having a good thermal stability and provided theoretical support for the application of DAOTO. [ABSTRACT FROM AUTHOR]