Search

Purpose: In everyday life, people generally wear two layers of clothes (a knitted vest and a knitted t-shirt) during the summer. It is essential to understand which types of innerwear and outerwear maximize comfort. The primary objective of this research is to investigate the influence of layering outerwear on innerwear, as well as the air gap between two layers, on thermal comfort properties. Design/methodology/approach: In this study, a total of 12 combinations were created from four vest fabrics and three T-shirt fabrics. The thermal properties (thermal conductivity, thermal resistance, thermal absorptivity, thermal diffusion and peak heat flow) were evaluated for the individual inner and outer layers. Each inner layer was layered with an outer layer to observe the effect of layering on the thermal properties. An air gap of 2 mm was introduced between the inner and outer layers to study the effect of air gap on thermal properties. Findings: Tencel fibre exhibits higher thermal conductivity and absorptivity than cotton and polyester. Upon layering an outer layer on an inner layer, the thermal conductivity and thermal absorptivity increase to a slight extent, thermal resistance and diffusion increase drastically and the peak heat flow reduces. With an air gap between the two layers, the thermal conductivity did not improve, the difference in thermal resistance among all the combinations reduced, the thermal absorptivity of the combination textiles was lower than that of the innerwear alone, the thermal diffusion increased and the peak heat flow diminished for all the combinations. Practical implications: In practice, this comprehensive thermal comfort analysis provides specific combinations of inner and outer articles of clothing that are most appropriate for enhancing comfort during the summer season. Originality/value: Though there are many studies on the effect of multilayer fabrics on thermal properties, no extensive research analyses the influence of innerwear and outerwear combinations on thermal comfort properties. [ABSTRACT FROM AUTHOR]

This study utilizes a multidisciplinary approach, combining simulation experiments, thermal expansion analysis, XRD, SEM, and physical property assessments to investigate the firing temperature in illitic-kaolinitic porcelain. Our findings indicate that the accuracy of the thermal expansion method depends on both the actual firing temperature and dwell time. When dwell time is uncertain, the method provides a range of possible actual firing temperatures, differing by approximately 100 °C. Remarkably, as the porcelain body nears full vitrification, the determined firing temperature tends to be notably higher. A critical analysis of previous research suggests potential overestimation of ancient kiln temperatures. Additionally, our study highlights the usefulness of bulk density, water absorption, porosity, and mullite content in determining dwell time. Overall, our research offers new insights into ancient porcelain firing processes. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) fiberwebs and multi‐ply assemblies of nettle woven reinforcement are used to develop a series of nettle/PLA biocomposites with different reinforcement orientations. The tensile strength, flexural strength, impact strength, and thermal properties of the biocomposites are found to improve by piling nettle fabrics and are also found to depend strongly on the piling architecture and the test direction. It is possible to obtain a biocomposite with higher degrees of isotropy and enhanced mechanical properties by using cross‐ply laminates. The three‐layered woven fabric reinforced PLA biocomposite with a reinforcement orientation 0°/45°/90° shows the best results among all the biocomposites developed in this study. The tensile strength, Young's (tensile) modulus, flexural strength, impact strength, storage modulus, and loss modulus of the biocomposite are found as 55.25 MPa, 6.30 GPa, 85.83 MPa, 63.74 J/m2, 10.08 GPa, and 0.75 GPa, respectively. In this biocomposite, a fair adhesion between matrix and reinforcement is noticed, and this is justified by retardation of crack propagation as well as by substantial energy dissipation. The thermal stability of the biocomposite does not get effected much, but the percent crystallinity increases by 25.84%. The degradation kinetics and the activation energy of the biocomposite are determined through a differential fitting of Arrhenius model. The soil burial test reveals 15.06% of weight loss and 50.56% strength loss for this biocomposite just after 20 days of burial under soil. Highlights: Multi‐ply architecture of woven fabric reinforcement in nettle/PLA biocomposites.Nearly isotropic biocomposite through angle‐ply orientation of reinforcement.Biocomposite with remarkable static and dynamic mechanical properties.Augmented kinetic parameters through model fitting of Arrhenius equation.Biocomposite with excellent thermo‐recyclability and biodegradability. [ABSTRACT FROM AUTHOR]

The physicochemical properties of high-molecular weight compounds based on N,N-diallyl-N′-acyllhydrazines were studied. Based on the results of thermal analysis it was established that sorbents are stable up to 160–210 °C; the destruction of the initial N,N-diallyl-N′-acyllhydrazines starts at lower temperatures. The stability of sorbents in various media, the values of static exchange capacities for hydrogen ions and hydroxide ions ( SEC H + and SEC OH − ), and isoelectric points of the surface were determined. Samples for further study of the rare earth metals sorption were selected. [ABSTRACT FROM AUTHOR]

The paper presents and discusses the results of a study of the thermal properties of cement composites with different contents of magnetite aggregate (0%, 20%, 40% and 60% by volume). The effect of grain size on the evaluated thermal properties was also investigated. For this purpose, concrete containing 50% by volume of magnetite aggregate with four different fractions (1–2 mm, 2–4 mm, 4–8 mm and 8–16 mm) was used. Thermal parameters were evaluated on specimens fully saturated with water and dried to a constant mass at 65 °C. The series with varying grain sizes of magnetite achieved thermal conductivity values in the range of 2.76–3.03 W/(m·K) and 2.00–2.21 W/(m·K) at full water saturation and after drying to a constant mass, respectively. In the case of the series with 20% magnetite by volume, the thermal conductivity was 2.65 W/(m·K) and 1.99 W/(m·K) for the material fully saturated with water and dried to a constant mass, respectively. The series with a 60% volume share of magnetite obtained values of this parameter of 3.47 W/(m·K) and 2.66 W/(m·K), respectively, under the same assumptions. [ABSTRACT FROM AUTHOR]

The manufacturing method influences the properties of the produced components. This work investigates the influence of manufacturing methods, such as fused deposition modeling (3D printing) and injection molding, on the water absorption and mechanical and thermal properties of the specimens produced from neat bio-based poly(lactic acid) (PLA) polymer and poly(lactic acid)/wood composites. Acrylonitrile butadiene styrene (ABS) acts as the reference material due to its low water absorption and good functional properties. The printing layer thickness is one of the factors that affects the properties of a 3D-printed specimen. The investigation includes two different layer thicknesses (0.2 mm and 0.3 mm) while maintaining uniform overall thickness of the specimens across two manufacturing methods. 3D-printed specimens absorb significantly higher amounts of water than the injection-molded specimens, and the increase in the layer thickness of the 3D-printed specimens contributes to further increased water absorption. However, the swelling due to water absorption in 3D-printed specimens decreases upon increased layer thickness. The tensile, flexural, and impact properties of all of the specimens decrease after water absorption, while the properties improve upon decreasing the layer thickness. Higher porosity upon increasing the layer thickness is the predominant factor. The results from dynamic mechanical analysis and microscopy validate the outcomes. The results from this experimental study highlight the limitations of additive manufacturing. [ABSTRACT FROM AUTHOR]

Summary: In frozen part‐baked bread technology, starch is influenced by various processing factors. This study aimed to investigate the effect of part‐baking time, freezing rate and frozen storage time on pasting, thermal and structural properties of part‐baked bread. Wheat dough was part‐baked for 0, 3 or 6 min and frozen at −20 °C using two freezing rates: slow (0.15 °C min−1) or fast (1.45 °C min−1). Next, samples were stored in frozen conditions for 56 days and analysed every 14 days for starch damage, pasting properties, thermal and X‐ray analysis. The level of damaged starch increased with 3 min (69.3%), and 6 min (88.8%) of part‐baking time for both freezing rates compared to no part‐baked. In pasting analyses, peak viscosity decreased 27.3% and 38.4% for 3 and 6 min of part‐baking time, respectively, at 0 days of frozen storage; however, this tendency was observed for all frozen storage time. The gelatinisation enthalpy (ΔHg) decreased as part‐baking time increased, showing the maximum reduction at 6 min of part‐baked (94.9%). In X‐ray diffraction analyses at 3 and 6 min of part‐baking, the intensity of the signal increased 4.4% and 10.9%, respectively, probably due to the starch gelatinisation. These results can serve as a valuable guide for developing strategies to enhance the quality of part‐baked bread and improve production performance. [ABSTRACT FROM AUTHOR]

1,3,5‐trinitroso‐1,3,5‐triazine (R‐Salt) is an insensitive energetic that has previously been used as an improvised explosive. The work presented here is a comprehensive study on the thermal properties and chemical characterization of R‐Salt. Thermal analysis was performed via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) which found both crude and recrystallized R‐Salt have similar thermal properties but the selected lid impacted both the thermal profile and onset temperature. Chemical characterization performed via Raman, Fourier‐transform Infrared (FT‐IR), nuclear magnetic resonance (NMR) spectroscopy and high‐resolution mass spectrometry indicate that recrystallization does not quantitatively improve the purity of crude R‐Salt., The reported NMR 2D‐HSQC, FT‐IR, and Raman spectra are the first to be reported within the published literature, as to the authors' knowledge. [ABSTRACT FROM AUTHOR]

2,3-dihydro-5,6,7,8-tetranitro-1,4-benzodioxine (TNBD), molecular formula = C8H4N4O10, is a completely nitrated aromatic ring 1,4-benzodioxane derivative. The convenient method of TNBD synthesis was developed (yield = 81%). The detailed structure of this compound was investigated by X-ray crystallography. The results of the thermal analysis (TG) obtained with twice re-crystallized material revealed the onset at 240 °C (partial sublimation started) and melting at 286 °C. The investigated material degraded completely at 290–329 °C. The experimental density of 1.85 g/cm3 of TNBD was determined by X-ray crystallography. The spectral properties of TNBD (NMR, FT-IR and Raman) were explored. The detonation properties of TNBD calculated by the EXPLO 5 code were slightly superior in comparison to standard high-energy material—tetryl (detonation velocity of TNBD—7727 m/s; detonation pressure—278 kbar; and tetryl—7570 m/s and 226.4 kbar at 1.614 g/cm3, or 260 kbar at higher density at 1.71 g/cm3. The obtained preliminary results might suggest TNBD can be a potential thermostable high-energy and -density material (HEDM). [ABSTRACT FROM AUTHOR]

Advanced electronics technology is moving towards smaller footprints and higher computational power. In order to achieve this, advanced packaging techniques are currently being considered, including organic, glass, and semiconductor-based substrates that allow for 2.5D or 3D integration of chips and devices. Metal-core substrates are a new alternative with similar properties to those of semiconductor-based substrates but with the added benefits of higher flexibility and metal ductility. This work comprehensively compares the thermal properties of a novel metal-based substrate, molybdenum, and silicon and fused silica glass substrates in the context of system-on-foil (SoF) integration. A simple electronic technique is used to simulate the heat generated by a typical CPU and to measure the heat dissipation properties of the substrates. The results indicate that molybdenum and silicon are able to effectively dissipate a continuous power density of 2.3 W/mm2 as the surface temperature only increases by ~15 °C. In contrast, the surface temperature of fused silica glass substrates increases by >140 °C for the same applied power. These simple techniques and measurements were validated with infrared camera measurements as well as through finite element analysis via COMSOL simulation. The results validate the use of molybdenum as an advanced packaging substrate and can be used to characterize new substrates and approaches for advanced packaging. [ABSTRACT FROM AUTHOR]

This work investigated the effects of pulsed electric field (PEF) pretreatment, combined with different drying methods, on the quality of dried yams. The results showed that the pretreatment resulted in the formation of large pores in the yam tissues, thereby affecting the rehydration capability and hardness of the dried yam slices. The type of drying method after treatment did not alter the free radical stretching bands of yam. Additionally, the pretreated samples had a higher peak viscosity, through viscosity, final viscosity and break down, alongside lower pasting temperatures, To, Tp, Tc, and △H. Rheological measurements further indicated that all doughs exhibited solid-like behavior to different extents. The pretreatment also decreased the amount of allantoin and polysaccharides in dried yam slices, while negatively influencing their antioxidant activity. Finally, the choice of drying methods significantly affected the quality of the dried yams. In highlighting the effects of PEF pretreatment, combined with different drying methods, on dried yam, the results can help to expand their application within the food industry. [ABSTRACT FROM AUTHOR]

In this paper, the cycloidal pin wheel drive mechanism of the secondary drive component of the rotary vector (RV) reducer is studied. Under the condition of grease lubrication, considering tooth profile modifications and machining errors, we established a three-dimensional load-bearing contact analysis model of a cycloid pinwheel transmission mechanism. We studied the time-varying contact characteristics of the gear teeth and dynamic joint surfaces of the inner and outer races of a crankshaft bearing. Considering the thermal effects, we proposed an analysis model of the lubrication characteristics of cycloid pinwheel transmission mechanisms. We also studied the thermal lubrication properties, such as load de-formation, lubrication film thickness, contact pressure and temperature increase at the lubrication contact area. The accuracy of the model was verified by temperature experiments on the inner raceway of an RV reducer bearing and the evolution law of the dynamic thermal lubrication characteristics of the inner and outer races of the crankshaft bearing, the meshing gear tooth pair and the whole process of single pin tooth meshing were revealed. This study provides an effective method for analyzing the temperature increases of the key joints of RV reducers. [ABSTRACT FROM AUTHOR]

This work evaluates the extraction of anthocyanins from star apple (Chrysophyllum cainito L.) fruit peel as an indicator in smart films that respond to color change at different pH concentrations of 1, 3, 5, 7, and 9. Thermoplastic films (TPS) composed of corn starch and concentrations of 10%, 20%, 30%, 40%, and 50% (w/w) of Chrysophyllum cainito L. peel extract were fabricated for characterization. The FTIR results revealed the characteristic bands of the polymer composed with extract and evidenced the increase of this compound exhibiting an increase in the intensity of the bands. SEM results evidenced the interaction between starch and glycerol, as well as an increase in the growth of clumps as the anthocyanin concentration increased; similar tendency was observed in the thermal analysis. The degradation temperatures and mass loss varied as the amount of anthocyanin contained in the film increased. The evaluation of the response of the films as indicators against various pH's showed saturated color changes as the % anthocyanin contained in the film increased at all pH values evaluated. According to the obtained results, it is concluded that the anthocyanin concentration influences the physicochemical and thermal properties of the films; therefore, TPS/anthocyanin films are potential candidates to be used as pH indicators in the food industry. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of exfoliated structure of Poly-methylmethacrylate/organomontmorillonite nanocomposites by in situ polymerization of Methylmethacrylate monomer as a cost-effective adsorbent for ultrahigh removal of azo dye pollutant from aqueous media. The obtained nanocomposites with different organoclay loading (1–7 mass%) were characterized by XRD, FTIR, DTA, TGA, TEM and SEM. In the XRD results, the observation of small pick shoulders (d001) and almost no reflection in the X-ray diffractrograms indicated, respectively, the establishment of intercalated/exfoliated structures and major exfoliation of OMMT clay into polymer. This observation was supported by TEM microscopy. TGA results revealed improved thermal properties in comparison with the pure polymer. Adsorption parameters such as pH-value, contact time and initial dye concentration were investigated to assess optimum adsorption activity. The adsorption experiments showed that the equilibrium time of adsorption was reached very rapidly. According to the kinetic study, the adsorption process followed pseudo-second-order model. The adsorption capacity is unaffected by variation of solution pH. The high maximum adsorption capacity of PMMA/OMT nanocomposite toward dye was found to be 309.6 mg g−1. Langmuir isotherm was more suitable model to describe the adsorption of dye than Freundlich and Dubinin–Radushkevich models. Thermodynamic study showed that the removal of the azo dye from aqueous solution by PMMA/OMT nanocomposite is endothermic nature, spontaneous and physisorption process. Under three adsorption–desorption cycles, PMMA/OMT nanocomposite had good re-adsorption effect. Thus, PMMA/OMT nanocomposite can be an efficient and recyclable adsorbent for azo dyes. [ABSTRACT FROM AUTHOR]

In this work, we have synthesized the zinc‐aluminum layered double hydroxide (ZnAl LDH) nanostructures using cost‐effective hydrothermal technique. The ZnAl LDH and graphene‐based poly(vinyl alcohol) (PVA) nanocomposites are fabricated. The crystal structure, morphology, thermal, and dielectric properties of pristine PVA and ZnAl LDH and graphene‐based PVA nanocomposites films were investigated using X‐ray diffraction, HR‐transmission electron microscopy, thermo gravimetric analysis, and impedance analyzer. HRTEM analysis reveals the hexagonal nanoplates shape‐like morphology of Zn‐Al layered double hydroxides with an average thickness of 40–50 nm and size of 400–600 nm. High thermal stability was observed from ZnAl LDH and graphene‐reinforced nanocomposite. Enhanced thermal stability of 250°C and low weight loss was observed from ZnAl LDH reinforced PVA‐based nanocomposites compared to pristine PVA. Zn‐Al LDH nanoplates‐graphene‐PVA based nanocomposites showed ultra‐high dielectric constant (ɛ′) of 794 as compared to the ZnAl LDH‐PVA nanocomposites (ɛ′ ~ 334) and pristine PVA sample (ɛ′ ~ 35). Low dielectric loss of 0.27, 0.18, 0.38 was observed for pristine PVA, ZnAl‐LDH‐PVA and ZnAl‐LDH‐graphene‐PVA nanocomposites. The large enhancement of the dielectric constant and thermal stability were discussed in terms of improved crystallinity, interfacial polarization and formation of nanodipoles in the matrix. This study reveals a significant role of LDH‐graphene‐based hybrid nanocomposites in optoelectronics, energy storage, sensors, energy conversion and thermally stable devices. Highlights: Growth of highly crystalline zinc‐aluminum layered double hydroxide nanostructures.Improved thermal stability for Zn‐Al LDH‐graphene‐PVA nanocomposites.High thermal stability from ZnAl LDH‐based PVA nanocomposites.Ultra‐high dielectric constant of 794 is observed from Zn‐Al LDH nanoplates‐graphene‐nanocomposites. [ABSTRACT FROM AUTHOR]

Abstract Prototype development nowadays can rarely be imagined without 3D printing. In the fast‐moving electronics industry, 3D printing is a good way to react quickly to changing developments, for example, when it comes to heat sinks made of thermally conductive material. 3D printing of thermally conducting plastics, which are also electrically insulating, is an ideal candidate for the rapid generation of heat sink. Nevertheless, 3D printing also shows some drawbacks in regard to properties of the printed parts, as porosities or layer adhesion, emerging from layer deposition in the process. Therefore, the aim of this work was to investigate the influence of the orientation of fillers on the thermal conductivity of filled polylactic acid (PLA). PLA was filled with amounts of 15–45 wt.% of boron nitride and aluminum granules and printed into heat sinks in two different orientations to investigate this influence on the thermal conductivity. The printed heat sinks were then placed on a heated aluminum block and the thermal transport was examined with an infrared camera. It could be shown that especially with platelet‐shaped fillers such as boron nitride, the orientation of these in the test specimen has a large influence on the thermal conductivity. Highlights 3D printing of thermally conductive heat sinks Thermal characterization of 3D printed heat sinks Computer tomography scans of heat sinks to evaluate the porosity

Hydrogen bond liquid crystals derived binary mixtures are formed between methyl malonic acid (MM) and p-n heptyloxy benzoic acid (7BAO) abbreviated as MM + 7BAO & p-n dodecyloxy (12BAO) benzoic acid abbreviated as MM + 12BAO. Five binary mixtures are obtained as the molar proportion of the precursor mesogens that varies in odd steps from 0.1 to 0.9. Spectral, optical and thermal investigations of the five binary mixtures are carried out thoroughly for analyzing the mesogenic behaviors that apt the binary mixtures for appropriate applicational utility. [ABSTRACT FROM AUTHOR]

The emergence of additive manufacturing has enabled scientists to efficiently construct complex geometric forms, facilitating the creation of robust structures with enhanced resistance to external forces. Fused filament fabrication (FFF) enables the attainment of personalization, enhanced design flexibility, waste reduction, expedited prototyping, and the generation of intricate profiles. In this study, an impact test was conducted to measure the energy absorption of polymer composites fabricated through fused filament deposition. Specifically, the composites investigated were poly-lactic acid reinforced with multi-walled carbon nanotubes, carbon fibers, and graphene. The study examined the effects of different infill patterns and infill densities on the energy absorption capabilities of these composites. The utilization of a gyroid infill pattern with a 100% infill density has been found to demonstrate the highest level of energy absorption in the context of graphene-reinforced poly-lactic acid. In order to examine the relationship between the given process parameters and the energy-absorbing behavior, an analysis of variance using Taguchi's approach is employed on the impact test findings. The examination of fractured surfaces using scanning electron microscopy (SEM) unveiled several types of voids, exhibiting enhanced interlayer adhesion in distinct composite materials. The thermal characteristics of the composite material were determined by the utilization of differential scanning calorimetry (DSC) analysis. The experimental results demonstrate that polymer composites have future potential to be employed in automotive parts that necessitate high impact resistance, such as the fabrication of bumpers and body panels. [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]

This article describes the use of microwave irradiation in the synthesis of bis(cyclo carbonate) compounds (BCCs) in bulk (without solvent) from carbon dioxide capture using an epoxidized compound—a commercial epoxy resin—and compares this process to the conventional method. CO2 cycloaddition to epoxides is an ecological and efficient method for the formation of bis(cyclic carbonates). Moreover, the introduction of gas into the reaction mixture was carried out at atmospheric pressure with a controlled flow rate, which is advantageous from an economic point of view. Progressive structural changes and the presence of characteristic chemical groups were monitored using attenuated total reflectance infrared spectroscopy with Fourier transform. The obtained crude products were purified to obtain three fractions, which were subjected to detailed structural analysis using FT-IR and 13CNMR. The formation of the main product with two cyclic carbonates was confirmed. The presence of monomers, dimers and trimers in individual fractions as well as their thermal stability were determined, and the molecular masses in individual fractions were determined using gel permeation chromatography (GPC). [ABSTRACT FROM AUTHOR]

The structural and thermal characterization of milled wood lignin (MWL) prepared from bamboo (Phyllostachys pubescens) grown in Korea was investigated, and the results were compared with bamboo MWLs from other studies. The C9 formula of the bamboo MWL was C9H7.76O3.23N0.02 (OCH3)1.41. The Mw and Mn of MWL were 13,000 and 4400 Da, respectively, which resulted in a polydispersity index (PDI) of 3.0. The PDI of the prepared MWL was higher than other bamboo MWLs (1.3–2.2), suggesting a broader molecular weight distribution. The structural features of MWL were elucidated using FT-IR spectroscopy and NMR techniques (1H, 13C, HSQC, 31P NMR), which indicate that MWL is of the HGS-type lignin. The major lignin linkages (β-O-4, β-β, β-5) were not different from other bamboo MWLs. The syringyl/guaiacyl ratio, determined from 1H NMR, was calculated as 0.89. 31P NMR revealed variations in hydroxyl content, with a higher aliphatic hydroxyl content in MWL compared to other bamboo MWLs. Thermal properties were investigated through TGA, DSC, and pyrolysis-GC/MS spectrometry (Py-GC/MS). The DTGmax of MWL under inert conditions was 287 °C, and the Tg of MWL was 159 °C. Py-GC/MS at 675 °C revealed a syringyl, guaiacyl, p-hydroxyphenyl composition of 17:37:47. [ABSTRACT FROM AUTHOR]

Prototype development nowadays can rarely be imagined without 3D printing. In the fast‐moving electronics industry, 3D printing is a good way to react quickly to changing developments, for example, when it comes to heat sinks made of thermally conductive material. 3D printing of thermally conducting plastics, which are also electrically insulating, is an ideal candidate for the rapid generation of heat sink. Nevertheless, 3D printing also shows some drawbacks in regard to properties of the printed parts, as porosities or layer adhesion, emerging from layer deposition in the process. Therefore, the aim of this work was to investigate the influence of the orientation of fillers on the thermal conductivity of filled polylactic acid (PLA). PLA was filled with amounts of 15–45 wt.% of boron nitride and aluminum granules and printed into heat sinks in two different orientations to investigate this influence on the thermal conductivity. The printed heat sinks were then placed on a heated aluminum block and the thermal transport was examined with an infrared camera. It could be shown that especially with platelet‐shaped fillers such as boron nitride, the orientation of these in the test specimen has a large influence on the thermal conductivity. Highlights: 3D printing of thermally conductive heat sinksThermal characterization of 3D printed heat sinksComputer tomography scans of heat sinks to evaluate the porosity [ABSTRACT FROM AUTHOR]

Human thermal comfort within various environmental conditions is of paramount importance in a wide range of industries, including clothing design, indoor climate control, and occupational safety. Researchers are always in search the sophisticated tools and techniques that simulate the thermal regulation of human body under different environmental conditions. The present research aims to present a precise methodology for the simulation of clothed thermal manikin in controlled environmental conditions. A comprehensive method is recommended that consists of the use of 3D body scanning technology, different 2D and 3D CAD as well as thermal simulation software. The results of the simulations are very satisfactory, which are later validated with the wear trials with the help of the same clothed thermal manikin and under the same environmental conditions. The comparative analysis shows some deviations that are discussed thoroughly and the need for further research is highlighted in the papers as well. Furthermore, the present research gives us a digital platform to understand the clothing's thermal comfort and the parameters that affect it with the consideration of the draping behavior of the clothing, microclimate, thermal properties, and surrounding environmental conditions. [ABSTRACT FROM AUTHOR]

The paper presents the results of research on the influence of the components of composition on the physicochemical properties of cross-linked poly(sodium acrylate)/sodium silicate hydrogels. The results of the rheological measurements showed that an increasing share of polyacrylate in the sample causes a shift of the cross-over point towards longer times and improves mechanical properties. In turn, increasing the share of sodium silicate has a positive effect on extending the fire insulation time (I). TG/DSC analysis indicated that if the sample contained more than 50 wt.% of polymer, the thermal decomposition was a three-stage process, while if the sample contained more water glass, the decomposition was two stage. UV-Vis measurements and SEM analysis confirmed, inter alia, that increasing the share of polyacrylate causes improvement of the optical parameters and homogeneity of the tested hydrogels. The presented results suggest that by controlling the share of the main components of the silicate–polymer hydrogels, it is possible to control their mechanical, optical and thermal properties. Multiplication of the layers or increasing their thickness improves their fire-retardant properties. [ABSTRACT FROM AUTHOR]

Nowadays, various types of biocomposites are being developed using different types of natural fibers and polymers to fulfill the requirement for sustainable products. Recently, the addition of fillers in biocomposites has been a useful approach to improve their performance and overwhelm their limitations. The hollow glass microspheres (HGMs) were uniformly distributed into epoxy using a magnetic stirrer and subsequently, a hand lay‐up technique was employed to produce the HGMs/coir/epoxy composites under a static loading condition. In the current study, the effect of varying weight percentages (i.e., 1, 3, and 5) of HGMs on the mechanical, dynamic mechanical, and thermal properties of coir/epoxy composites has been studied. Further, morphological analysis of fractured surfaces of samples was also performed. The results suggested that the addition of HGMs caused a significant improvement in the tensile and impact properties of the composites but could not extensively improve the flexural strength, thermal stability, storage modulus, and loss modulus. There was a significant improvement of 80.5% in tensile strength and 24.7% in impact strength of composites after the addition of 1 wt%. HGMs. Further, tensile and flexural moduli were found to be gradually improved with increased HGMs weight percentages in the composites. Highlights: Development of HGMs/coir/epoxy composites.Addition of HGMs increases tensile and impact strength of coir/epoxy composites.Microstructural analysis of HGMs/coir/epoxy composites. [ABSTRACT FROM AUTHOR]

With respect to the fossil resources shortage, the development of bio-based wood adhesives is an important research topic in wood science. There has been research on using sucrose for bio-based adhesives. However, a high acid catalyst content and a high hot-pressing temperature are required when manufacturing particleboards. In this study, to explore the possibility of p-toluenesulfonic acid (PTSA) as a promising acid catalyst for sucrose-based adhesives, the curing behavior of sucrose with PTSA (Suc-PTSA) was clarified. The thermal analysis results showed that the thermal properties of sucrose decreased significantly with the addition of PTSA. Based on the results of the insoluble matter rate, the optimal mixture ratio and heating conditions were determined to be 95:5 and 180 °C for 10 min, respectively. According to the results of FT−IR, the heat-treated Suc-PTSA contained furan compounds. In the context of the dynamic viscoelasticity, the onset temperature at which the storage modulus (E′) begins to rise was significantly lower than those of the other sucrose-based adhesives. PTSA has the potential to cure sucrose more efficiently and at lower temperatures than previous sucrose-based adhesives, making it a promising acid catalyst for sucrose. [ABSTRACT FROM AUTHOR]

The synthesis of glycopolymers by copolymerising an allyl glucosamine (AG) monomer with co-monomers methyl methacrylate (MMA), acrylonitrile (AN) and 2-hydroxyethyl methacrylate (HEMA) was investigated via free-radical polymerisation of 2,2-azobisisobutyronitrile (AIBN) in dimethylformamide (DMF). Three new copolymers, poly(AG-co-MMA), poly(AG-co-AN) and poly(AG-co-HEMA), were obtained. The chemical structures of the glycopolymers were analysed using 1H-NMR, 13C-NMR and FTIR. The thermal properties and degradation kinetics of the three glycopolymers were examined by thermogravimetric (TG) analysis at different heating rates. The effects of different co-monomers on the copolymerisation yield, thermal properties and biological activities of the resulting glycopolymers were investigated. The activation energies of the decomposition stages were calculated using the Flynn–Wall–Ozawa (FWO) and Kissinger methods. Furthermore, the biological activity of AG monomers and glycopolymers was studied and compared to chitosan. Poly(AG-co-HEMA) had the most significant effect on MCF-7 cell viability, and all glycopolymers have a low toxic effect profile on MCF-7 cell lines. [ABSTRACT FROM AUTHOR]

To understand the transient heat transfer characteristics of nanoporous aerogel insulating composites, solving the inverse heat transfer problem would be crucial for identifying the temperature-dependent thermal properties of composites. In this study, with constructed a forward model to numerically investigate the heat transfer in composites, a deep neural network (DNN) model and a particle swarm optimized deep neural network (PSO-DNN) model are conducted to rapidly estimate the effective temperature-dependent thermal conductivity of the desiccated and moist composites from the temperature response measurements. With the DNN model, the retrieved thermal conductivities for desiccated composites possess low deviation to experimental measurements (<3.2%) and constantly low errors (<5.2%) from 280 K to 1080 K. The precision of the DNN solver could be enhanced by adjusting the hyperparameters of the neural networks using PSO. The retrieved thermal conductivities possess low deviation from experiments (<2.5%) and low relative errors within 1.5%. Furthermore, the robustness of the PSO-DNN solver is discussed when commercial thermocouple measurement errors are considered, within retrieving the thermal properties of desiccated and moist aerogel composites. [ABSTRACT FROM AUTHOR]

This article presents the development of an automated three-point bending testing system using a robot to increase the efficiency and precision of measurements for PLA/TPU polymer blends as implementation high-throughput measurement methods. The system operates continuously and characterizes the flexural properties of PLA/TPU blends with varying TPU concentrations. This study aimed to determine the effect of TPU concentration on the strength and flexural stiffness, surface properties (WCA), thermal properties (TGA, DSC), and microscopic characterization of the studied blends. [ABSTRACT FROM AUTHOR]

This study explores the effect of alkali treatment at ambient (25 °C) and elevated temperatures (100 °C) on the physicochemical, structural, morphological, and thermal properties of Calamus tenuis cane fibers (CTCFs) for the first time. Our purpose is to investigate their potential use as reinforcement in polymer composites, since cane fibers are generally known for their accurate and consistent geometrical orientation. Treatment with 8% (w/v) sodium hydroxide (NaOH) is carried out at ambient temperature and at 100 °C for 4 h. Chemical analysis and Fourier transform IR spectroscopy (FTIR) indicate some removal of non-cellulosic elements from CTCFs during alkali treatment, resulting in increased surface roughness, as confirmed by using SEM micrographs. This removal of non-cellulosic elements leads to an enhancement in the density of the treated CTCFs. Untreated and treated fibers are analyzed for maximum degradation temperature, thermal stability, and kinetic activation energy (Ea) using thermogravimetric analysis (TGA). In particular, Ea was considerably diminished with treatment and temperature. X-ray diffraction (XRD) results show an improved crystallinity index (37.38% to 44.02%) and crystallite size (2.73 nm to 2.98 nm) for fibers treated with 8% NaOH at ambient temperature. In conclusion, a general benefit was achieved by treating CTCFs, though the influence of increasing temperature treatment appears controversial. [ABSTRACT FROM AUTHOR]

Rheological and thermal properties are important parameters to understand the role of the numerous variables involved in manufacturing and to achieve a high‐quality final product. The composites were prepared by compounding polypropylene (PP) with treated (alkaline and silane) oil‐palm empty fruit bunch (EFB) fiber using a twin screw extruder. Generally, regardless of fiber loading, the thermal stability of EFBPP composites was increased after using alkaline and silane‐treated EFB fibers as reinforcement. DSC analysis shows that there is a change in the melting temperature (Tm) and the degree of crystallinity (Xc) values of the EFB composites. The melt flow rate (MFR) of the composites decreased while viscosity increased with an increase in fiber loading. Rheological analysis reveals the composites to have a viscoelastic solid behavior where storage modulus (G') is greater than loss modulus (G"). The composites exhibit predominantly viscous behaviour (G" > G') at lower frequencies, whereas at higher frequencies the composites exhibit elastic behavior (G' > G"). The decrement of complex viscosity (η*) with an increasing angular frequency (ω) shows the materials exhibit shear thinning behavior. The composites also show the ability for regeneration when analyzed using time‐dependent behavior. [ABSTRACT FROM AUTHOR]

A method was proposed for the synthesis of Eu(III) compounds with para-methoxycinnamic acid anions and neutral ligands, starting from the sodium salt of para-methoxycinnamic acid. Using the methods of chemical elemental and thermal analyses and IR spectroscopy, the composition of the complexes and the coordination mode of carboxylate anions were determined. It was found that europium(III) methoxycinnamate with hexamethylphosphotriamide has the highest luminescence intensity. Luminescent polymer materials with synthesized europium(III) methoxycinnamates were obtained. [ABSTRACT FROM AUTHOR]

Simple Summary: Bacteriophage endolysins are specialized enzymes that act like natural antibiotics, breaking down the outer layer of harmful bacteria. One specific endolysin, PlyC, has shown promising abilities in effectively combating streptococcal bacteria. However, before considering PlyC as a long-term treatment option, we must comprehend its behavior under various conditions. This study investigated PlyC's stability under different temperatures to assess its potential as a therapeutic option. The findings revealed that when exposed to 46 °C, PlyC's structure starts to unfold, rendering it inactive. Particularly, the PlyCA region containing two enzymatic domains is highly sensitive to temperature changes, leading to PlyC's overall inactivity. In contrast, PlyCB, the part responsible for binding to bacterial surfaces, can endure higher temperatures: up to about 75 °C. Understanding the behavior of PlyC, along with its PlyCA and PlyCB domains, is crucial for its future development as a highly effective treatment against bacterial infections. Bacteriophage endolysins degrade the bacterial peptidoglycan and are considered enzymatic alternatives to small-molecule antibiotics. In particular, the multimeric streptococcal endolysin PlyC has appealing antibacterial properties. However, a comprehensive thermal analysis of PlyC is lacking, which is necessary for evaluating its long-term stability and downstream therapeutic potential. Biochemical and kinetic-based methods were used in combination with differential scanning calorimetry to investigate the structural, kinetic, and thermodynamic stability of PlyC and its various subunits and domains. The PlyC holoenzyme structure is irreversibly compromised due to partial unfolding and aggregation at 46 °C. Unfolding of the catalytic subunit, PlyCA, instigates this event, resulting in the kinetic inactivation of the endolysin. In contrast to PlyCA, the PlyCB octamer (the cell wall-binding domain) is thermostable, denaturing at ~75 °C. The isolation of PlyCA or PlyCB alone altered their thermal properties. Contrary to the holoenzyme, PlyCA alone unfolds uncooperatively and is thermodynamically destabilized, whereas the PlyCB octamer reversibly dissociates into monomers and forms an intermediate state at 74 °C in phosphate-buffered saline with each subunit subsequently denaturing at 92 °C. Adding folded PlyCA to an intermediate state PlyCB, followed by cooling, allowed for in vitro reconstitution of the active holoenzyme. [ABSTRACT FROM AUTHOR]

Two azo dye ligands, bearing different substituents (chlorine atom or methoxy group) in the para‐position of the phenyl ring, were employed for the synthesis of two Cu(II) chelates. Full structural affirmation of complexes was assessed. X‐ray diffraction measurements revealed that the coordination geometry for Cu atoms in both complexes is square‐pyramidal with a ligand:metal ratio of 2:1 where dyes behave as monobasic bidentate ligands. Thermogravimetric analyses of the complexes and their starting dyes were performed to study their thermal stabilities and decomposition behavior confirming the thermal stability of both dyes and complexes. Antioxidative activity of the complexes has been assigned and compared with their parent ligands revealing that the presence of the electron–donor, methoxy group, in the phenyl ring, in both dye and complex, is responsible for the activity (IC50 values of 1.54 for the dye and 1.30 mM for the complex). It should be stated that the complexation of the methoxy‐substituted dye leads to enhanced antioxidative activity concurrent to a standard antioxidant molecule of ascorbic acid, making this molecule a promising antioxidant agent. Docking study with vascular endothelial growth factor receptor 2 and Aurora kinase A proteins indicate that complexes exhibit higher binding affinities to proteins than the starting ligand dyes. The most promising structure exhibiting the best docking potential toward both proteins is the complex‐bearing methoxy group. The presented results represent a promising start for further investigations of these compounds as potential therapeutic candidates for the treatment of various types of cancer. [ABSTRACT FROM AUTHOR]

Bio-based interpenetrating polymer networks (IPNs) with tunable thermal and mechanical properties were prepared by bio-based polyurethane (PU) and epoxy resin (EP) derived from plant oils. The cure reaction, dynamic mechanical properties, thermal stability, mechanical performance and morphology of bio-based PU/EP IPNs were characterized by Fourier transform infrared spectroscopy, dynamic mechanical analysis, thermogravimetry, universal test machine and scanning electron microscopy. Dynamic modulus, glass transition temperature, thermal stability and tensile strength of bio-based EP/PU IPNs decreased in the content of soybean oil-based PU prepolymers. However, the damping properties of bio-based EP/PU IPNs increased in the content of soybean oil-based PU prepolymers. The elongation at break of bio-based EP/PU IPNs was greatly higher than that of the plant oil-based EP. The elongation at break of the bio-based EP/PU IPN containing 20% soybean oil-based PU prepolymer was fourfold higher than that of the plant oil-based EP. Soybean oil-based PU prepolymer significantly improved the damping properties and the elongation at break of the plant oil-based EP. By adjusting the mass ratio of the plant oil-based EP to the soybean oil-based PU, the glass transition temperature, damping and mechanical properties of bio-based PU/EP IPNs can be optimized. [ABSTRACT FROM AUTHOR]

The properties of unconventional blends of crystallizable and thermo-cross-linkable polychloroprene (CR) with polybutadiene (BR) were investigated in this study. The compositions were prepared using the method of reactive processing and cross-linking in the presence of nano-sized zinc (nZn). The purpose of the research was to assess the efficacy of nano-zinc as a curing agent of polychloroprene and polybutadiene (CR/BR) composites and to obtain rubber goods characterized by increased flame resistance. The blends were filled with nano-silica (aerosil) and fillers of natural origin (chalcedonite or silitin). The cross-linking process was characterized by determining the kinetics curves, the equilibrium swelling, and the Mooney–Rivlin elasticity constants. The morphology of the vulcanizate surface was specified by scanning electron microscopy (SEM). The dynamic and mechanical properties, flammability, and toxicity of gaseous substances involved in thermal decomposition were determined. Mass changes and thermal effects were studied using simultaneous thermal analysis (STA). It was confirmed that nano-zinc is an efficient curing agent for the polychloroprene and polybutadiene compositions, with a satisfactory degree of cross-linking (αc = 0.10, CRI = 4.11 min−1), good mechanical strength (TSb = 5 MPa), satisfactory tear resistance (Ts = 2.9 N/mm), and very high flame resistance (OI = 30%, HRRmax = 283 kW/m2). Filled products could be used as non-combustible materials, confirming the low fire hazard (1/tflashover = 3.5–6.4 kW/m2∙s). The most effective filler of the tested composites was nano-sized silica. [ABSTRACT FROM AUTHOR]

In this study, the durability of a new polymer carbon fiber-reinforced epoxy resin used to produce composite material in the aerospace field is investigated through analysis of the corrosion phenomena occurring at the microscopic scale, and the related infrared spectra and thermal properties. It is found that light and heat can contribute to the aging process. In particular, the longitudinal tensile strength displays a non-monotonic trend, i.e., it first increases and then decreases over time. By contrast, the longitudinal compressive and inter-laminar shear strengths do not show significant changes. It is also shown that the inter-laminar shear strength of carbon fiber/epoxy resin composites with inter-laminar hybrid structure is better than that of pure carbon fiber materials. The related resistance to corrosion can be improved by more than 41%. [ABSTRACT FROM AUTHOR]

Numerous scenarios of direct contact between electronic components and skin appear in wearable electronic devices. As the "second skin" that lies next to the biological skin of the human body, flexible wearable devices need to be equipped with thermal protection. However, the use of flexible phase change materials (PCMs) for wearable devices remains a challenge due to their low thermal conductivity, weakened mechanical strength, and liquid leakage. Herein, we developed a multilayered polyimide (PI) composite film integrating stable latent heat absorption, high thermal conductivity, and enhanced mechanical strength. This single piece of material achieved more prominent hotspot protection than traditional foams. The in-plane thermal conductivity of the resultant substrate layer is up to 2.655 W/(m K), which provides a fast response and in-plane dissipation for heat flow. The deliberately arranged interlayer of the material significantly improved the tensile strength (37.6 MPa) of the composite film, representing 128.9% greater strength than that of a bilayer film without a dense layer. The top layer with abundant pores provides reversibly latent heat storing and releasing function after being well infiltrated with paraffin wax. The resulting synergistic effect between three functional layers shows superb heat-suppressing performance in the thickness direction in both thermal shock-resistant tests and simulation results. Impressively, the maximum temperature drop reached 40.2°C compared with the pure PI film. The heating time was delayed by 12 s, providing sufficient warning time for human emergency response. This strategy can potentially pave the way for the design and fabrication of multifunctional films for wearable electronics in thermal protection applications. [ABSTRACT FROM AUTHOR]

Polyolefin copolymers have been an important commercial product since their invention. Hence, it is crucial to study their co‐ and terpolymers due to their extensive use. In this paper, in situ synthesis of ethylene‐propylene (EP) copolymer, its terpolymer with styrene, and composites with nickel‐chromium (NiCr) layered double hydroxide (LDH) has been reported along with their thermal properties. Styrene had a significant impact on the activity, increasing the yield by 195% and 235% with an addition of 0.5 and 1.0 mL styrene, respectively, compared to neat EP. The crystallinity, melting temperature, and thermal stability decreased due to styrene; nevertheless, it performed better compared to a similar work of terpolymer where α‐olefin was the third monomer. The incorporation of NiCr LDH as a drop‐in filler during in situ polymerization affected adversely the thermal stability of the terpolymer. However, the ultrasonication treatment improved the thermal stability of the final product. [ABSTRACT FROM AUTHOR]

As potential precursors for the synthesis of fluoroperovskites, a family of heavy alkali metal (MI = K, Cs) fluorinated β-diketonates were prepared and characterized by elemental analysis, IR, and powder-XRD. The crystal structures of the new six complexes, MI(β-dikF)(H2O)X, X = 0 or 1, were also determined. The structural diversity of this poorly explored class of complexes was discussed, including the preferred types of cation polyhedra and the ligand coordination modes, and the thermal properties of the metal β-diketonates were studied by TG–DTA in an inert (He) atmosphere. The data obtained allowed us to reveal the effect of the metal cation and the terminal substituent on the structural and thermal features of this family of complexes. [ABSTRACT FROM AUTHOR]

In this paper, the authors present a comparative analysis of the thermomechanical properties of plastics intended for machining before and after the annealing process. The research included the dynamic properties, thermal analysis and a study of the surface after machining. The dynamic properties were tested using the DMTA method. The characteristics of changes in the value of the storage modulus E' and the tangent of the mechanical loss angle tgδ depending on the temperature and vibration frequency were determined. The thermal properties were tested using the DSC method, and a comparative analysis of the roughness parameters of the tested materials obtained from the profilometer was carried out. The presented studies indicate the extent of the impact of the annealing process on the machinability of structural polymer materials, taking into account the analysis of changes in the thermomechanical properties of the tested materials. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the mechanical and thermal properties of composite pipes based on epoxy resin and glass fibers produced by filament winding (FW) technology. Epoxy resins are widely used polymers in FW composite structures. The thermal characterization of the neat epoxy resin, curing, and post-curing characteristics for the determination of polymerization and glass transition temperature was performed, which is important for the mechanical properties of polymer composite pipes. In the present work, the applicability of the full factorial experimental design in predicting the hoop tensile and compressive strengths of glass fiber/epoxy resin composite pipes was investigated. The composite pipes in accordance with the 23 full factorial experimental design by using of three parameters and two levels of variation were prepared. The winding speed of the composites was taken to be the first factor, the second was the fiber tension, and the third was winding angle. To approximate the response, i.e., the mechanical properties of the composite pipes within the study domain, the first-order linear model with the interaction was used. The influence of each individual factor to the response function was established, as well as the influence of the interaction of the two and three factors. Additionally, those results were completed with the thermal characterization of the polymer composite pipes. From received results from mechanical and thermal characterization, it was concluded that the properties of composite specimens were highly affected by the analyzed parameters in filament winding technology. It was found that the estimated first-degree regression equation with the interaction gave a very good approximation of the experimental results of the hoop tensile and the compressive strengths of composite pipes within the study domain. [ABSTRACT FROM AUTHOR]

In this article, considering the coupled interaction of heat, stress, material wear, and wheel–rail force transmission in the disc-braking process, a complex multifield coupled method was proposed to study thermal mechanical properties and contact state of brake discs. First, a coupled dynamic model of train, track, and brake gear was established to analyze the force transmission between brake friction pairs and wheel–rail system. Based on the coupled dynamics simulation results, a thermomechanical wear coupled model of the friction pair was established. It is found that the track irregularity results in vertical relative displacements with a range of (–2.6 mm, 2.8 mm) and makes the maximum brake force increase to 24.1 kN. As a comparison, brake bench tests without wheel–rail interaction were carried out. This showed that there was no vertical relative displacement between the friction pair, and the braking force had a stable value of 22.5 kN. The simulation results of the brake disc temperature distribution, and the friction pair contact state are consistent with the bench test results. In addition, different thermal simulation methods of the brake disc were used to verify the validity of the complex multifield coupled simulation results. [ABSTRACT FROM AUTHOR]

Chemical, structural, and thermal properties of recovered nematic Liquid Crystal (LC) mixtures were investigated by applying several analytical techniques. A large quantity (65,700) of End-Of-Life (EOL) Liquid Crystal Display (LCD) screens were used to extract these LC blends. The studied EOL-LCD screens were heterogeneous in nature, particularly due to their different brands, production years, and dimensions. The collected TV and computer screens, as well as tablets, presented an average diagonal size of 24 inches. Chemical characterization revealed that the recovered compounds present typical chemical structures of LC molecules by the simultaneous presence of aliphatic chains and aromatic and polar groups. POM observations of these samples exhibited Schlieren and marble-like textures at room temperature, which are typical of nematic LCs. Moreover, thermal characterization and thermo-optical analysis showed that these LC mixtures displayed a broad nematic phase between −90 °C and +70 °C. [ABSTRACT FROM AUTHOR]

Bagasse is a waste used as a new material for foam polymer composites as reinforcement. This waste is quite a lot and has not been processed properly to become new material. This waste is adopted as ordinary organic fertilizer, incinerated, or disposed of. For that reason, it needs further research investigation. Due to its advantages, further investigation into the best composition is needed to achieve a tough composite material. It is a lightweight material with high economic value and can be used to overcome environmental problems. Therefore, this research obtains the mechanical properties and thermal analysis of the composite polymer foam reinforced with bagasse fibers. Part of the matrix is a thermoset polymer polyurethane (BQTN 157), and the reinforcement part is bagasse fiber. Bagasse was local waste from traders around Langsa City in Indonesia. The bagasse waste was processed into the fiber. The bagasse composition on a percentage weight ratio. They were mixed with resin and foam ingredients, blowing agent, and catalyst and poured into casting pattern composite material. A mesh of bagasse fiber was the size of 80. Thermogravimetric Analysis has made All specimens that need a tensile test to obtain the material's strength and thermal stability. The result has found that the specimen of polymeric foam composite material with 5% bagasse fiber was obtained based on the results. The tensile strength values are 19.5 MPa. A thermal stability condition changes temperature between 39.95°C - 516.55°C. [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]

This study focuses on the thermal properties and structural features of blends consisting of thermoplastic starch (TPS) and poly(ethylene-co-methacrylic acid) copolymer (EMAA) or its ionomer form (EMAA-54Na). The aim is to investigate how carboxylate functional groups of the ionomer form intervene in blends compatibility at the interface of the two materials and how this impacts their properties. Two series of blends (TPS/EMAA and TPS/EMAA-54Na) were produced with an internal mixer, with TPS compositions between 5 and 90 wt%. Thermogravimetry shows two main weight losses, indicating that TPS and the two copolymers are primarily immiscible. However, a small weight loss existing at intermediate degradation temperature between those of the two pristine components reveals specific interactions at the interface. At a mesoscale level, scanning electron microscopy confirmed thermogravimetry results and showed a two-phase domain morphology, with a phase inversion at around 80 wt% TPS, but also revealed a different surface appearance evolution between the two series. Fourier-transformed infrared spectroscopy analysis also revealed discrepancies in fingerprint between the two series of blends, analysed in terms of additional interactions in TPS/EMAA-54Na coming from the supplementary sodium neutralized carboxylate functions of the ionomer. [ABSTRACT FROM AUTHOR]

The crystal structure of the rare mineral caryochroite is determined for the first time using X-ray diffractometry and electron microdiffraction data. The new idealized crystal formula of the mineral is [Na(Sr0.5Ca0.5)Mg]3[Fe Mn()]10(Ti2Si12)O37(OH)14(Н2О)3. The parameters of the monoclinic unit cell refined by the least square method are a 16.550(3), b 5.281(2), c 24.25(3) Å, β 93.0°, Z = 2, space group P2/n. The crystal structure of caryochroite is a new type of Ti–Si lattice responsible for the large structural channels, which are able to enclose the exchange cations and a high amount of water components (OH groups and H2O molecules). [ABSTRACT FROM AUTHOR]

The 2-oxo-1,2-dihydroquinolin-8-yl 4-chlorobenzoate was synthesized in good yield using a triethylamine-mediated O-acylation reaction between 8-hydroxyquinolin-2(1H)-one and 4-chlorobenzoyl chloride in acetonitrile at room temperature. This methodology is notable for its clean reaction profile and straightforward procedure. The 2-oxoquinoline derivative was characterized using spectroscopic, spectrometric, and thermal analyses, enabling a comprehensive understanding of its molecular structure and thermal properties. [ABSTRACT FROM AUTHOR]