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This study investigates the effect of positive temperature coefficient (PTC) fillers, i.e., barium strontium titanate (BST‐60) and nano hexagonal boron nitride (h‐BN) fillers, on thermal and dielectric insulation properties of epoxy (EP). The electrical resistivity, DC breakdown strength, space charge, thermal conductivity, thermogravimetric analysis, and glass transition temperature (Tg) of EP composites were measured. Results indicate that, below curie temperature, the EP composites containing 0.5 and 1 wt% of BST and 5 wt% of h‐BN have superior electrical resistivity, breakdown strength, and thermal conductivity. However, above curie temperature, the EP composites containing 2 and 2.5 wt% of BST and 5 wt% of h‐BN have superior insulation properties than the pure EP and other composites. While the thermal properties of EP improve with an increase in h‐BN loading to 10 wt%, its dielectric properties are slightly compromised due to the presence of tiny defects in the composite material. It is hypothesized that the BST‐60 suppresses the negative temperature coefficient effect (NTC) of EP by regulating the electrical resistivity above the curie point, whereas nano h‐BN enhances the thermal conductivity of EP by constructing a heat dissipation path. The proposed mechanism for charge dynamics along with heat conduction‐dissipation explains the fillers' behavior at different temperatures. Highlights: Analysis of epoxy composites with polydopamine‐modified BST and h‐BN fillers.PTC fillers are used to mitigate the negative temperature effect of epoxy.Optimal fillers wt% improves dielectric and thermal properties.This study shows that optimized epoxy composites can be used for packaging. [ABSTRACT FROM AUTHOR]

The use of hybrid reinforcement in polymer composites has been getting attention due to its potential for weight and cost reduction while achieving improved design flexibility for mechanical and thermal properties. In this study, an interply hybridization of epoxy laminates was performed using layers of solid and hollow glass fibers. The structural and thermal performance of the resulting hybrid vascular composites was investigated. All composite parts were manufactured using vacuum‐assisted resin transfer molding (VARTM), following an interply hybridization plan for the stacking sequence of hollow and solid fiber layers. An expected decrease in flexural properties and thermal conductivity was observed for the laminates with completely hollow fibers. On the other hand, hybridization had a positive effect on the laminate properties. It was shown that hybrid vascular composites could be manufactured without a significant reduction in mechanical and thermal performance by a judicious hybridization plan. The optimum hybridization of the laminate achieved a 3.1% increase in the specific flexural strength and a 5.3% decrease in thermal conductivity while containing a vascular network that can be used for active thermal control. Highlights: A vascular interply composite structure consisting of hollow and solid fibers was manufactured and characterized for the first time.The I4 composite, vascularized through the middle layers of the laminate, has almost as much flexural strength as solid composite and much more specific flexural strength.The thermal conductivity of the I4 composite is almost as much as that of the solid composite.Functional composites for thermal management and smart applications can be manufactured using hollow fibers without sacrificing flexural strength and thermal conductivity with interply vascularization. [ABSTRACT FROM AUTHOR]

In this study, the impact of incorporating cellulose nanofibrils (CNF) and carboxylated organo‐montmorillonite (OMMT), separately or in combination, into a UV‐curable wood coating was evaluated for performance enhancement. This study investigated the influence of nanoparticle loading percentage on the mechanical properties and thermal behavior of the coating, as well as the surface properties of digitally printed decorative wood‐based panels. The results indicated that the addition of CNF or OMMT increased the viscosity of the polymer solutions. Although CNF randomly oriented within the matrices, OMMT adhered to the surface of the polymer matrix. Chemical crosslinking was observed between CNF/OMMT and the coating. The addition of CNF and OMMT improved the thermal stability of the neat UV curing coating. The tensile strength of nanocomposite films with a 6 wt% loading of CNF increased significantly from 7.63 MPa to 12.73 MPa compared to pure films. The reinforcing effect of CNF on the tensile performance was significantly better than that of OMMT. Adding CNF to the matte coating slightly improved the clarity of the printed decorative panels. When CNF and OMMT were added together in the coating, there was a synergistic enhancement in the low gloss and high pencil hardness of the panels. Highlights: Both CNF and OMMT were chosen to achieve performance improvementsA simple filling method was adopted for preparation of reinforced coatingThe nanocomposite films exhibited fine thermal and mechanical propertiesThe better integrated property was obtained from the C + CNF3 + OMMT0.8 sampleThe physicochemical interaction of nanofiller with polymer molecule existed [ABSTRACT FROM AUTHOR]

This study discussed the impact of pectinase treatment on the properties of starch/PBAT composite, using two types of plant fibers such as coconut coir and bamboo fibers. The fibers underwent pretreatment with pectinase assisted by ultrasonics, and the composite was subsequently produced through hot pressing. The research focused on evaluating the thermal properties, mechanical properties, moisture absorption properties, and microstructure of the resulting composites. The findings revealed that the inclusion of pectinase‐treated plant fibers significantly enhanced the composite's strength. In particular, the bending strength of the composite with 15 wt% bamboo fibers exhibited the highest improvement, registering a 65% increase compared to the composite without added fibers. Additionally, the linear expansion coefficient of the plant fiber composite treated with pectinase was notably lower than that without added fibers. Among these, the linear expansion coefficient of the 15 wt% coir fiber composite decreased by 73.4% in the temperature range of 40–80°C compared to the composite without added fibers. The observed effects were attributed to the pectinase treatment, which proved effective in disrupting the network structure of cell walls, eliminating pectin components from fibers, and facilitating enhanced interaction between the fillers and the polymer matrix. Highlights: The inclusion of fibers significantly enhanced the composite's strength.10 wt% of bamboo fibers had a greater impact on the composite's strength than coir fiber.The linear expansion coefficient of the plant fiber composite decreased.The composite with 5 wt% bamboo fiber demonstrated excellent moisture resistance.The pectinase treatment enhanced interaction between fillers and matrix. [ABSTRACT FROM AUTHOR]

Epoxy resins (EPs) are highly coveted as insulating materials for engineering applications. However, their limited mechanical properties and inadequate thermal conductivity at cryogenic temperatures significantly restrict their range of applications. Herein, a novel approach was introduced for crafting EP composites infused with boron nitride (BN) using hyperbranched polymer (HBP) grafting. The resulting HBP‐BN was uniformly dispersed within the EP and securely bonded to the matrix through robust chemical interactions, significantly improving the property enhancement efficiency of HBP‐BN on EP. Thus, the mechanical strength of EP/HBP‐BN composites was significantly enhanced, with maximum tensile and impact strengths achieved at 6 and 4 wt% HBP‐BN content. These values exceeded those of pure EP by 47% and 22% at room temperature (RT) and increased even more substantially to 72% and 135% at 77 K. Moreover, the composite demonstrated a remarkable 430% improvement in thermal conductivity, reaching 1.1627 W·m−1·K−1, when the HBP‐BN content reached 40 wt%. Simultaneously, EP/HBP‐BN composites exhibit low dielectric permittivity and high volume resistivity, signifying exceptional electrical insulation properties. HBP‐BN substantially enhances the cryogenic properties of EP composites, offering an efficient pathway for the utilization of EPs in engineering applications. Highlights: A novel method to enhance the cryogenic properties of EP was introduced.HBP‐BN significantly improves the cryogenic properties in EP composites.The composites are of significant interest for various engineering applications. [ABSTRACT FROM AUTHOR]

Highlights This study aims to enhance the properties of biodegradable plastics by blending poly(lactic acid) (PLA) as well as poly(butylene succinate) (PBS) with silicon carbide (SiC). SiC content was varied from 10 to 40 phr using an internal mixer, maintaining a 90/10 wt% ratio of PLA/PBS as the matrix. The investigation covered mechanical, thermal properties, chemical structure, and composite morphology. The morphological analysis confirmed even dispersion of SiC within the PLA/PBS matrix, possibly due to improved compatibility via a silane coupling treatment. This resulted in the maximum Young's modulus and impact strength with 40 phr SiC, showing a 40% and 76% enhancement, respectively, compared to pure PLA. Concerning thermal properties, SiC addition influenced the mobility of PLA/PBS molecular chains and crystalline structure, leading to an increase in Tg with higher SiC fractions. However, ΔHm of PLA, PBS, and Xc,PLA decreased, which corresponds to reduced viscosity in the PLA/PBS blend and increased mobility with higher SiC content, as indicated by the elevated MFI value. Young's modulus increased by 40% and impact strength by 76% than pure PLA. Even SiC dispersion in PLA/PBS, possibly aided by silane coupling. SiC alters chain mobility, boosts crystalline structure, raising Tg. ΔHm and Xc,PLA reduced, suggests reduced viscosity in PLA/PBS at more SiC. Elevated MFI value shows increased chain mobility in PLA/PBS blend at more SiC. [ABSTRACT FROM AUTHOR]

To date, the thermal and electrical properties of three‐phase ceramics containing a boride phase, silicon carbide, and boron carbide have not been studied in detail. Further, the effect of the source of the boride powder has also not been investigated. This study produced three‐phase ceramics containing titanium diboride, silicon carbide, and boron carbide using three different TiB2 sources: commercial powder, TiB2 synthesized by boro/carbothermal reduction, or (Ti,Cr)B2 synthesized by boro/carbothermal reduction to address the effect of the TiB2 source. Ceramics containing synthesized TiB2 or (Ti,Cr)B2 reached >99% relative density, while the ceramic produced from commercial powder reached ∼93% relative density. The addition of Cr reduced both the thermal and electrical conductivities, but had little effect on the Vickers hardness. The (Ti,Cr)B2–SiC–B4C ceramic had a thermal conductivity of ∼33 W/m K, an electrical conductivity of ∼105 S/m, and a hardness of ∼61 GPa at 0.49 N. The highest hardness of ∼66 GPa at a load of 0.49 N was for the TiB2–SiC–B4C ceramic made with synthesized TiB2 powder. [ABSTRACT FROM AUTHOR]

Highlights The development of innovative composite materials through the amalgamation of thermoplastic polyurethane (TPU) with bismuth sodium titanate (BNT) and carbon nanotube (CNT) fillers was investigated. Before the composite fabrication, the fillers' surfaces were treated to enhance their compatibility with the TPU matrix. Hybrid fillers of BNT and CNTs were fabricated by mixing the two types of filler particles through ball milling and subsequently annealing the mixture at 250°C. Melt‐blending and injection molding were utilized to synthesize the composites at 210°C processing temperature. The prepared composites showed significantly enhanced thermal conductivity, dielectric constant, thermal stability, and thermomechanical properties compared with the neat TPU matrix. For instance, the dielectric constant was enhanced by 340% upon the inclusion of 40 wt.% BNT and CNT fillers compared to the neat TPU matrix (40CBNT‐TPU has 13.2). In particular, the inclusion of BNT‐CNT particles in the TPU matrix improved the thermal conductivity of the TPU matrix by 1180% tremendously as compared to neat TPU (40CBNT‐TPU has 2.6 W/(m.K)). Crystalline bismuth sodium titanate (BNT) is fabricated. Degradation of 8 wt.% of the IPDI‐treated BNT proves surface treatment. Dielectric constant (DC) improved by 340% compared to neat TPU. Thermal conductivity (TC) enhanced 11.4 times compared to neat TPU. Improvement in TC and DC will make it applicable in electronic materials. [ABSTRACT FROM AUTHOR]

Epoxy film adhesives are typically used in different industries. However, these adhesives suffer from brittleness, low flexibility, and thermal stability problems. In this research, phenolic resin (Novolac) and poly (butyl acrylate‐block‐styrene) were used in the formulation of epoxy film adhesive (Diglycidyl ether bisphenol A) to increase thermal stability and adhesion strength and as the toughening agent, respectively. Alumina nanoparticles were also employed to enhance the mechanical properties. The influence of block copolymer and alumina nano particles was also assessed on the mechanical and thermal properties of epoxy‐based film adhesives. The investigation of the mechanical properties of dumbbell‐shaped samples and adhesion strength of the Al‐Al bonded joints were evaluated by tensile, lap shear, and T‐peel tests. The thermal stability of the optimal samples was assessed by thermogravimetry analysis (TGA). SEM analysis was also utilized to study the toughening mechanism. Tensile test of the dumbbell‐shaped samples indicated that the incorporation of 2.5 phr block copolymer and 2 phr alumina nanoparticles enhanced the toughness to 250%. The shear and peel strengths of this sample also exhibited 51% and 76% increase, respectively, showing a remarkable synergistic effect. On the other hand, TGA results revealed that the incorporation of block copolymer improved the thermal stability of the adhesive matrix. The copresence of these two materials also showed a considerable synergistic effect on the thermal stability. The SEM results were also in line with the results of mechanical tests as the crack deviation, crack pinning, and debonding were the most important mechanisms of toughening. Highlights: A new platform was developed for designing epoxy films adhesives with high mechanical, adhesion, and thermal properties.The hybrid of butyl acrylate block styrene copolymer, phenolic resin, and alumina nanoparticles showed synergistic effects on the lap shear and T‐peel strength.The greatest improvement in toughness was related to the epoxy adhesive containing 2.5 phr block copolymer and 2 phr alumina nanoparticles.Analysis of the fracture surface showed that by using hybrid of nanoparticles and block copolymers in the epoxy film adhesive formulation, the cohesive failure occurred.The use of hybrid additives in film adhesive formulations enlightened manufacture of adhesives for future studies on adhesive formulations. [ABSTRACT FROM AUTHOR]

Thermally conductive polymeric composites with low dielectric constant are highly promising for the packaging materials in the field of modern communication. Therefore, the synergistic improvement of low dielectric constant and high thermal conductivity has become a current research hotspot. In this work, we propose a one‐step alkylation of boron nitride nanosheet (BNNS) with ultrasonic stratification using 1‐hexanol, and then hot press the films to make Alkyl‐BNNSs orient in the fluorinated polyimide (f‐PI). The resulting Alkyl‐BNNS/f‐PI composite successfully realizes the synergistic improvement of thermal property and dielectric properties, exhibiting a high heat conductivity coefficient of 2.36 Wm−1 K−1 with a filler content of 4.99 wt.%. Moreover, the permittivity and dielectric loss of the film are as low as 1.76 and 0.0065 at 1 MHz, respectively. This work provides a facile strategy for breaking the bottleneck of making polyimide composites simultaneously with high thermal conduction and low dielectric performance. Highlights: The composite exhibits a high heat‐conducting coefficient of 2.36 Wm−1 K−1.Ultra‐low dielectric constant of 1.76 was achieved by the modification of film.Excellent breakdown resistance and flexibility were endowed with the composites. [ABSTRACT FROM AUTHOR]

The development of polymer‐based dielectric nanocomposites with superior dielectric properties, heat dissipation, and excellent thermal stability remains a significant challenge for advanced electronic and electrical systems. In this work, boron nitride nanosheets (BNNS) and MgAl layered double hydroxide nanosheets (MgAl LDHNS) were utilized as binary fillers and incorporated into polyetherimide (PEI) to fabricate BNNS‐MgAl LDHNS/PEI nanocomposite films by ball milling dispersion and solution casting method. Owing to the exceptional synergistic effect of BNNS with high thermal conductivity and large diameter, combined with MgAl LDHNS with high dielectric constant and small diameter, the dielectric constant and thermal conductivity of the nanocomposite film were enhanced while maintaining low dielectric loss and high breakdown strength. For the BNNS‐MgAl LDHNS/PEI nanocomposite films with filler loading of 12 wt%, the dielectric constant (6.47 at 100 Hz) increased by 73%, the in‐plane thermal conductivity (6.932 W/m·K) and through‐plane thermal conductivity (0.407 W/m·K) increased by 561% and 111%, respectively. And the breakdown strength of the nanocomposite film remains at 82.1 kV/mm. Simultaneously, the thermal stability and mechanical flexibility of the nanocomposite film were maintained. This work presents a promising PEI‐based composite material and offers new insights into the role of two‐dimensional binary fillers with varying sheet diameters in enhancing the properties of polymer‐based composites. Highlights: BNNS‐MgAl LDHNS/PEI nanocomposite film was prepared.The nanocomposite film has high dielectric and thermal properties.The interfacial polarization synergistic enhanced by the 2D binary fillers.A high thermal conductivity path was formed between 2D binary fillers. [ABSTRACT FROM AUTHOR]

Ensuring the stability of composite structures in the marine environment is crucial. The harsh and corrosive nature of marine conditions presents unique challenges, making maintenance a top priority. In this study, the impact of seawater aging on the mechanical, buckling, structural, and thermal properties of glass fiber‐reinforced polymer nanocomposites was investigated. Composites were produced using the VARTM method with 2% nano Al2O3 and 2% nano TiO2. Aging was conducted in a seawater environment at room temperature for 120, 240, and 360 days. Mechanical properties, including tensile, compressive, flexural, impact, and buckling tests, were performed, and water absorption was determined. Structural analysis was carried out using SEM images. The experimental results indicated that the presence of nanoparticles minimized the effect of seawater. TiO2 preserved tensile strength by 10.33%, impact energy by 6.8%, and critical buckling load by 3.06% compared to the pure composite. Al2O3 reduced water absorption to 0.594% and preserved tensile strength by 6.67%, impact energy by 4.02%, and critical buckling load by 2%. Thermal test revealed an increase in thermal conductivity with aging, with the TiO2‐doped composite exhibiting the smallest increase (14.66%). The significance of the obtained results was confirmed through ANOVA analysis. Highlights: Glass fiber‐reinforced nanocomposite was produced with nano Al2O3 and TiO2.The effect of seawater aging was investigated.It showed that TiO2 nanoparticles are a good candidate against seawater aging.The experimental results showed statistical significance. [ABSTRACT FROM AUTHOR]

Fluoroelastomer‐based composites with nano‐sized bismuth oxide (B) and/or graphite (G) as fillers were prepared and characterized using FKM type 1 fluoroelastomer as a matrix. The effects of these fillers used singly or in combination on the crosslinking process, mechanical, thermal, dynamic mechanical, electrical, optical, and high‐energy radiation attenuation properties of FKM were investigated. The results showed that graphite significantly increased the moduli E50 (MPa) of FKM/G and FKM/GB composites by 1026% and 1459%, respectively, compared to FKM. On the other hand, bismuth(III) oxide did not affect the stiffness or elongation at break of FKM significantly. Graphite also imparted electrical conductivity to FKM (10−6 Scm−1), which was reduced by bismuth oxide to 10−12 Scm−1. Furthermore, the linear attenuation coefficients (μ), half‐value layer (HVL), and tenth‐value layer (THV) of pure FKM and FKM composites were evaluated using a 137Cs (662 keV) source, revealing that FKM/B and FKM/GB composites show 47.4% and 35.8% higher μ values, respectively, than FKM. Taking into consideration that the attenuation coefficient of FKM is 10 times higher than conventional elastomers such as natural rubber, these results indicate that thin flexible shielding against high electromagnetic radiation can be achieved to protect different sensitive equipment such as electronic devices used in nuclear power plants, gamma radiation facilities, telescopes, and artificial satellites. Highlights: A fluoroelastomer‐based composite containing 40 phr of bismuth(III) oxide nanopowder presents a gamma attenuation coefficient 47.4% higher than that of the polymer matrix.A fluoroelastomer‐based composite containing bismuth(III) presents a band gap of 2.40 eV.Bismuth(III) oxide nanopowder hinders the electrical conductivity imparted by a conducting filler contained in the fluoroelastomer‐based composite.Fluoroelastomer‐based composites containing graphite or bismuth(III) oxide present enhanced mechanical and thermal properties. [ABSTRACT FROM AUTHOR]

Highlights The high‐performance PPS/PEEK blends/composites were prepared with different mass ratios using polyphenylene sulphide (Solvey, Ryton®‐R‐4‐230 NA) and polyetherether ketone (Victrex, PEEK450 GL 30). All the blend samples had a single Tg, which revealed good compatibility between PPS and PEEK. The Tm was increased from 279.6 to 339.9°C due to addition of PEEK into PPS. Also, addition of PEEK into the blend increased the impact and tensile strength of the PPS material. The impact strength of the blend, PPS/PEEK (20/80) exhibited the maximum value of 113.64 J/m which was higher than that of PPS (70.66 J/m). The tensile strength of the blend was increased continuously with increasing the content of PEEK from 20 to 80 wt. % and reached the maximum value of 160.64 MPa. Additionally, milled carbon fiber (MCF) was also incorporated in order to obtain high strength PPS/PEEK blends/composites with good dielectric property. The dielectric performance of the composites was observed to increase with MCF content (in the frequency range 5.8 to 18 GHz). This investigation relates to high‐performance PPS/PEEK blends and composites. Incorporation of milled carbon fiber resulted promising dielectric properties. Such composites may have Advanced structural EMI shielding electronics and/or aerospace applications. [ABSTRACT FROM AUTHOR]

Polyhydroxyalkanoates (PHAs) have gained interest recently due to their biodegradability and versatility. In particular, the chemical compositions of medium‐chain‐length (mcl)‐PHAs are highly diverse, comprising different monomers containing 6–14 carbon atoms. This review summarizes different feedstocks and fermentation strategies to enhance mcl‐PHA production and briefly discusses the downstream processing. This review also provides comprehensive details on analytical tools for determining the composition and properties of mcl‐PHA. Moreover, this study provides novel information by statistically analyzing the data collected from several reports on mcl‐PHA to determine the optimal fermentation parameters (specific growth rate, PHA productivity, and PHA yield from various structurally related and unrelated substrates), mcl‐PHA composition, molecular weight (MW), and thermal and mechanical properties, in addition to other relevant statistical values. The analysis revealed that the median PHA productivity observed in the fed‐batch feeding strategy was 0.4 g L−1 h−1, which is eight times higher than that obtained from batch feeding (0.05 g L−1 h−1). Furthermore, 3‐hydroxyoctanoate and ‐decanoate were the primary monomers incorporated into mcl‐PHA. The investigation also determined the median glass transition temperature (−43°C) and melting temperature (47°C), which indicated that mcl‐PHA is a flexible amorphous polymer at room temperature with a median MW of 104 kDa. However, information on the monomer composition or heterogeneity and the associated physical and mechanical data of mcl‐PHAs is inadequate. Based on their mechanical values, the mcl‐PHAs can be classified as semi‐crystalline polymers (median crystallinity 23%) with rubber‐like properties and a median elongation at break of 385%. However, due to the limited mechanical data available for mcl‐PHAs with known monomer composition, identifying suitable processing tools and applications to develop mcl‐PHAs further is challenging. [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]

Ceramic thermal barrier coatings (TBCs) with high toughness and low thermal conductivity are important for developing aero engines with high thrust‐to‐weight ratio and thermal efficiency. In this work, the properties of tantalate Y1/6Yb5/6TaO4 (YYT) were optimized by introducing 8 wt.% yttria‐stabilized zirconia (8YSZ), synthesized using spark plasma sintering, as a second‐phase ceramic. The highest toughness (3.57 MPa m1/2) of the YYT/8YSZ composite ceramics was due to multiple toughening mechanisms. The underlying mechanisms of these processes were revealed based on the microstructures and residual stress of the YYT/8YSZ composite ceramics. A shift from an intergranular fracture to a transgranular fracture was caused by the difference between soft‐grain YYT and hard‐grain 8YSZ, which consumed the fracture energy. Furthermore, the formation of microcracks, crack deflection, bridging, and branching were analyzed based on the differences in Young's moduli and thermal expansion coefficients of YYT and 8YSZ. Internal defects and weak connections between the YYT and 8YSZ grains reduced the thermal conductivity of the composites until it reached its lowest value at 1.4 W m−1 K−1. The studied toughening mechanisms could be applied to various composites. Moreover, herein, we provide a new strategy to design and synthesize TBCs with enhanced performance. [ABSTRACT FROM AUTHOR]

This article presents a comprehensive review of the advancements in the use of Date Palm Fiber (DPF) reinforced composites, highlighting their mechanical, thermal, and morphological properties and the enhancements achieved through various modification techniques. Date palm fibers, a sustainable and biodegradable resource, have garnered significant interest due to their potential in reducing environmental impact across several key industries, including building and construction, automotive, and packaging. The review discusses the effects of hybrid approaches and physical and chemical treatments on the mechanical properties of DPF composites, demonstrating improvements in tensile strength, elasticity, and flexural strength through optimized fiber‐matrix bonding and reduced moisture absorption. Thermal behavior analyses through Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), and thermal conductivity underscore the composites’ suitability for applications requiring high thermal stability and conductivity for insulation applications. Morphological studies reveal that surface‐treated fibers integrate more effectively with various polymeric matrices, leading to enhanced composite performance. The practical applications of DPF composites are explored, emphasizing their role in promoting sustainable manufacturing practices. Challenges such as scalability, cost‐efficiency, and performance consistency are addressed, alongside future perspectives that suggest a promising direction for further research and technological development in the field of natural fiber composites. This review aims to solidify the foundation for ongoing advancements and increase the adoption of DPF composites in commercial applications. [ABSTRACT FROM AUTHOR]

Highlights While improving the thermal conductivity of composites, single‐size carbon nanotubes (CNT) often degrade their mechanical properties due to the agglomerates. To overcome this limitation, this study reported thermoplastic resin matrix composites synergistically reinforced with small, medium, and large‐size carbon nanotubes (S‐CNT, M‐CNT, and L‐CNT). Using the thermal conductivity (λ) and mechanical properties (flexural strength [F], compressive strength [C] and tensile strength [T]) as the response values, we conducted 21 sets of mixing design experiments and developed the associated quadratic term models. Further multi‐objective optimization was carried out for the above response values. Optimized multiscale CNT synergistically modified composites (S‐CNT, M‐CNT, and L‐CNT contents of 1.25, 7.02, and 2.56 wt%) exhibited a λ value of 1.168 W/mK, which was 121% higher than that of pure composite and also superior to the same content of S‐CNT‐ (1.031 W/mK), M‐CNT‐ (1.016 W/mK), and L‐CNT‐modified composites (0.983 W/mK). Additionally, the optimized composite demonstrated excellent mechanical properties (F = 1482 MPa, C = 848 MPa, and T = 1759 MPa), which were 13%, 11%, and 13% higher than those of the pure composites, respectively, and also surpassed those of the S‐CNT‐, M‐CNT‐and L‐CNT‐modified composites. Using three different scales of carbon nanotubes modified CF/PPBESK composites. Polynomial modeling of composite's thermal conductivity and mechanical properties. Synergistic interactions between carbon nanotubes to improve the composite's thermal conductivity and mechanical properties. [ABSTRACT FROM AUTHOR]

In chemical reactions of copper(II) acetate dihydrate with imidazolium azide salts in ethanol solution several new homoleptic azidocuprates(II) were obtained. In dependency of the used counter cation various different azidocuprate moieties were crystalized. The doubly charged DMMDIm2+ cation facilitates the formation of mononuclear [Cu(N3)4]2− complex anions, while the utilisation of the (PeMIm)+ ion enables the isolation of a dinuclear [Cu2(N3)6]2− salt. By using the unsymmetrical imidazolium ions (BMIm)+ or (EMIm)+ salts with the trinuclear [Cu3(N3)8]2− complex anion are obtained. With the (DML)+ cation an azidocuprate(II) crystallizes, which contains both [Cu(N3)4]2− and the [Cu2(N3)6]2− anion. The anions in the salt with the (PeMIm)+ cation are interconnected through further Cu−N bonds and form layers with a 2D‐honeycomb structure. The trinuclear units in the (BMIm)+ and the (EMIm)+salts form coordination strands of different structures. [ABSTRACT FROM AUTHOR]

Highlights The relationship between interfacial structure and thermal conductivity in epoxy resin/Al2O3 composite is important but is still elusive. Here, we illuminate this issue by investigating the role of four silane coupling agents in thermal conductivity for epoxy resin/Al2O3 composites. The results show that 3‐glycidoxypropyltrimethoxysilane (KH560) is the best silane coupling agent to modify Al2O3, resulting in the lowest viscosity and the highest thermal conductivity of the epoxy resin/Al2O3‐KH560 composite compared with alternative systems. This is attributed to the strong interfacial interaction between Al2O3‐KH560 and epoxy resin, as confirmed by the Fowkes model and broadband dielectric spectroscopy. The interfacial thermal resistance between the epoxy resin and Al2O3 is also quantitatively measured via a photothermal radiometry technique. The epoxy resin/Al2O3‐KH560 also has the lowest interfacial thermal resistance (1.50 ± 0.02 × 10−6 m2 K W−1), compared with the other three systems. This study advances the understanding of the relationship between interfacial structure and thermal conductivity in polymer composites. The relationship between interfacial structure and thermal conductivity in epoxy resin/Al2O3 composite is understood. The interfacial structure is characterized by broadband dielectric spectroscopy. The interfacial thermal resistance is quantitatively measured via a photothermal radiometry technique. [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]

Polymer composites with lightweight, ultralow dielectric constant, excellent thermal insulation and mechanical properties are in high demand in aerospace, transport, wireless communications and other fields. In this work, the three‐dimensional woven Kevlar/glass hybrid composites (3DKGC) with lightweight, high strength, excellent dielectric and thermal insulation properties were obtained with the Kevlar fiber and glass fiber as the raw materials. The results showed that the volume content of air in 3DKGC is over 82% and the volume density is as low as 0.29 g·cm−3, while the compression strength is as high as 7.68 MPa. 3DKGC exhibits an ultra‐low dielectric constant of 1.21. The wave transmission performance of 3DKGC was simulated using the CST software. The simulation results showed that 3DKGC has a return loss of 0.036 and a gain of 0.9982. Moreover, the 3DKGC provides superior thermal insulation than three‐dimensional woven Kevlar composites (3DKC) and conventional polystyrene foams. In summary, this work offers an attractive material that holds significant potential for application in aerospace, wireless communications and other fields where lightweight multi‐purpose composites are required. Highlights: 3D woven Kevlar/glass hybrid composites (3DKGC) were proposed and fabricated.3DKGC exhibits low density of 0.29 g·cm−3 but high compression stress (7.68 MPa).3DKGC possesses outstanding dielectric and thermal insulation properties.3DKGC leverages the benefits of cost‐effectiveness and holistic functionality. [ABSTRACT FROM AUTHOR]

Two‐dimensional hexagonal boron nitride (hBN) based nanocomposites exhibit excellent mechanical and thermal properties for various electronics, automotive, and aerospace applications. The present work gives a novel approach to fabricating hexagonal boron nitride/epoxy nanocomposites using isopropanol and dimethyl ketone as dispersants in two different routes and to predict mechanical characteristics employing deep learning and machine learning models. Nanocomposites were fabricated by employing casting techniques with varying concentrations of hBN, spanning from 0.25 to 1 wt%, utilizing dispersing solvents. The nanocomposites were analyzed for mechanical behavior, highlighting a notable improvement in the mechanical properties at 0.5 wt% isopropanol dispersed hBN. It showcased 61% improvement in tensile strength, 38.41% increase in flexural strength, and 35.80% increase in flexural modulus respectively as compared to the pristine epoxy. The Halpin Tsai analytical model showed agreement with the elastic modulus calculated experimentally. The fractured SEM micrograph supported the improved dispersion of the hBN nanocomposite. Thermal stability of 0.5 wt% isopropanol dispersed hBN/epoxy nanocomposite revealed an improvement by 8°C at 50% degradation as compared to the pristine epoxy. Linear regression, random forest regression, support vector regression, and deep neural network (DNN) were employed to predict values. DNN proved better results by showcasing low prediction loss and high R2 values (0.99468–0.99966). Highlights: hBN/epoxy nanocomposite with isopropanol and dimethyl ketone as dispersants.0.5% hBN loading in isopropanol exhibited improved mechanical characteristics.The Halpin Tsai model was employed for evaluating theoretical elastic modulus.Improved thermal stability and filler dispersion by optimized hBN/epoxy combination.Deep neural network showed higher R2 value and lower prediction loss. [ABSTRACT FROM AUTHOR]

This research paper focuses on the use of solid biomass waste, specifically a combination of Polyalthia longifolia seed (PLSF) and graphite (GH) powder, as reinforcements in vinyl ester (VE) composites. The composites were produced via the hand layup method, with the filler concentration varying from 0 to 15 wt% of PLSF and 0–9 wt% of graphite. The objective was to examine the influence of the hybrid filler on the mechanical characteristics of the composites. The mechanical properties of composites prepared from P. longifolia seeds and graphite powder were experimentally characterized. These properties included tensile strength, flexural strength, impact resistance, and hardness. The hybrid composite had a maximum tensile strength of 48.4 MPa, and its tensile modulus was 1.66 GPa. The hybrid filler at 15% wt% of PLSF and 6% of graphite has the highest flexural strength, which is around 148 MPa. The ultimate impact strength and hardness were measured to be 41.3 kJ/m2 and 44.5, respectively, after the addition of 15 and 6 wt% of hybrid filler. In comparison to neat vinyl ester resin, the PLSF/GH‐VE composites exhibited an increase in tensile, flexural, impact, and hardness of 2.69, 1.82, 3.03, and 1.59 times, respectively. Hybrid composite surfaces were analyzed using scanning electron microscopes to determine surface characteristics and fractured surfaces. In addition, the PLSF/GH‐VE composites have been utilized in the production of components for four‐wheelers. Highlights: Investigated the impact of hybrid filler‐reinforced vinyl ester composites.Mechanical and thermal properties were experimentally characterized.Surface characteristics and fractured surfaces were examined.PLSF/GH‐VE composites are used in producing components for four‐wheelers. [ABSTRACT FROM AUTHOR]

This study produced and characterized composites based on nitrile rubber reinforced with rockwool fiber (RW) and carbon black (CB). Ten formulations with dual‐filler loading amounts ranging from 0 to 40 phr of CB and RW were designed using a simplex‐centroid mixture. The composites were assessed regarding their rheometric, rheological, mechanical, and thermal properties. The use of the RW in the dual‐filler system contributed to overall improvements in Shore A hardness, tear strength, modulus at 50%, and resilience, as well as reducing the Payne effect. Instead of using 40 phr of CB alone, a dual‐filler system comprising 20 phr of CB and 20 phr of RW lowers the Payne effect by around 60%, improves resilience by 35%, modulus at 50% strain by 8%, and the residual stress at equilibrium (σ∞/σ0) by 7%. On the other hand, the tensile strength is reduced by 23%. The optimum cure time, crosslink density, and maximum decomposition rate temperature were not affected by the rockwool's presence in the dual‐filler system. In general, the use of RW in combination with CB is advantageous mainly because it reduces compressive stress relaxation, which is an important property for sealing applications. Highlights: Dual‐filler systems based on carbon black (CB) and rockwool fiber (RW) offer advantages.RW‐rich dual‐filler systems reduce stress relaxation.RW‐rich dual‐filler systems reduce the Payne effect.CB‐rich dual‐filler systems increase tensile strength. [ABSTRACT FROM AUTHOR]

Thermal and electrical properties were investigated for five nominally phase‐pure high entropy carbide ceramics. The compositions (Hf0.2Nb0.2Ta0.2Ti0.2Zr0.2)C, (Cr0.2Hf0.2Ta0.2Ti0.2Zr0.2)C, (Hf0.2Mo0.2Ta0.2Ti0.2Zr0.2)C, (Hf0.2Ta0.2Ti0.2W0.2Zr0.2)C, and (Hf0.2Mo0.2Ti0.2W0.2Zr0.2)C were synthesized by carbothermal reduction of oxides. The thermal diffusivity and heat capacity were measured from room temperature to 1800°C. The room temperature thermal conductivity ranged from 5.1 W/mK for (Hf0.2Mo0.2Ti0.2W0.2Zr0.2)C to 9.0 W/mK for (Cr0.2Hf0.2Ta0.2Ti0.2Zr0.2)C. The thermal conductivity increased over the temperature range with maximum conductivities of 19.6 W/mK measured for (Hf0.2Mo0.2Ta0.2Ti0.2Zr0.2)C to 29.7 W/mK for (Cr0.2Hf0.2Ta0.2Ti0.2Zr0.2)C at 1800°C. The electron contribution to thermal conductivity calculated from measured electrical resistivity varied from 41% to 52% of the total thermal conductivity. The tungsten and molybdenum containing compositions had higher phonon contributions while the niobium and chromium containing compositions had nearly equal electron and phonon contributions to thermal conductivity. [ABSTRACT FROM AUTHOR]

Maximizing the performance of crystal monochromators is a key aspect in the design of beamline optics for diffraction-limited synchrotron sources. Temperature and deformation of cryo-cooled crystals, illuminated by high-power beams of X-rays, can be estimated with a purely analytical model. The analysis is based on the thermal properties of cryo-cooled silicon crystals and the cooling geometry. Deformation amplitudes can be obtained, quickly and reliably. In this article the concept of threshold power conditions is introduced and defined analytically. The contribution of parameters such as liquid-nitrogen cooling efficiency, thermal contact conductance and interface contact area of the crystal with the cooling base is evaluated. The optimal crystal illumination and the base temperature are inferred, which help minimize the optics deformation. The model has been examined using finite-element analysis studies performed for several beamlines of the Diamond-II upgrade. [ABSTRACT FROM AUTHOR]

This study addresses the fabrication of microporous plasmonic nanocomposites (NCs) by using plasmonic nanoparticles (i.e., gold bipyramids, AuB) as seeds to grow microporous shells, specifically, metal–organic frameworks (MOF) PCN‐224 of increasing thickness from 69 to 138 nm. This method is based on using a previously synthesized Zr6‐oxo cluster and unfolds at room temperature. Notably, it is demonstrated that the concentration of the AuB seeds determines both the yield of NCs and the resultant thickness of the PCN‐224 shell, illustrating the seeded growth mechanism. Furthermore, it is found that the thermoplasmonic response of the NCs is dominated by the thickness of the microporous shell, with thicker shells having enhanced thermal confinement properties than thinner ones. As a proof of concept, the NCs are loaded with cresyl violet (CV), a lysosomal fluorescent marker. This serves to demonstrate the thermoplasmonic‐induced intracellular release of CV by the photostimulation of the AuB's plasmonic near‐infrared (NIR) band. Moreover, the NCs display exceptional efficacy as photodynamic agents when photostimulated at the PCN‐224's Soret band. In summary, this study offers a facile, efficient, and reproducible methodology for the fabrication of NCs with a controlled geometry while unlocking new possibilities in the field of nanoMOFs as multifunctional theranostic probes. [ABSTRACT FROM AUTHOR]

This article presents partially bio‐based unsaturated polyester resins (UPR) based on 2,5‐furandicarboxylic acid (FDCA). Three different FDCA‐based resins are prepared, which are potentially suited as i) general purpose resin (composed of 1,2‐propylene glycol), ii) resin for pultrusion (composed of diethylene glycol and 1,2‐propylene glycol), and iii) resin for pipe liners (composed of neopentyl glycol and 1,2‐propylene glycol). The mechanical and thermal properties of the bio‐based UPR are systematically investigated and compared with analogous fossil‐based UPR composed of phthalic and isophthalic acid, signaling comparable or even better properties for the bio‐based resins depending on the application targeted. [ABSTRACT FROM AUTHOR]

The objective of this study is to seek correlations between phosphate fertilization rates in potato cultivation and the chemical composition and physicochemical properties of the potato starch. Potato starches are prepared from the potato tubers cultivated in two different districts in Hokkaido, Japan, with different soil characteristics using varied phosphate fertilization rates. The chemical composition of the potato starches such as the amylose, phosphorus, and potassium contents and their physicochemical properties such as the swelling power, solubility, and pasting and thermal properties are evaluated. The results show that the phosphate fertilization rate has a moderate and positive correlation with the amylose content, while no correlations are found with any other chemical composition and physicochemical properties, including the phosphorus content. One plausible explanation for the lack of the correlation between the phosphate fertilization rate and the phosphorus content in the starch is that a sufficient amount of phosphorus has already been accumulated in the soils to phosphorylate the starch to the highest possible degree without further application of phosphate fertilizers. The present results imply that reducing the phosphate fertilization rate in potato cultivation in the studied fields has no negative impact on the chemical composition and physicochemical properties of potato starch. [ABSTRACT FROM AUTHOR]

Thin films with pH sensitivity have been a trendsetter in the current research scenario. Edible films for packaging are comparatively newer ones, where the study uses conventional food materials as a source or precursor to fabricate the films. Starch(S) is one such material that is not much exploited in packaging and pH sensing. Here, the study presents the preparation of a new type of sensitive, intelligent film from starch‐chitin(CHN) composites and adds the anthocyanin pigment extracted from the Butterfly Pea flower (BPE). The combination films are much more sensitive to ammonia and formalin and thus suggested for the detection of adulteration in fish. All the films (S, S/BPE, S/CHN, and S/BPE/CHN) are fabricated by the solution casting method. The addition of 10 wt% CHN results in the enhancement of the thermal and mechanical properties of pH indicator films. Owing to the presence of anthocyanin pigment, the films can change their color changes in pH. The developed starch‐based intelligent films display wide color differences from bright red to green over the 1–12 pH range, which is discriminated by the naked eye. [ABSTRACT FROM AUTHOR]

Starch is an essential biopolymer for creating viscous food systems in the food industry. Viscosity behavior is unclear in the literature and varies with the thermal process and moisture content used. This study analyzed how ohmic heating affects the pasting properties of corn starch in response to changes in moisture and temperature. Corn starch is mixed with water at varying ratios (1:1, 1:3, and 1:5). The mixture is heated at 5 °C min−1 using an ohmic heating cooker to 80, 100, and 120 °C. Moisture affects pasting and starch properties. Peak viscosity varies with moisture content, decreasing from 5904 cP (native) to 3204–4510 cP at a 1:1 ratio. At a moisture ratio of 1:3, peak viscosity matched the native sample. Higher peak viscosity (6539 to 8772 cP) occurred at high moisture levels (1:3). Thermal properties confirmed different gelatinization degrees, which is evidenced by a shift in the x‐ray diffraction pattern from A‐type (native starch) to V‐type crystalline. The viscosity and physicochemical properties of corn starch depend on temperature and moisture levels. Moisture has a more significant impact on these properties than temperature. Therefore, varying the moisture content it can improve corn starch properties precisely, making it useful for the food industry. [ABSTRACT FROM AUTHOR]

An additively manufactured reaction‐bonded silicon carbide ceramic composite is fabricated using a bimodal powder feedstock and the binder‐jetting printing technique. On fabricating, the ceramic is investigated to report its composition, mechanical, and thermal properties at room temperature and high temperatures (up to 750∘C$^{\circ }C$). The ceramic has a density of 2.76 g/cc, and shows a hardness of 21.74 GPa, and a flexure strength of 207.5 MPa at room temperature. The mechanical property of flexure strength is used to estimate its failure probability under applied stress, using a Weibull distribution. The mechanical properties and failure probabilities are compared with those of conventionally fabricated reaction‐bonded silicon carbide ceramics reported in the literature. These ceramics were fabricated using methods such as slip‐casting, compacting, and tape‐casting. The comparison is used to elucidate the advantages and areas of improvement of the present additive manufacturing technique for reaction‐bonded ceramics. [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]

Global climate change is predicted to cause range shifts in the mosquito species that transmit pathogens to humans and wildlife. Recent modeling studies have sought to improve our understanding of the relationship between temperature and the transmission potential of mosquito‐borne pathogens. However, the role of the vertebrate host population, including the importance of host behavioral defenses on mosquito feeding success, remains poorly understood despite ample empirical evidence of its significance to pathogen transmission. Here, we derived thermal performance curves for mosquito and parasite traits and integrated them into two models of vector–host contact to investigate how vertebrate host traits and behaviors affect two key thermal properties of mosquito‐borne parasite transmission: the thermal optimum for transmission and the thermal niche of the parasite population. We parameterized these models for five mosquito‐borne parasite transmission systems, leading to two main conclusions. First, vertebrate host availability may induce a shift in the thermal optimum of transmission. When the tolerance of the vertebrate host to biting from mosquitoes is limited, the thermal optimum of transmission may be altered by as much as 5°C, a magnitude of applied significance. Second, thresholds for sustained transmission depend nonlinearly on both vertebrate host availability and temperature. At any temperature, sustained transmission is impossible when vertebrate hosts are extremely abundant because the probability of encountering an infected individual is negligible. But when host biting tolerance is limited, sustained transmission will also not occur at low host population densities. Furthermore, our model indicates that biting tolerance should interact with vertebrate host population density to adjust the parasite population thermal niche. Together, these results suggest that vertebrate host traits and behaviors play essential roles in the thermal properties of mosquito‐borne parasite transmission. Increasing our understanding of this relationship should lead us to improved predictions about shifting global patterns of mosquito‐borne disease. [ABSTRACT FROM AUTHOR]

Herein, this work reports the facile synthesis of a dimer diamine‐based autocatalytic polyol (ACP) and its use in polyurethane foam preparation. The ACP, namely TETRAOL is synthesized in one step, without using solvent, and with 100% atom economy. Additionally, a phosphorous‐modified polyol is synthesized by using 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) and castor oil. In this study, all of the polyol components of the foams are of vegetable oil origin, and amine or tin‐based auxiliary catalysts are not used. The structures of the synthesized autocatalytic polyol as well as other bio‐polyols are characterized by Fourier‐transform infrared (FTIR) and Nuclear magnetic resonance (NMR) spectroscopies. The densities, rise and gel time values, and thermal and mechanical properties of the foams are determined and compared to foams prepared by using a petroleum‐based commercial ACP. The bio‐based TETRAOL‐containing foams display comparable densities and improve thermal properties but longer rise and gel time values concerning the foam prepared by using the commercial ACP. [ABSTRACT FROM AUTHOR]

Highlights This work reports polymer/metal double‐shell microcapsules with polysulfone (PSF) and copper as walls for application in self‐lubricating polymer. First, polyalphaolefin 40 (PAO40) was selected as lubricant oil, and PAO@PSF single shell microcapsules were prepared. A critical issue for the formation of copper layer is the sensitization of PSF shell, which can affect not only the adhesion between PSF shell and copper layer, but also the density of copper layer. The sensitization conditions were discussed in detail, and the corresponding effect on the formation of copper layer was evaluated. PAO@PSF/Cu microcapsules obtained under optimal sensitization condition were characterized by scanning electron microscopy (SEM), thermogravimetric analyzer (TGA), x‐ray energy dispersive spectrometer (EDS) and fourier transform infrared spectroscopy (FTIR). A uniform and compact copper layer improved the thermal properties of microcapsules. PSF/Cu microcapsules maintained relatively complete spherical shape when were heated to 300°C, while the PSF microcapsule softened and deformed at 200°C. The self‐lubricating polyamide 6(PA6) composites containing PAO@PSF/Cu microcapsules were fabricated at 230°C, microcapsules maintained complete structure and uniform distributed in the polymer matrix. Coefficient of friction (COF) and wear rate of PA6 composites were tested under different friction conditions. Compared with pure PA6, 15 wt.% PAO@PSF/Cu microcapsules could reduce the COF by 79.5%, and the wear rate was decreased by 98.3% under 300 rpm sliding speed and 50 N friction load. PSF/Cu double‐shell oil‐loaded microcapsules were designed and prepared. The copper layer effectively improved the thermal properties of microcapsules. The self‐lubricating PA6 composite exhibited excellent tribological properties. [ABSTRACT FROM AUTHOR]

Our society has been pursuing high‐performance biodegradable polymers made from facile methods and readily available monomers. Here, we demonstrate a library of enzyme‐degradable polymers with desirable properties from the first reported step polyaddition of diamines, COS, and diacrylates. The polymers contain in‐chain ester and thiourethane groups, which can serve as lipase‐degradation and hydrogen‐bonding physical crosslinking points, respectively, resulting in possible biodegradability as well as upgraded mechanical and thermal properties. Also, the properties of the polymers are scalable due to the versatile method and the wide variety of monomers. We obtain 46 polymers with tunable performance covering high‐Tm crystalline plastics, thermoplastic elastomers, and amorphous plastics by regulating polymer structure. Additionally, the polymerization method is highly efficient, atom‐economical, quantitatively yield, metal‐ and even catalyst‐free. Overall, the polymers are promising green materials given their degradability, simple and modular synthesis, remarkable and tunable properties, and readily available monomers. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of fiber surface treatment on various properties of hair fiber reinforced composites. Human hair fiber reinforced modified epoxidized soybean oil based composites were prepared by compression molding technique. Acid treatment of hair fibers was carried out by using three different concentrations of HCl solution (0.25%, 0.75%, and 1%, respectively) in order to achieve improvement in adhesion between the fiber and the matrix. Epoxidized soybean oil was modified using methacrylic acid and methacrylic anhydride to form methacrylic anhydride modified epoxidized soybean oil. Rosin acid derivative (a rigid comonomer) was prepared and used as a crosslinker. Fourier‐transform infrared spectroscopy was carried out to study the interaction among the components of the composites. Various properties, namely, mechanical, thermal, flame resistance, and chemical resistance were checked. Scanning electron microscopy of the fractured surface of the composites was carried out to examine the morphologies. Hair fibers treated with 0.75% of HCl showed maximum improvement in all the properties and could be employed as reinforcement in various composites to be used for structural applications. [ABSTRACT FROM AUTHOR]

Our society has been pursuing high‐performance biodegradable polymers made from facile methods and readily available monomers. Here, we demonstrate a library of enzyme‐degradable polymers with desirable properties from the first reported step polyaddition of diamines, COS, and diacrylates. The polymers contain in‐chain ester and thiourethane groups, which can serve as lipase‐degradation and hydrogen‐bonding physical crosslinking points, respectively, resulting in possible biodegradability as well as upgraded mechanical and thermal properties. Also, the properties of the polymers are scalable due to the versatile method and the wide variety of monomers. We obtain 46 polymers with tunable performance covering high‐Tm crystalline plastics, thermoplastic elastomers, and amorphous plastics by regulating polymer structure. Additionally, the polymerization method is highly efficient, atom‐economical, quantitatively yield, metal‐ and even catalyst‐free. Overall, the polymers are promising green materials given their degradability, simple and modular synthesis, remarkable and tunable properties, and readily available monomers. [ABSTRACT FROM AUTHOR]

Polymethyl methacrylate (PMMA) with varied compositions of copper oxide (CuO) nanoparticles was synthesized using in‐situ free radical polymerization. UV–visible, FT‐IR, XRD, FE‐SEM, DSC, and TGA were employed to examine their structure, morphology, and thermal properties. The broadening and intensification of UV absorption, as well as the shift in IR peaks of PMMA with the addition of CuO, confirm their interactions. The reduction in optical bandgap values with the reinforcement of nanofillers confirms the existence of intermediate energy bands in nanocomposites. XRD indicated that polymerization with CuO reduced the amorphous nature of PMMA. The FE‐SEM image revealed that the dispersion of CuO altered the nonporous, rough surface of PMMA into a homogeneous shape. The reinforcement of CuO enhanced the thermal stability and glass transition temperature of PMMA. The mechanical strength, modulus, impact strength, and rigidity of PMMA were significantly improved through in‐situ polymerization. The electrical property analysis revealed that the AC conductivity increased with frequency, temperature, and filler content. The reduction in activation energy of AC conductivity with temperature points toward their semiconducting nature. PMMA/CuO nanocomposites with higher tensile strength, lower bandgap energy, higher conductivity, and thermal properties can be used to make flexible optoelectronic devices. Highlights: A series of PMMA/CuO nanocomposites were synthesized and characterized.Enhanced optical property, thermal stability, and glass transition temperature.Possess excellent dielectric constant and AC conductivity.Mechanical strength and impact resistance of PMMA were greatly enhanced.A promising material for flexible optoelectronic and power storage applications. [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]

Natural fiber composites are not suitable for use in industries due to their flammability and low thermal resistance. Inorganic metal‐based fillers are known to enhance the flammability and thermal resistance of composites, while the thermal and fire‐retardant properties of organic fillers are not commonly known. This study evaluated the mechanical, thermal, and flammability properties of Ceiba petandra fiber (CPF)‐reinforced composites, which were added with snail powder (SP). To study the thermal resistance of the composite, a dynamic mechanical analyzer (DMA) and thermogravimetric analysis (TGA) were applied. SP Filler concentration increased the composite's tensile strength and thermal resistance. DMA test results showed the same trend as the composite's density value. The flame rate parameters of the composite, including the percentage of char yield and the limitation index oxygen (LOI), rose as the SP filler increased. However, the flame rate of the composite dropped because SP filler inhibited the movement of oxygen, combustible gas, and polyester degradation products. The addition of organic fillers in natural fiber composites promises better flammability and thermal resistance. [ABSTRACT FROM AUTHOR]

Novel metastable intermixed composites (MICs) constructed by carbon nanomaterials are expected to achieve high energy content and high combustion efficiency, but traditional preparation technologies always bring barely improvement in performance. Herein, novel PVDF/CuO/Al@CNTs MICs with independent continuous carbon nanotubes (CNTs) conductive networks were prepared by thoroughly utilizing the conductivity and photothermal properties of CNTs. A conductive network can be constructed at the interface of each encapsulated PVDF/CuO/Al particle with the addition of >0.5 wt% CNTs. The great increase in electrical and thermal conductivity of PVDF/CuO/Al@CNTs MICs indicates excellent energy transfer efficiency across the sample. Significant enhancement of the combustion reaction has been achieved, with the minimum ignition energy and ignition delay time of PVDF/CuO/Al@CNTs3 reduced by ~31% and ~50%, respectively. This indicates that the CNTs with unique photothermal properties can be utilized as an effective igniter. Moreover, the optimal PVDF/CuO/Al@CNTs1 MICs enhanced the pressurization rate (~300%), energy output (~55%), and combustion velocity (~200%). The mechanism of the fast combustion reaction can also be discussed by the weak interface interaction and the energy conductive of the CNTs network throughout the sample. This work provides a modern strategy for strong combustion MICs that can be generalized and applied in the field of energetic materials. Highlights: An independent continuous CNTs conductive network was prepared with a small amount of CNTs.The electrical and heat conversion efficiency is greatly improved.CNTs with unique photothermal properties can be utilized as an effective igniter.The laser sensitivity is improved, and the reaction energy, pressure, and pressure rates are significantly increased.The combustion performance was significantly improved, and more intense, and the combustion speed was significantly increased. [ABSTRACT FROM AUTHOR]

Considering the growing interest in lanthanide‐based multifunctional materials two mixed‐ligand complexes [Ln(L)3bipy] (Ln=TbIII, DyIII) with carbacylamidophosphate (CAPh) type ligand – dimethyl‐N‐trichloroacetylamidophosphate (HL) and additional bidentate ligand 2,2'‐bipyridine (bipy) were obtained and studied by X‐ray diffraction study, thermal gravimetric analysis, and luminescence spectroscopy. The obtained complexes are monomeric and isostructural with earlier reported europium analog and crystallizes in the monoclinic system (space group C2/c). They are stable during long‐term storage for at least a couple of years as well as thermally stable up to nearly 200 °C. Both complexes exhibit f–f luminescence upon excitation into the 2,2'‐bipyridine absorption band, being emitters of green (TbIII) and yellow (DyIII) light. The luminescence intensity of the obtained complexes decreases constant exposure to UV radiation for several hours and then stays constant for at least till 32 h. [ABSTRACT FROM AUTHOR]

This article explored the influence of curtain climber fiber and Biochar derived from Kigelia pinnata fruit fiber on a polyepoxide‐based composite material's thermal, mechanical, dielectric, and mechanical properties. Before commencing the composite production process, the surface of the curtain climber fiber underwent treatment with a solution consisting of 5% silane to enhance the bonding between the fiber and the matrix. The hand layup method and compression molding were used to produce the composite panels and tested according to the appropriate standards set by the ASTM. According to these findings, the mechanical properties of the composites were enhanced by adding 30% curtain climber fiber and 5% biochar. The load distribution on the fiber was consistent throughout. The composite's highest strength (EFB3) was 183 MPa, its modulus was 5.9 GPa, and its flexural strength and modulus were 216 MPa and 6.1 GPa, respectively. The impact intensity is 8 J, and the hardness value is 95 on the Shore D scale. In addition, the EFB3 had a maximum interlaminar shear strength of 35 MPa. According to the findings of the SEM surface analysis, the matrix molecules exhibit adhesion to the fiber, which indicates increased bonding. The thermal conductivity and dielectric properties were high for composite with higher biochar particle content. These waste biomass‐converted fruit fiber biochar and curtain climber industrial crop fiber epoxide composite materials may be utilized in a variety of sectors, including aerospace, automotive, household domestic product manufacturing, and defense sectors. Highlights: Extraction and silane treatment of curtain climber fiber.Producing biochar from waste biomass Kigelia pinnata fiber.Fabrication of polyepoxide composite.Siloxane layer improves the strength.Biochar improves the properties of composites. [ABSTRACT FROM AUTHOR]

With the trend of integration and miniaturization of stretchable electronics, thermal management has been a crucial issue. Developing novel materials with high thermal conductivity (TC) and flexibility is urgent. Herein, we report a stretchable polydimethylsiloxane (PDMS)/boron nitride nanosheet (BNNS)@spherical aluminum oxide (Al2O3) composite with high TC and electrical insulation prepared by a two‐step strategy of sucrose‐template and hot‐pressing. An effective foam‐pressing route benefits the composites to form a three‐dimensional thermally conductive networks, improving the in‐plane TC value of the resultant composite to 4.03 W/(mK) at the filler mass fraction of 35.7 wt% and enhancing to 4.66 W/(mK) under 40% stretching ratio. Meanwhile, the composites can be restored to their former state and retain thermally conductive stability with repeated bending and twisting tests. Moreover, the composites were applied in LED with stretching, exhibiting good heat dissipation performance. These results demonstrate this PDMS composite can be potentially utilized as a high‐performance material to solve thermal management problems in flexible electronics. Highlights: The heat conduction network is prepared by sucrose‐template and hot‐pressing.BNNS@P‐Al2O3 fillers are self‐assembled via the electrostatic interaction.The composites exhibit good thermal conduction and superior flexibility.The thermal conductivity of the composite increases after stretching.The composites can retain thermal conductive stability after deformation. [ABSTRACT FROM AUTHOR]

Epoxy resin (EP) is a promising material that exhibits great potential in the fields of packaging and adhesion. However, reducing its brittleness and coefficient of thermal expansion (CTE) at low filler content is still a challenge. To address this problem, three types of MWCNTs nanofluids (MWCNTs NFs) with different shell structures were designed to modify epoxy resin. With the addition of 1 wt% MWCNTs‐M1, the compression, impact, and lap shear strength of the composites increased to 88.97 MPa, 81.39 kJ/m2, 12.69 MPa, respectively, which are 21.7%, 66.1%, and 58.0% higher than pure epoxy. Meanwhile, incorporating MWCNTs NFs also improved the CTE and thermal conductivity, with a 19.7% decrease in CTE and a 40% improvement in thermal conductivity at 2 wt% NFs content. Particularly, the effect of MWCNTs NFs structure on the composite properties was explored, which can be an available reference for designing specific NFs epoxy composites. Highlights: Three types of MWCNTs nanofluids with different structures were designed.The MWCNTs NFs were used in packaging materials for the first time.The impact performance of composite has been improved by 66%.The CTE of composite is 19.7% lower than pure EP.The thermal conductivity of the composite increased by 40%. [ABSTRACT FROM AUTHOR]

The influence of surface modification and some processing parameters on the palygorskite (Pal) dispersion and the mechanical, thermal and rheological properties of the resulting Nylon 6 nanocomposites was investigated. Natural Pal was surface modified with hexadecyl tributyl phosphonium and 3‐aminopropyl trimethoxysilane to produce organoclays with different surface energy values. Nylon 6/Pal nanocomposites were produced by twin screw extrusion and then injection molded, Pal loading was 2 wt. % in all the cases. A screw configuration was designed to impose different level of shear stresses to the nanocomposites during processing, and nanocomposites were extruded at two different screw speeds. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations indicated that Pal was dispersed differently depending mainly on the degree of shear stress and surface modification of Pal. The best tensile mechanical properties were achieved with Pal exhibiting the lowest surface energy value dispersed with the screw having high shear configuration. The fatigue life of nylon 6 improved with addition of Pal. The experimental results give some guidelines for producing Nylon 6/Pal nanocomposites with improved properties. [ABSTRACT FROM AUTHOR]