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In this study, poly(butylene adipate‐co‐terephthalate) (PBAT) biocomposites were generated from spent coffee grounds (SCGs) or torrefied SCG (TSCGs) using a melt compounding process. TSCGs were obtained at torrefaction temperatures of 230, 245, 260, 275, or 290°C for a duration of 60 min. Torrefaction enhanced the hydrophobicity, grindability, and biomass stability of the resulting composites by eliminating hemicellulose. Various concentrations of SCGs (10 and 20 wt.%) and TSCGs (10, 20, and 30 wt.%) were compounded into PBAT. The thermal, mechanical, and degradation properties of PBAT biocomposites were investigated. As SCGs and TSCGs were introduced, the crystallization temperature drastically increased. Compared with PBAT biocomposites with SCGs, PBAT biocomposites with TSCGs exhibited higher thermal stability and hydrophobicity, and improved mechanical properties. Further, alkaline hydrolysis occurred at a faster rate for biocomposites with biofillers than for neat PBAT. Therefore, this study demonstrated the improved compatibility between SCGs and PBAT by torrefaction. [ABSTRACT FROM AUTHOR]

Highlights Microfibrillated cellulose (MFC) was uniformly dispersed in high‐density polyethylene (HDPE) using a large amount of surfactant, and composites were prepared after removing the surfactant at different contents. The structural, morphological, thermal, and tensile properties of these composites were systematically investigated. The results demonstrated an asymptotic relationship between the amount of surfactant removed and the number of removal cycles. A negative linear correlation was observed between the surfactant content and the tensile strength, tensile modulus, and storage modulus at −20 °C of the composites, while a positive linear correlation was found with the loss modulus at −20 °C. Excessive surfactant adversely affected the dispersion of MFC, as well as the mechanical properties and thermal stability of the composites. However, when the surfactant content was below 2.8%, its impact on the composite properties was minimal, and the tensile strength, modulus, and thermal stability of the composites were significantly improved compared to neat HDPE. These findings indicate that surfactant pretreatment is an effective strategy for dispersing MFC in non‐polar polymers, and controlling the surfactant content in the final product can effectively tailor the properties of the resulting composites. Confirms the relationship between surfactant content and MFC/HDPE composite properties. Surfactant content showed an asymptotic relationship with removal cycles. Surfactant content and mechanical properties exhibited a negative linear correlation. Surfactant content and thermal stability exhibited a negative relationship. Surfactant content had minor impact when below 2.8%. [ABSTRACT FROM AUTHOR]

The segment character of polyurethanes (PUs) determines the micromorphology and properties. The effective segment regulation can customize the favorable performance of PUs. Herein, silicon covalent‐modified polyurethanes (MPUs) were prepared by incorporating diphenylmethane diisocyanate (MDI) and diphenyl silanediol (DPSD) into PU molecules as hard segments via a two‐step method. Distinctive microphase separation structures from sheet morphology to radial sheet or withered flower‐like microdomain were formed by adjusting hydrogen bonding of hard segments and post‐treatment techniques. Thus, with the addition of DPSD in hard segments, the thermo‐optic responses for MPUs occurred due to the different microphase evolution under thermal effect. And with the further addition of DPSD, the effect of thermal stimuli on the transmittance gradually weakened. It was very clear that with increasing the temperature, the transmittance of MPUs showed a gradual increase owing to melting the microcrystals or destroying the ordered accumulation of hard segments. Meanwhile, the high mechanical properties were obtained, higher 15 times tensile strength and more than 100 times elastic modulus than those of pure PU as well as the excellent thermal stability. In sum, this study was of great significance for developing new functionalized PU materials. Highlights: Polyurethanes were prepared by inducing modified silicon functionality.The distinctive microphase separation evolution of MPUs was found.Thermal stimuli responses showed a gradual decrease due to different structure.High mechanical properties and thermal stability were also obtained. [ABSTRACT FROM AUTHOR]

Bismaleimide (BMI) resins is widely used in the aerospace field because of its excellent properties, but its poor toughness limits the possibility of its application in a wider range of fields. Therefore, a novel bio‐compound, 4‐(allyloxy)‐3‐methoxy‐N‐(3‐(triethoxysilyl)propyl)benzamide (AMTPM), was designed and synthesized from renewable vanillin, which has Schiff‐base structure, silico‐oxygen bond structure, and allyl structure. The chemical structure of AMTPM has been characterized and validated by Fourier transform infrared (FTIR) and hydrogen nuclear magnetic resonance (1H NMR). It was found that the addition of AMTPM can effectively promote the curing behavior of BD resins (BMI and diallyl bisphenol A (DBA) was mixed and cured at the ratio of 1:0.87, named BD resins). AMTPM can affect the thermal stability and improve the mechanical properties of BD‐AMTPM resins (BD resins modified by AMTPM in different addition), and the detailed discussion was conducted. With the increase of AMTPM content, the thermal stability of BD‐AMTPM resins was deteriorated while the residual weight percentage at 800°C (Yc) was increased. When the content of AMTPM reached 12 wt%, the results showed that Yc achieved the values at a magnitude of 37.57%. Meanwhile, the glass transition temperature (Tg) achieved 320°C. Among the BD‐AMTPM resins system, the BD‐6 wt% AMTPM has the best toughness and mechanical properties. The impact strength was increased by 29.2%, the tensile strength was increased by 22.1% and the elongation at break was increased by 44%. The fracture morphology of BD‐AMTPM resins was also studied by scanning electron microscopy (SEM) to support the mechanical experimental conclusions. This study provides a more environmentally friendly and convenient modifier, which is of great significance for expanding the application of bismaleimide resin. Highlights: A bio‐based modifying agent (AMTPM) was designed and successfully synthesized.AMTPM has both Si‐O and Schiff‐base structures.AMTPM can effectively improve the toughness of BD‐AMTPM resins through impact and tensile tests. [ABSTRACT FROM AUTHOR]

Highlights To improve the subpar lubricating performance of epoxy resin, this paper presents the preparation of a novel bimetallic phyllosilicate featuring a distinctive rice‐granular morphology, which incorporates nickel and iron metal cations through a facile hydrothermal process. These phyllosilicates were then integrated into the epoxy matrix to form composites. A comprehensive analysis of the target product validates the rationality of the synthesis strategy for the as‐prepared rice‐granular bimetallic nickel/iron phyllosilicate, demonstrating a homogeneous hierarchical structure with numerous tiny nanosheets of nickel/iron phyllosilicate grown in situ on the flat surfaces of the rice‐granular metal–organic frameworks. An adequate addition of nickel/iron phyllosilicates allows for excellent dispersion within the matrix and establishes strongly bonded interfaces, steadily increasing the elastic modulus and hardness. Notably, the average friction coefficients decrease from 0.515 for the pure resin to 0.450 for the composites when the filler content reaches 7%, indicating a significant solid lubrication effect. In contrast, adding just 1% nickel/iron phyllosilicate moderately improves wear resistance, elongation at break, and tensile strength. Furthermore, it was found that as the filler content increased, the weight loss rate was reduced by approximately 43.8%, while the residual char increased by 74.2%, significantly enhancing the thermal stability of epoxy composites at high temperatures. This study offers a promising approach to preparing self‐lubricated epoxy composites with favorable mechanical and thermal properties. NiFePS was successfully synthesized via a facile two‐step self‐polymerization. Excellent mechanical properties of composites could be achieved with low content of NiFePS. The friction coefficient and wear rate were lowered remarkably. The friction mechanism was solid lubrication. [ABSTRACT FROM AUTHOR]

Highlights This study investigated the effect of multi‐walled carbon nanotubes (MWCNTs) and reclaimed gypsum of varying contents on the mechanical properties and thermal stability of polypropylene (PP) composite materials. The results indicated that the incorporation of reclaimed gypsum and MWCNTs powder into PP composites could enhance the tensile strength, impact strength, and bending modulus of PP to a certain extent. The above properties of AGY/MWCNTs/PP composites were increased by 14.6%, 131.8%, and 36.2%, respectively, with the impact properties being significantly affected. Univariate analysis of variance revealed that MWCNTs powder and recycled gypsum exerted a significant impact on the mechanical properties of polypropylene composites. Moreover, the initial weight loss temperature of AGY/MWCNTs/PP demonstrated a notable increase, from 318.71 to 398.48°C, while the maximum weight loss temperature exhibited a comparable rise, from 406.85 to 461.54°C. The impact performance and thermal stability of polypropylene composite materials have been demonstrably augmented. A synergistic effect between reclaimed gypsum and multi‐walled carbon nanotubes in the reinforcement of polypropylene composites was demonstrated. This provides a theoretical framework and practical guidance for the design and preparation of high‐performance and recyclable polymer composites. [ABSTRACT FROM AUTHOR]

Levoglucosenone (LGO), a renewable compound obtained from cellulose biomass, has been utilized to prepare novel monomers bearing alkene functional groups. These monomer derivatives of LGO were subsequently cured via ultraviolet (UV)‐initiated radical thiol‐ene “click” chemistry with commercially available multifunctional thiols to obtain colourless, optically transparent cross‐linked thermosets. The monomers prepared in this work are unique due to utilising the internal double bond of the LGO ring during polymerization as part of the cross‐linked network. The thermal and mechanical properties along with the degradation of thermosets containing both ether and ester linkages within the LGO monomers were studied. These thermosets had tensile strengths of 1.3–3.3 MPa, glass transition temperatures between 23.2 and 27.2 °C, and good thermal stability of up to 300 °C. [ABSTRACT FROM AUTHOR]

Background Results Conclusion Fried dough sticks, widely enjoyed in southeast Asia, are made by frying a mixture of wheat flour and water at high‐temperature. With the move towards industrial production, there is an increasing demand for healthier versions. Understanding the key properties of fried dough sticks and how the ingredients interact is crucial for meeting these health‐focused consumer preferences.In this study, the connections between the dough's rheological and thermal properties, alongside the interactions between gluten proteins and the oil content in fried dough sticks, were examined and analyzed at varying gliadin to glutenin mass ratios (Gli/Glu). The results indicated that a general decrease in the viscoelastic properties of the dough was associated with an increase in the Gli/Glu ratio. Furthermore, a heightened concentration of gliadin was observed to augment the mass loss of gluten proteins, thereby engendering a spatially sparse network structure. Additionally, this excessive presence of gliadin precipitated the thermal instability within the dough, necessitating an augmented chemical force to preserve the stability of the gluten network structure.At the Gli/Glu ratio of 5:5, the gluten protein exhibited enhanced thermal stability and minimal mass loss. At this specific ratio, the gluten network was characterized by a comparatively high prevalence of extended gluten films and short‐chain structures, which resulted in the production of fried dough sticks possessing minimal structural oil content. The study provided a theoretical basis for identifying the Gli/Glu ratio as an effective approach to modulate the oil content in fried dough sticks. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, graphene nanoplatelets were applied to polyester fabrics using the knife‐coating method at different concentrations (50, 100, and 150 g/kg). SEM, DSC, and TGA/DTG analyses were performed. The influence of graphene coating on hydrophobicity and surface roughness was examined by water contact angle (WCA) measurement and root mean square roughness, respectively. Abrasion resistance and tear strength tests were also performed. The effect of graphene used as a filler on the flammability of polyester fabric was evaluated for the first time according to the BS 5852 standard. No significant weight loss (only in the range of 0.4%–1.5%) was observed in the graphene‐coated samples even after 100,000 cycles. While the WCA value was 0 for the uncoated fabric, the blind coating and maximum graphene‐coated sample measured 86° and 95°, respectively. The coating process reduced the roughness of the base fabric, and the decrease continued with the increasing graphene ratio. The tear strength values that were 45.5 N in the warp and 53.6 N in the weft direction in the blind coating, increased to 52.2 and 59.1 N, respectively, at the maximum graphene concentration. Graphene coating enhanced thermal stability, increased hydrophobicity, and improved flame retardancy in the test using a smoldering cigarette. [ABSTRACT FROM AUTHOR]

A lithium‐ion battery separator facilitates lithium‐ion transportation and prevents direct contact between the cathode and anode. Polyimide separators exhibited superior thermal stability and electrolyte wettability. In this study, carboxylated polyimide separators were prepared by electrospinning carboxyl group‐containing monomers. Polyimide separators were prepared with different content of carboxyl group‐containing monomer. Moreover, the thermal property, mechanical property, and electrochemical performance of separators were studied. The carboxylated polyimide separators exhibited lower interfacial resistance and higher ionic conductivity compared with polyimide separators. Moreover, the LiFePO4/Li half‐cell assembled using the carboxylated polyimide exhibited enhanced cycling stability and rate capability. Therefore, carboxylated polyimide separators with superior electrochemical performances are promising candidates for lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Although significant efforts have been undertaken to explore the toughening of epoxy resins, it remains challenges to establish a simple and effective toughening technique which does not compromise its strength, thermal stability and processing performance. In this paper, toluene‐diisocyanate‐trimer (TDI‐T) was utilized to manufacture a novel epoxy‐terminated dendritic modifier TDI‐T glycol diglycidyl ether (TDI‐T GLDE). When the addition of TDI‐T GLDE reaches 20% of the resin mass, the tensile strength, tensile elongation, compressive strength and impact strength were increased by 28.1%, 75%, 24.8%, and 138.0% respectively, compared to E‐51. The thermal properties of the samples have been improved, including an increased glass transition temperature (Tg) from 68.2 to 73.2°C, as well as an increase in the initial decomposition temperature from 240.6 to 257.7°C. The toughening mechanism of TDI‐T GLDE was studied through a combination of mechanical performance tests, thermal performance tests, and resin fracture surface morphology analysis. [ABSTRACT FROM AUTHOR]

Highlights A fluorinated polyimide (PI‐FTD) was synthesized for preparing a thermally conductive PI matrix and composites. Additionally, surface‐treated boron nitride (BN) was incorporated into the PI‐FTD via the solution casting method to form efficient heat paths along the through‐plane direction. The resultant composite demonstrated remarkable characteristics, including an impressive through‐plane thermal conductivity of 3.6 W mK−1, a substantial tensile strength of 69.4 MPa, and excellent thermal stability. When this composite was applied to light‐emitting diodes, it effectively managed heat, reducing the operating temperature by 29°C. The PI‐FTD/BN‐OH composites can potentially improve thermal management in electronic devices. A novel fluorinated polyimide (PI‐FTD) was fabricated. Introducing CF3 functionalities in the PI‐FTD provides high thermal stability. BN‐OH reinforced the thermal and mechanical properties of the composites. The PI‐FTD/BN‐OH composites achieved excellent thermal management. [ABSTRACT FROM AUTHOR]

Phosphors with multifunctional applications have attracted extensive research, especially in thermometer and anti‐counterfeiting fields. Herein, a series of Pr3+‐doped YNbO4 (YNO) phosphors with adjustable photoluminescence and red persistent luminescence (PersL) performances are developed. YNO host exhibits the blue self‐activated luminescence, and the different Pr3+ emission peaks possess various thermal stability properties due to the thermal quenching channel generated by the intervalence charge transfer state between Pr3+ and Nb5+ ions. Two kinds of fluorescence intensity ratio models with high absolute and relative sensitivities are realized to measure the temperature under dual‐wavelength excitation. Moreover, YNO:Pr3+ exhibits the red PersL with a duration of about 120 s upon ceasing the UV excitation light source. The fabricated YNO:Pr3+‐polydimethylsiloxane films display different luminescence patterns with the passage of time after turning off UV light, which can cleverly achieve dynamic conversion. These results demonstrate that YNO:Pr3+ phosphor has potential applications in dual‐wavelength excited thermometry and dynamic anti‐counterfeiting fields. [ABSTRACT FROM AUTHOR]

Highlights High temperature shape memory polymers (HT‐SMPs) have great utilization in self‐deployable hinges/morphing structures for space/aerospace, and high‐temperature sensors/actuators for electronics. However, HT‐SMPs have many drawbacks, such as low stiffness, strength, thermal stability, and dynamic mechanical properties. This work aims at improving these properties of highly utilized space grade HT‐SMP, PEKK (polyether ketone ketone), by reinforcing it with low‐cost carbon fibers (CFs), and developing its composite via additive manufacturing. The additively manufactured CF/PEKK composites are annealed at 200 °C (CF/PEKK‐A200) and 250 °C (CF/PEKK‐A250), and for the first time, investigated for shape memory effect (SME). The shape fixity and the shape recovery of the CF/PEKK‐UNA (un‐annealed), CF/PEKK‐A200, and CF/PEKK‐A250 are noted to be 95.97%, 88.95%, and 86.40%, and 88.70%, 92.70%, and 95.19%, respectively with a significant weight saving potential of ⁓21%. Dispersion of CFs in PEKK and suitability of processing parameters (blending, extrusion, and 3D printing) are confirmed through scanning electron microscopy (SEM). Thermal degradation temperature (Td$$ {T}_d $$) of the printed CF/PEKK composite (⁓568 °C) is found to be ⁓3.5% higher than PEKK (⁓549 °C). CF/PEKK‐A250 exhibited the highest storage modulus (4438.23 MPa), ~158% higher than PEKK (1722.3 MPa), while CF/PEKK‐A200 demonstrated the highest tensile modulus (10.9 GPa), which is 138.5% higher than PEKK (4.57 GPa) and 312.88% higher than CF/PEKK‐UNA (2.64 GPa). Moreover, CF/PEKK‐A200 exhibited 237.46%, 138.51%, 127.08%, 61.48%, 32.93%, and 50.35% higher tensile modulus than PEEK, PEKK, PEK, CF/PEK, CF/PEEK, and CF/PEKK composites, respectively, showing great potential to replace them. Printed CF/PEKK composites are investigated for shape memory behavior. The printed composites exhibited outstanding shape memory properties. Printed‐A200 exhibited 138.51% enhanced tensile modulus than pure PEKK. Also, the printed‐A200 showed 313% enhanced modulus than printed‐UNA. Td$$ {T}_d $$ (568 °C) of the printed composites is found ⁓4% greater than pure PEKK. [ABSTRACT FROM AUTHOR]

Highlights The homogeneous dispersion of multi‐walled carbon nanotubes (MWCNTs) in a polymer matrix significantly affects the overall properties of composites. In this study, MWCNTs/epoxy (EP) composites were prepared using DeoxyriboNucleic acid (DNA) as a dispersant. The MWCNTs were uniformly dispersed in a phenalkamine curing agent and crosslinked with an epoxy resin matrix. The non‐covalent functionalization of DNA‐dispersed MWCNTs was confirmed by characterizing both the pristine and DNA‐modified MWCNTs. Additionally, the dispersion state and stability of MWCNTs in the curing agent solution were evaluated. Tensile strength and single‐lap‐shear (SLS) were employed to assess the mechanical properties of the composites. The results indicated that the DNA‐dispersed MWCNTs composites exhibited superior strength and toughness, with tensile and shear strengths of 46.81 and 19.64 MPa, respectively, at optimal ratios. These values represent increases of 68.38% and 50.96% compared to pure EP. Dynamic mechanical thermal analysis (DMTA) revealed that the energy storage modulus of DNA‐dispersed MWCNTs/EP composites increased to 2722 MPa, a 24.7% enhancement over pure EP. Furthermore, the thermal properties of the composites were thoroughly investigated. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) showed that the initial decomposition temperature of the DNA‐assisted dispersed composites rose to 330°C. The macromolecular relaxation of the EP materials occurred at higher temperatures, leading to an increased glass transition temperature. DNA was used to disperse MWCNTs in phenalkamine curing agent. MWCNTs/EP composites were made by crosslinking DNA‐dispersed MWCNTs with epoxy resin. DNA‐dispersed MWCNTs boosted tensile and lap shear strength. Thermal properties improved due to DNA‐dispersed MWCNTs, and increased the energy storage modulus of the composite. [ABSTRACT FROM AUTHOR]

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

Over the past years, poly(lactic acid) or polylactide (PLA) is commonly researched as a possible replacement for traditional fossil‐based polymers because of its compostability, biocompatibility, and high mechanical properties. PLA has a variety of applications in packaging, biomedical, and structural. However, PLA has limitations, such as high brittleness, low thermal stability, and a slow crystallization rate, which limits the wide range of applications. To overcome these limitations, the literature reports that blending PLA with other polymers, such as poly(ε‐caprolactone) (PCL), is an economically viable approach. Although blending PLA with PCL is considered a feasible approach, the blend system still suffers from immiscibility, depending on the blend composition. This review aims to highlight recent developments from 2014 to date on the processing of PLA/PCL blends, including their composites, with a primary focus on morphological characteristics and mechanical and thermal properties, including their potential applications in various sectors. [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethanes (TPUs) are a family of thermoplastic elastomers with great properties such as high elongation and excellent chemical and abrasion resistance, which are processable by conventional melting methods. Nevertheless, TPUs lose mechanical properties and thermal stability at higher temperatures. In this work, we designed and synthesized a new TPU with limited crosslinking of the soft segments in order to improve its performance at high temperatures while preserving processability. Additionally, the new TPU maintains its transparency. With the incorporation of 10% trifunctional polyol, the Tg was increased by 7°C, the storage modulus at room temperature (25°C) was improved by 412 MPa (136%), the rubbery plateau was extended by 32°C and the thermal stability was enhanced by 4°C at T5. Moreover, the TPU with controlled crosslinking of the soft segments shows exceptional creep behavior both at room temperature and at 150°C, where the creep rate decreased by 80%. The new TPU shows limited decrease in tensile properties and can be processed by conventional thermoplastic processing techniques. Highlights: Design and synthesis of a new TPU with limited crosslinking of the soft segments.Incorporation of the crosslinks into the soft segments preserves system processability.Enhanced mechanical and thermal properties while preserving system transparency.High temperature application window extended by 32°C.Creep rate at 150°C lowered by 80%. [ABSTRACT FROM AUTHOR]

Bamboo fiber has garnered considerable attention owing to its high specific strength and renewability. However, the hydrophilic nature of the material must be carefully managed to create a bamboo composite with usable thermal‐mechanical properties. Herein, the NaOH‐treated bamboo fiber (particle size ≤200 μm) was used to produce bamboo charcoal (BC). Then, recycled low‐density polyethylene containing BC composites was fabricated by varying the BC composition (between 2 and 8 wt%). Effects of different BC wt% in the BC/recycled low‐density polyethylene composites (denoted as xBCPE, where x indicates BC wt% in the composites) were analyzed for tensile strength, morphology, and thermal properties. In addition, the water absorption capacities of the BCPE composites were compared. These xBCPE composites showed excellent thermal stability and low water absorption properties. Therefore, they are potential candidate materials for electrical device packaging with partial degradability. Highlights: Bamboo charcoal (BC) was prepared via low‐temperature pyrolysis of alkaline‐treated bamboo fiber.BC displayed strong interfacial interaction with recycled low‐density polyethylene.Proportion of BC on the composite properties was investigated and furnished.The xBCPE composites demonstrate low water absorption and excellent thermal stability.The reinforced composite (4BCPE) shows great promise as a functional material. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries are widely used in various industrial and consumer applications. One key point is the thermal stability of these batteries regarding safety. Thermogravimetric analysis and differential scanning calorimetry (DSC) are ideal methods to study the thermal properties of differently charged electrode materials without safety issues associated with thermal runaway tests of the complete cell. This study shows a significant relationship between state of charge (SOC) and power released by the electrode material during the heating process. For the utilized cathode material LixCoO2, a linear relationship is apparent between the decomposition temperature and the decomposition energy, enabling estimation of the SOC. The decomposition temperature of differently charged anode material strongly correlates with the selected heating rate. This study reveals substantial dependencies of the measured power on the utilized crucibles, providing a systematic approach to benchmark the impact of crucible type on observed DSC signals during battery component analysis. [ABSTRACT FROM AUTHOR]

Highlights Increasing the thermal stability and thermal conductivity of polydimethylsiloxane (PDMS) is a crucial issue for thermal applications. This paper focuses on enhancing PDMS's thermal and structural properties by incorporating nanocomposite into the PDMS matrix. An investigation of the impact of rGO‐CaCO3 nanocomposite on the thermal and structural properties of PDMS was performed using Field Emission Scanning Electron Microscopy (FESEM), X‐ray diffraction (XRD), the thermogravimetric analysis and differential thermal analysis (TGA‐DTA), and thermal analyzer tests. It was observed that PDMS doped with rGO‐CaCO3 nanocomposite shows better thermal stability, thermal conductivity, and higher crystallinity. The thermal stability was enhanced significantly by adding a 5% rGO‐CaCO3 nanocomposite, and the initial and end degradation temperatures rose to 492°C and 605°C, respectively. The thermal conductivity of pure PDMS is approximately 0.17 W/mK, whereas a conductive elastomer filled with 5% rGO‐CaCO3 nanocomposite exhibits a thermal conductivity of 0.44 W/mK at a temperature of 20°C. In contrast, the thermal diffusivity is enhanced from 0.13 mm2/s to 0.366 mm2/s. Additionally, the Fourier Transform Infra‐Red (FTIR) spectrum at 1411 cm−1 becomes sharp and noisy, and an additional peak arises at 1398 cm−1, corresponding to the vibrational rocking of the CC bond and COC bond in CaCO3 and rGO. The manuscript focuses on the development of conductive elastomer by incorporating rGO‐CaCO3 doped and its effect on the morphology, structure, and thermal properties of PDMS. The variation in peak intensity observed in XRD attributed to disparities in the crystalline structure of PDMS due to the inclusion of nanocomposite. The thermal degradation range is observed to shift toward the upper end. The degradation temperature at the beginning and end of the process is observed to move to 492°C and 605°C, respectively, upon introducing a 5% rGO‐CaCO3 nanocomposite. The addition of 5% rGO‐CaCO3 filled conductive elastomers shows a significant improvement of approximately 2.6 times in heat conductivity than bare PDMS. [ABSTRACT FROM AUTHOR]

To further increasing the toughness performance of thermoset resins without sacrificing their other properties is still a challenge task. In this study, the soft core–soft shell nanoparticles based on polydopamine‐modified cellulose nanocrystals (P‐CNC) were synthesized and seamlessly integrated with Bisphenol A‐aniline benzoxazine (BA‐a). Notably, the results underscore the remarkable impact of a mere 0.2 wt% of P‐CNC on BA‐a, boosting the impact strength of the modified system to 19.5 kJ/m2. This achievement represents a substantial 140.7% increase compared with pure polybenzoxazine. Moreover, the flexural strength reaches 133.4 MPa, surpassing pure polybenzoxazine by 16.2%. And the modified system exhibits a 10% weight loss temperature (Td10) at 321.7°C, accompanied by a char yield of 27.6%. This holistic approach results in a notable enhancement of the toughness performance while concurrently maintaining the flexural strength and the thermal stability of the modified system. Consequently, the integration of soft core–soft shell nanoparticles emerges as a promising strategy for enhancing thermoset resin properties without undermining their existing exceptional attributes. Highlights: The core–shell nanoparticles were made by dopamine and cellulose nanocrystals.The core–shell nanoparticles can enhance the toughness of polybenzoxazine.Nanoparticle‐matrix interactions and deformation led to improved properties. [ABSTRACT FROM AUTHOR]

A series of halloysite nanotube‐silica (HNTs‐SiO2) nanocomposite fillers were prepared by in‐situ assembly, and a reinforced SiO2/SR composite was obtained by filling them into silicone rubber (SR). The morphology and structural characterization of HNTs‐SiO2 and HNTs‐SiO2/SR and the properties of the HNTs‐SiO2/SR were studied. As a result, the small particle size SiO2 was firmly anchored onto the HNTs surface, and the obtained HNTs‐SiO2 nanofillers were uniformly dispersed in SR. At a 30 phr fixed filler loading, the weakest filler network and the best filler dispersion were obtained when HNTs content in HNTs‐SiO2 was 5%. This resulted in a maximum tensile strength obtained of 6.2 MPa, 1.55 times that of SiO2/SR with the same filler loading, and a maximum elongation at break of 418%, 1.67 times that of the SiO2/SR with the same filler loading, and at the same time the tearing strength and hardness are also improved. Furthermore, the silicone rubber also showed improved thermal stability, with an initial degradation temperature increase of 30°C under a nitrogen atmosphere. Highlights: HNTs–SiO2 nanocomposites were successfully prepared by the self‐assembly method and used as fillers in SR as a new type of reinforcing material.The 1D HNTs act as a barrier to prevent SiO2 aggregation and improved fillers dispersion.The elongation at break and tensile strength of 5% HNTs‐SiO2/SR are 67% and 55% higher than those of SiO2/SR, respectively.The silicone rubber also showed improved thermal stability. [ABSTRACT FROM AUTHOR]

Highlights The over‐loading of heat‐resistant fillers in silicone rubber creates a contradiction between heat resistance and mechanical properties, thus greatly limiting the durability of silicone rubber products in cutting‐edge applications and complex scenarios. To address this issue, silicone rubber was filled with octavinyl polyhedral oligomeric silsesquioxane (POSS) and carbon nanotubes (CNT) and crosslinked with 2,5‐dimethyl‐2,5‐di(tert‐butylperoxy)hexane (DBPMH) in an attempt to obtain composites with excellent mechanical properties and great thermal stability. Optical microscopy and X‐ray diffraction analyses revealed the size of POSS crystals decreased and the characteristic peaks disappeared after the peroxide crosslinked the polymer at elevated temperature. Specifically, silicone rubber composite filled with 0.1 phr POSS and 1.0 phr CNT exhibited a tensile strength of 10.2 MPa and elongation at a break of 450%. Further, the strength and elongation could be kept after thermo‐oxidative aging at 250°C for 32 h. Thermogravimetric analysis results demonstrate that the addition of POSS and CNT into silicone rubber exhibits a synergistic effect, markedly improving the thermal stability of the material. This method provides a valuable reference for manufacturing silicone rubber products that possess both excellent mechanical properties and high thermal stability under extreme working conditions. A novel silicone rubber composite with excellent mechanical properties and thermal stability was prepared. A small amount of octavinyl polyhedral oligomeric silsesquioxane (POSS) and carbon nanotubes exhibited a synergistic effect to improve thermal stability. The dependence of the morphological evolution of POSS crystals in SR on the 2,5‐dimethyl‐2,5‐di(tert‐butylperoxy)hexane and temperature was studied. [ABSTRACT FROM AUTHOR]

Cellulose acetate (CA) has found broad applications for many years. However, the development of mechanically strengthened CA materials without losing the processibility in solution remains quite difficult. In this work, novel CA thermosets are reported that can be readily constructed by employing alkyl diboronic acid as a crosslinking agent, which has allowed convenient reconfiguration of CA networks without demanding catalysts or harsh processing conditions. Various properties including thermal stability, creeping resistance, rheological and mechanical strength have been successfully improved by using small amounts (1–5 wt%) of diboronic acid. The dynamic cross‐linked network based on boron chemistry has facilitated solution processing during three times of recycling. Control experiments have shown that alkyl diboronic acid can deliver superior mechanical strength to CA as compared to aryl diboronic acid or single‐arm alkyl boronic acid. Based on the importance of CA materials, this work should be attractive to the design of reprocessible CA thermosets with high performance. [ABSTRACT FROM AUTHOR]

In recent years, the packaging industry has utilized electronic packaging materials with epoxy resin (EP) and high‐performance fillers, exhibiting superior mechanical properties and thermal conductivity. Spherical silica micro‐powder (SSP) is a critical thermal conductive filler but faces challenges due to its inorganic nature. Surface modification is essential to improve SSP's compatibility and dispersion in organic matrices for effective use in EP‐based composites. In this paper, the effects of the following four modification methods on SSP/EP composites were studied: (1) the processes include co‐modification with dimethyldimethoxysilane (DMDMS) and trimethylethoxysilane (MTES), (2) modification with NaOH, (3) co‐modification with DMDMS and MTES in an alkaline environment after NaOH modification, and (4) co‐modification with methyltrimethoxysilane (MTMS) and propyltrimethoxysilane (PTMOS). Through comprehensive characterization and evaluation, it is evident that modification schemes 1, 3, and 4 significantly enhance SSP's hydrophobicity, dispersibility, and compatibility with EP. This led to the improvement of thermal conductivity and stability of the composite, and modification scheme 4 showed the highest enhancement, with a 42.6% increase in thermal conductivity. Moreover, the mechanical properties of modified composite materials, such as bending strength, impact resistance, and tensile strength, surpass those of unmodified SSP/EP composite materials. The study provides valuable insights for reducing manufacturing costs and enhancing productivity in the electronic packaging sector. [ABSTRACT FROM AUTHOR]

In this study, we succesfully synthesized bio‐benzoxazine resins using eugenol, a bio‐based phenolic compound, in combination with three distinct functional amines: ethanamine, aniline, and hexane‐1,6‐diamine. Characterization of the resulting bio‐benzoxazine resins, namely E‐ea (eugenol, ethanamine), E‐a (eugenol, aniline), and E‐dh (eugenol, hexane‐1,6‐diamine), was performed through 1H NMR spectroscopy, FTIR spectroscopy, high‐resolution mass spectrometry, and elemental analysis. Thermal properties were investigated using thermogravimetric analysis (TGA) for both the eugenol‐derived bio‐benzoxazines (E‐ea, E‐a, E‐dh) and their corresponding polybenzoxazines (PE‐ea, PE‐a, PE‐dh). Notably, all eugenol‐based polybenzoxazines exhibited excellent thermal stability with very similar characteristics. Our findings suggest that the presence of allyl groups in eugenol promoted a more cross‐linked network structure compared to other functional groups on amines. As a result, eugenol‐derived bio‐benzoxazines demonstrated superior thermal properties, illustrated by their impressive char yields: PE‐ea; 45.6%, PE‐a; 45.1%, and PE‐dh; 44.1%. [ABSTRACT FROM AUTHOR]

The customization of polymeric prototypes is available to meet the specific needs of individual patients, considering tissue location and patient‐specific characteristics. Poly (butylene adipate‐co‐terephthalate) (PBAT) has shown great promise among various polymers in this scenario due to its biodegradability and processability properties. However, the effect of geometry changes on the mechanical properties of PBAT 3D scaffolds and their mechanical stability after in vitro degradation are crucial to determining the final application. This study focuses on the structural, morphological, and mechanical characterization of PBAT prototypes with different architectures and evaluating their mechanical properties before and after in vitro degradation. Three‐dimensional structures were 3D printed with rectilinear deposition angles of 15°, 30°, 45°, 60°, 75°, and 90°. Mechanical tests revealed that the prototype architecture influenced the stiffness, elongation, and maximum tension, where a greater resistance was observed for filaments containing the lowest angles. The thermal stability of PBAT remained unaffected either by reprocessing or hydrolytic degradation; however, in vitro degradation affected the mechanical behavior by increasing the stiffness and decreasing the elongation of the scaffold. Biological assays have demonstrated the nontoxic nature of PBAT and its potential to promote cell viability at a rate of 95%. These findings underscore the possibility of optimizing the PBAT design and structure to tune the mechanical properties and contribute to advancing tissue engineering strategies. [ABSTRACT FROM AUTHOR]

In this study, the thermal characterisation of natural rock samples from Zimbabwe for low‐temperature industrial thermal energy storage (TES) applications was carried out. Thermal stability, specific heat capacity, thermal diffusivity, thermal conductivity and density were determined. Variations in these parameters were evaluated and their impact on thermal storage performance was analysed. Basalt and dolerite samples from different locations were found to have average specific heat capacities of 826 and 853 J/kg K, respectively, at room temperature. Insignificant variations were observed with differences of 3.4% for basalt and 1.7% for dolerite samples. Also, negligible differences of 0.3% and 0.7% in densities for rocks of the same type but of different origins were obtained for basalt and dolerite samples, respectively. However, significant variations in thermal diffusivity of all the igneous and metamorphic samples were observed with quartzite rock exhibiting the highest value of 2.1 × 10−6 m2/s, while the values for the other samples range from 0.9 × 10−6 to 1.6 × 10−6 m2/s. This implies that the thermal efficiency of sensible TES systems that use different or the same rock types from different locations can be significantly high to be overlooked. Thermo‐gravimetric analysis results revealed that the rock samples studied have good thermal stability for low‐temperature heat storage applications. [ABSTRACT FROM AUTHOR]

In this work, surface‐modified Ce‐Zr oxides and ZnO nanoparticles were conveniently prepared by dopamine (Dpa) treatment and then composited with epoxy (EP) by hot pressing. Thermogravimetric analysis (TGA) and UV‐shielding properties of the EP composites with surface modification with Dpa‐CZ and Dpa‐ZnO were measured. The TGA results showed that the modified treated fillers had no loss of heat resistance of the matrix and had an enhancement effect on the initial and maximum decomposition temperatures. In addition, the UV‐shielding properties of EP composites after Dpa‐CZ and Dpa‐ZnO modifications both showed a significant enhancement effect compared to pure EP. The T(UVA) of the 0.5 wt% Dpa‐ZnO modified composite decreased to less than 0.017%, and the T(UVB) decreased to less than 0.0059%. The T(UVA) of the 0.5 wt% Dpa‐CZ modified composite decreased to less than 15.98%, and the T(UVB) decreased to below 1.14%. The composites have both excellent thermal stability and UV‐shielding efficiency. [ABSTRACT FROM AUTHOR]

Pulverized coal (coal) possesses a layered structure similar to graphite and is a potential reinforcing filler. In this paper, ball milling is used to reduce the particle diameter of coal. The coal is modified with KH‐560 to obtain K‐COAL and prepared K‐COAL/styrene‐butadiene rubber (SBR) composites. In addition, carbon black (CB) is modified to obtain CB‐Si69, K‐COAL and CB‐Si69 are added to SBR in different ratios to prepare COAL/CB/SBR composites. The results show that the addition of K‐COAL can improve the vulcanization performance, thermal stability, and mechanical properties of SBR composites, but the reinforcing effect is weak. In the COAL/CB/SBR composites, the vulcanization and mechanical properties of the composites gradually increase with the increase of CB, while those of the thermal stability decrease. The tensile strength of the 10 phr COAL/30 phr CB/SBR composite is 24.1 MPa, which is elevated by 1105% and 205% compared with the pure SBR and 40 phr K‐COAL/SBR composites, respectively. The composites maintain high elasticity while the tensile strengths are greatly improved, and the mechanical properties are significantly enhanced. In conclusion, this paper provides a reference for the clean utilization of coal and shows new possibilities for finding new fillers to replace CB. [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]

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]

Poly(butylene adipate‐co‐terephthalate) (PBAT) is one of the solutions to the energy crisis and white pollution. However, the poor thermo‐oxidative stability limits its wide applications. In this work, Chrysanthemum morifolium extract (CME) as a natural additive was used to modify the PBAT. The oxidation onset temperature (OOT) results showed that the CME could provide PBAT with high thermal oxidation stability. By the presence of 2.5 wt% CME, the OOT value of PBAT‐CME2.5 increased by 52°C compared with the neat PBAT. The outstanding antioxidant capacity is attributed to the excellent free radical quenching capacity of CME, whose main components consist of six kinds of phenolic compounds. Moreover, the PBAT‐CME1.5 composite could achieve the balance between the mechanical property and thermo‐oxidative stability, the OOT result of PBAT‐CME1.5 increased by 42°C, the tensile strength reached 103.1%, and the elongation at break could retain 91.4% of that of neat PBAT. Besides, the processing property, degradation performance, and surface hydrophobic nature of modified PBAT samples were all improved. This work proposes a facile method to obtain completely natural biodegradable composites to expand the practical applications of PBAT. Highlights: The main components in CME are phenolic compounds.CME showed high free radical scavenging efficiency.CME improved the thermal oxidation stability of the PBAT matrix.The addition of CME could still maintain good mechanical properties of PBAT.The introduction of CME promoted the degradation of PBAT films. [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]

Lignin is an abundant and sustainable resource that exhibits numerous attractive functional properties as a reinforcing agent for benzoxazine‐based composites, due to its stiffness, thermal stability, and high carbon content. However, the low quality of lignin particles dispersions associated with the weak particles‐matrix interactions reduces the reinforcement capability. In this work, hybrid lignin/silica (NaLS/SiO2) nanoparticles were obtained from sodium lignosulfonate (NaLS) and tetraethylorthosilicate (TEOS) under basic conditions. The particles were characterized by transmission electron microscopy (TEM) confirming their spherical morphology and narrow nanometric‐size distributions. The hybrid particles were incorporated into conventional benzoxazine (BA‐a) and a difuran biobased benzoxazine (SA‐dfda) to prepare nanocomposites with different mass compositions (3, 5, and 10 wt%). Morphological, mechanical, dynamo‐mechanical, and thermal properties of the obtained composites were assessed. All the materials exhibited a homogenous filler dispersion that contributed to improve the reinforcement properties. Hybrid nanoparticles proved to be an interesting alternative as a filler in the benzoxazine matrix to prepare high‐performance thermosetting composites. [ABSTRACT FROM AUTHOR]

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

It is challenging to endow poly(methyl methacrylate) (PMMA) with good dielectric properties and UV absorption capacity while simultaneously overcoming its poor heat resistance. Herein, we report for the first time a novel organic–inorganic hybrid (PMMA‐HBPSi) derived from methyl methacrylate (MMA) and hyperbranched polysiloxane (HBPSi) fabricated via γ‐radiation curing. The typical properties (thermal stability, optical characteristics, and dielectric properties) of the hybrids were systematically investigated and discussed. The results demonstrated that the incorporation of HBPSi into the PMMA resin not only increased the thermal resistance, dimensional stability, and dielectric properties but also remarkably reduced the UV transmittance. Specifically, in comparison with pure PMMA, the initial degradation temperature (Tdi) of PMMA‐HBPSi increased by 31°C, with no phase transition occurred in a temperature range of 60–230°C, thus illustrating a significant improvement in the glass‐transition temperature. Moreover, the thermal expansion coefficient decreased by 86.9% at temperatures exceeding 118°C. The UV transmittance of PMMA was also found to decrease by 80% at 295 nm after the introduction of HBPSi. These attractive features of PMMA‐HBPSi demonstrate that the new approach proposed here is suitable for developing high‐performance organic glasses for optical, aviation, and electronic applications. [ABSTRACT FROM AUTHOR]

In this work, a number of urethane‐modified polyesteramide (UmPEA) films were developed from mahua and castor oils, which are renewable resources. Mahua oil and diethanolamine were reacted to form mahua fattyamide, which was then reacted with itaconic acid to prepare polyesteramide. In order to make the UmPEA films, different proportions of polyesteramide and castor oil as polyols were reacted with isophoronediisocyanate. The UmPEA films showed excellent chemical resistance against water, acid, alkali, salt, and organic solvents and were found insoluble in common organic solvents. The thermal stability of the UmPEA films was investigated through TGA and DSC analyses, and their Tg values are between 69.1°C and 56.1°C for UmPEA films, which indicated that a higher content of CO enhances the Tg, and it was also found that the films were highly stable up to 230°C. The Ea values [224 kJ mol−1 (Tp1) and 226 kJ mol−1 (Tp2)] indicate that the castor oil enhances the thermal stability of the films due to better cross‐linking density occurring through the high hydroxyl groups of CO as the polyol which also showed better flame retardancy in the synthesized UmPEA films. Our findings demonstrate that the newly developed UmPEA films can be potent coating materials. [ABSTRACT FROM AUTHOR]

A series of ester‐ and fluoro‐containing thermoplastic polyimide (PI) films, PEsI‐1 ~ PEsI‐4 have been prepared by the two‐step thermal imidization procedure via the soluble poly(amic acid) (PEsAA) precursors from the copolymerization of four monomers, including the dianhydrides of bisphenol A dibenzoate‐3,3′,4,4′‐tetracarboxylic acid dianhydride (TMBPA) and 3,3′, 4,4′‐biphenyl tetracarboxylic acid dianhydride (BPDA) and the diamine monomers of 4‐aminophenyl‐4′‐ aminobenzoate (APAB) and 2,2′‐bis(trifluoromethyl)‐4,4′‐diamino biphenyl (TFMB) in the polar aprotic solvent of N‐methyl‐2‐pyrrolidinone (NMP). The PI films obtained from the high‐temperature dehydration of the PEsAA solutions exhibited the good thermal stabilities with the glass transition temperatures (Tg) over 269°C, the 5% weight loss temperatures (T5%) higher than 480°C, and the linear coefficients of thermal expansion (CTE) values in the range of 17.7 × 10−6/K–33.6 × 10−6/K in the temperature range of 50–250°C. Meanwhile, the PI films showed good thermoplasticity in the dynamic mechanical analysis (DMA) tests, in which the storage modulus of the PI films dropped sharply in the temperature range of glass transition of the polymers. At last, the PI films exhibited the good dielectric properties with the breakdown voltages (Vb) over 5200 V, the dielectric strength (Ds) higher than 210 V/μm, the dielectric constants (Dk) in the range of 3.26 ~ 3.32 at the frequency of 10 GHz, and the dielectric dissipation factors (Df) of 0.0038 ~ 0.0047. Compared with the commonly used PEsI‐ref film for high‐frequency flexible copper clad laminates (FCCL), the currently developed PI films exhibited the obviously increased Tg values, decreased CTE values, and comparable dielectric properties. [ABSTRACT FROM AUTHOR]

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

Benzoxazine resin shows great potential as matrix for high performance composites, possessing good processabilty, dielectric property, mechanical property, and thermal properties, but its further application is limited by low crosslinking density and poor curing activity, especially for mono‐cyclic benzoxazines. In this work, melamine, a tertiary amine with a stable triazine structure, was introduced into the aldehyde‐containing mono‐cyclic benzoxazine, in order to achieve higher crosslinking density, higher curing activity, and better thermal properties. The chemical structure of prepolymers was verified by Fourier transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance (1H NMR) spectra, the curing behavior was investigated by differential scanning calorimetry, the thermal properties of polymers were studied by thermogravimetric analysis (TGA) and thermal mechanical analysis (TMA). It was found that the introduction of trifunctional melamine (MA) could lower curing temperature and promote the curing degree. Additionally, a proper amount of MA could increase the crosslinking density and thermal properties of the resultant polybenzoxazine. For example, poly(BZ‐3MA) showed the highest thermal stability with the temperature at 5% weight loss (Td5) of 415°C, carbon residue (Yc) of 67.7%, 23°C, and 2.9% higher than those of poly(BZ). Moreover, the glass transition temperature of poly(BZ‐5MA) reached 204.06°C, 36.51°C higher than that of poly(BZ). [ABSTRACT FROM AUTHOR]

The development of lightweight composites with desirable thermo‐mechanical properties is progressively increasing. Phthalonitrile (PN) based composites have shown great potential in this regard. However, the basic thermal properties of PN composites required for engineering design are not yet fully understood. In this work, we investigated the thermal stability, thermal expansion behavior and thermal conductivity of PN composites reinforced with carbon fiber (CF) and high silicon fiberglass (HSF) via combined experimental studies and numerical simulations. The results indicated that CF/PN performs better in thermostability than HSF/PN at temperatures below 500°C. Moreover, the incorporation of CF and HSF lowered the coefficient of thermal expansion (CTE) and thermal insulation of PN. At room temperature, the in‐plane CTE of CF/PN and HSF/PN were 1.97E‐6 and 9.24E‐6°C−1, respectively, while the out‐plane thermal conductivities of CF/PN and HSF/PN were 0.65 and 0.34 W/(m K). It is worth noting that an excessively high fiber volume fraction would lead to poor thermal insulation and lightweight properties of the PN composites, while a low fiber volume fraction would result in poor stiffness and thermal dimensional stability. Determined via TOPSIS model, a fiber volume fraction range of 50%–60% was ideal for both composites with comprehensive optimal properties, respectively. [ABSTRACT FROM AUTHOR]

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

Uneven separator porous construction inevitably raises lithium‐ion migration barriers within the separator and thus limits overall lithium‐ion battery (LIB) performance. In this research, serial LIB separators with various porous constructions were prepared precisely by adjusting the synchronous bidirectional drawing temperatures to confirm the bidirectional drawing mode‐determined porous constructions and subsequent mechanical properties, thermal stability and electrochemical properties of separators. Crystal structure analyses, porous construction diagnoses, mechanical property characterizations and electrochemical tests reveal the competitive relationship between lamella slip and separation during the synchronous bidirectional drawing process. Lamella slip weakens at lower drawing temperatures, enhancing lamella separation and molecular chain rupture within amorphous regions. Therefore, a separator with broken fibrils presents optimized permeability and smoothed ion migration channels, but inferior mechanical properties and thermal stability. Excessive temperature highlights lamella slip, which damages the pore‐forming process, worsens separator permeability and increases ion migration resistance. An appropriate drawing temperature of 100 °C maximally balances lamella slip and separation behaviors, retains intact fibrils and homogenized porous construction, which endows the separator with strengthened mechanical properties, isotropic thermal stability and optimized electrochemical performances. This study provides new insights for synchronous bidirectional drawing in practical separator fabrication and clarifies separator structure‐determined LIB performances. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

In this work, this study aimed to overcome the inherent disadvantage of low thermal stability and brittleness of epoxy resins. A novel modifiers containing alkynyl‐ and allyla‐ groups, (E)‐1‐(4‐(allyloxy)‐3‐methoxyphenyl)‐N‐(3‐ethynylphenyl)methanimine (MNEM) was prepared and confirmed by Fourier transform infrared spectroscopy (FTIR) and 1H‐nuclear magnetic resonance (1H NMR), and selected to improve the thermal stability and toughness of bisphenol A‐type epoxy resin (E51). The blend resins were produced by blending with different contents of MNEM into E51 resin, named E‐MNEM resins. Meanwhile, the thermal stability, mechanical properties, and micromorphology of E‐MNEM blends were analyzed in details. It was found that the thermal stability of E‐MNEM resins was improved by increasing the proportion of MNEM. Compared with E‐0MNEM resin, when the MNEM concentration reached 40 wt%, the char yield (Yc) increased from 14.95 to 29.62%, reflecting a 98.1% improvement. In addition, an appropriate concentration of MNEM could be conductive to improving the mechanical properties. An improvement of 25.5 and 7.1% in elongation and tensile strength along with the maximum value of 17.6 kJ/m2 for the impact strength was achieved by the cured E‐MNEM resins containing 20 wt% of MNEM. Finally, the fracture surface morphology of the E‐MNEM resins was analyzed by the scanning electron microscope (SEM). [ABSTRACT FROM AUTHOR]

L‐ and D‐ form oligo(lactic acid)s (OLLA and ODLA) grafted α‐cellulose (OLLA‐g‐cellulose and ODLA‐g‐cellulose) were prepared by the graft polycondensation reaction in C6H5CH3 medium at 130°C and 380 mm of mercury pressure. Para‐toluene sulphonic acid (5 wt% of oligo(lactic acid)) was used as a catalyst whereas potassium persulfate (0.01 wt% of oligo(lactic acid)) was used as a co‐catalyst in the graft polycondensation reaction. OLLA and ODLA with a degree of polymerization (DP) 6–7 used in polycondensation reaction were also prepared by ring‐opening polymerization of L‐ and D‐lactides at 140°C for 10 h with stannous octoate (C16H30O4Sn) as a motivator, L, and D monomer of lactic acids as co‐motivators. FTIR analysis proved the bonding of OLLA and ODLA onto the α‐cellulose surface. The thermal properties of poly(L‐lactic) acid (PLLA) composites were explored by thermal analysis (TG, DTA, and DTG). Degradation, melting, and maximum weight loss temperature of the composites were increased with the increase of grafted cellulose up to 10% and then decreased. TG and DTA results showed that the incorporation of grafted α‐cellulose (grafted cellulose) can improve the thermal properties of PLLA composites. Highlights: Synthesis of oligo(lactic acid)s from L‐ and D‐lactides by ring‐opening polymerization reactions.α‐cellulose extraction and graft modification with oligo(lactic acid)s.Preparation of grafted α‐cellulose composite with PLLA matrix.Evaluation of thermal properties of the grafted α‐cellulose‐reinforced composites. [ABSTRACT FROM AUTHOR]

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

In this study, the combined effect of algae loading and in‐house produced coupling agent on thermal and mechanical properties of polylactic acid (PLA) prepared by melt compounding were investigated. The PLA‐grafted with maleic anhydride (MA) (PLA‐g‐MA) was used as a coupling agent to improve the interfacial adhesion between PLA and algae. The extent of grafting level was confirmed with FTIR and direct titration method. The results demonstrated the dependence of thermal stability and tensile properties on the grafting level of MA, and also on the concentrations of algae. Thus, it could be deduced that combination of algae at low concentrations (5 and 10 wt%) and PLA‐g‐MA with high grafting level can significantly improve the thermal stability of PLA. High grafting level of MA, showed increase in thermal stability of PLA. On the other hand, at high grafting level, there was an improvement in tensile modulus of PLA. The morphological analysis indicated better adhesion between algae and PLA, in composites containing PLA‐g‐MA with high grafting level. Overall, PLA/algae composites with improved interfacial adhesion and thermal stability were successfully prepared, in the presence of PLA‐g‐MA with high grafting level. [ABSTRACT FROM AUTHOR]

This study reports how hybrid nano‐filler can enhance the tensile strength, electrical properties and thermal stabilization of PAN (polyacrylonitrile) nanocomposite films. The nano‐fillers used are graphene oxide (GO), single‐wall carbon nanotubes (SWCNT), and a hybrid of both. The combination of both nano‐fillers was made by dispersing GO in DMAc (dimethyl acetamide) and then adding SWCNT to the solution. The solution was mixed well using ultrasonication and high‐speed stirring. 1 wt% amount of nano‐filler solutions was added to PAN liquid to make PAN nanocomposite films. The films were tested for mechanical properties, electrical resistivity, thermoxidative stabilization, and thermal stability. The results showed that adding nano‐fillers to PAN significantly improved its tensile strength. GO increased the tensile strength by 42.9% (38.3 MPa), while SWCNT increased it by 57.3% (42.15 MPa). The combination of both (0.5 wt% SWCNT + 0.5 wt% GO) had a remarkable effect, increasing the tensile strength by 96% (52.53 MPa). This was because the combination of both prevented SWCNT from agglomerating together and made it interact better with the PAN, forming a complete network. The combination of both also made the PAN oxidize and stabilize early and efficiently during heating, which made its residual weight increase by ~5.5% more than pristine PAN in TGA. The electrical resistivity and SEM micrograph data correlate with the thermal analysis data, showing that PCG (1 wt% combination) reached the percolation threshold because of the benefits of both GO and SWCNT. The combination of both also showed 95.6% synergy in tensile strength compared to individual nano‐fillers, indicating its potential for efficient reinforcement. Highlights: Hybrid filler boosts PAN strength from 26.8 to 52.53 MPa, surpassing PC, PG.TGA: ~5.5 wt% increased residual weight in 1 wt% hybrid‐reinforced PCG composites.Hybrid undergoes GO decomposition, early oxidation and improved stabilization.PCG composite: Enhanced oxidation, improved stabilization via SWCNT network.PC & PCG composites show low volumetric resistivity due to SWCNT network. [ABSTRACT FROM AUTHOR]