Improvement In Thermal Stability Research Articles

Al-Doped ZnO/SiO2 Nano-glass Ceramic System: A New Composite System for Improvement in Thermal Stability and Mechanical Properties of Dental Resins

AbstractThis study aims to enhance dental resins' mechanical and thermal properties by reinforcing them with Al-doped ZnO/SiO2 nano-glass ceramic. The synthesis of the nano-glass ceramic involved the addition of Al-doped ZnO nano-powders to a diluted aqueous solution of liquid glass (25 mL) in ethanol (50 mL) at room temperature. The synthesized samples were characterized using TEM, EDS, FE-SEM, and XRD techniques. Various concentrations of the nano-glass ceramic (2, 5, 8, 10, and 15 wt.%) were then integrated with Bis-GMA and TEGDMA. The mechanical properties, including flexural strength (FS), compressive strength (CS), diameter tensile strength (DTS), and flexural modulus (FM), were evaluated. Thermal stability was assessed through TGA analysis, which indicated polymer degradation occurring between 300 and 450 °C. An increase in filler content correlated with enhanced thermal stability. The optimal mechanical properties were observed at a 7.5 wt.% filler content, showing significant improvements in FS (124.652 MPa), FM (9.87GPa), DTS (33.87 MPa), and CS (178.47 MPa).

Multidentate Polymer-Stabilized Buried Interface for Efficient Planar Perovskite Solar Cells.

Buried interface engineering is crucial to improve the performance and stability of perovskite solar cells (PSCs). Although coordination materials have been widely used for buried interface modification, they are generally engineered on one surface of the interface through monodentate or bidentate molecules. Here, we propose that a multidentate polymer, sodium alginate (SA), acts with both surfaces via numerous C═O groups to reinforce buried interfaces. SA effectively reduces buried interface defects, adjusts the energy level alignment, and refines carrier dynamics. Notably, it also induces the growth of a perovskite film that is less tensile stressed and free of voids. Consequently, the champion device efficiency after SA treatment increased from 23.05% to 24.98%, along with significant improvements in both light and thermal stability. This work offers insights into efficiency and stability improvement from the perspective of multidentate polymer anchoring.

Organic Salt Buffer Layer Enables High‐Performance NiOx‐Based Inverted Perovskite Solar Cells

The merits of a low‐cost fabrication process, suitable band structure, excellent wettability to perovskite precursor, and outstanding stability ensure NiOx as a hole transport material with beneficial characteristics to construct high‐performance perovskite solar cells (PSCs). However, direct contact between perovskite and NiOx causes delamination and chemical instability and thus results in poor carrier transport and short device lifespan. Here, we propose a solution for this issue by introducing an organic salt additive 4‐(trifluoromethyl) benzylammonium formate (TFMBAFa) in the perovskite precursor to passivate perovskite film and NiOx@(2‐(3,6‐dimethyl‐9H‐carbazol‐9‐yl) ethyl) phosphonic acid (Me‐2PACz) composited hole transport layer (HTL), and thus construct a buffer layer between perovskite‐HTL interface. The effective diminishing of NiOx/perovskite interfacial reactions and defects results in enhanced carrier transport. Consequently, the target device achieves simultaneous improvements in power conversion efficiency (24.2%), storage stability (T100 > 1400 h), thermal stability (T80 > 1000 h), and operational stability (T70 > 850 h), where T100, T80, and T70 refer to the retention of 100%, 80%, and 70% of initial PCE, respectively. This work provides an effective strategy to advance the performance of NiOx‐based inverted PSCs.

Enhancing piezoelectric coefficient and thermal stability in lead-free piezoceramics: insights at the atomic-scale

Given the highly temperature-sensitive nature of the polymorphic phase boundaries, attaining excellent piezoelectric coefficient with superior temperature stability in lead-free piezoceramics via direct compositional design remains a formidable challenge. We demonstrate the synergistic improvement of piezoelectric coefficient and thermal stability in lead-free piezoceramics via atomic-scale local ferroelectric structure design. Via modulation of the local Landau energy barrier at doping sites, we effectively mitigate fluctuations in piezoelectric d33. Our approach achieves an impressive d33 of ~430 pC/N with a minimal temperature fluctuation range (△d33 ~ 7%) across the room temperature to 100 °C in potassium sodium niobate ceramics. Further optimization through annealing extends this temperature up to 150 °C (△d33 ~ 8%) while maintaining a high d33 of ~380 pC/N, rivaling the performance of classic temperature stable lead zirconate titanate. This work establishes a framework for addressing the dilemma between high piezoelectric coefficient and inadequate temperature stability in lead-free piezoceramics.

Nanomaterials in asphalt cement: exploring their single and combined effects on the physical and rheological properties

Pavement deterioration due to rutting, fatigue, and thermal cracking poses significant challenges to road infrastructure. Traditional asphalt modifiers often fall short in addressing these issues, leading to growing interest in advanced materials such as nanomaterials. This study investigates the individual and combined effects of three nanomaterials: nano-titanium dioxide (NT), nano-alumina (NA), and nano-silica (NS), on the physical and rheological properties of asphalt binders when used in dosages of 0%, 1%, and 2% by the weight of asphalt. This study aims to enhance asphalt performance and contribute to international research efforts focused on pavement durability. The experimental program evaluated the penetration, softening point, mass loss after aging, and viscosity properties, in addition to rutting and fatigue resistance through dynamic shear rheometer (DSR) tests. Scanning electron microscopy (SEM) was also employed to observe morphological changes. Results showed that 2% NA reduced penetration by 3.19%, while 2% NS increased the softening point by 2.41%. The combination of NA and NS had the highest effect on the softening point (F = 6.21, p = 0.008). NA and NT reduced mass loss, with 2% NA lowering it from 0.432% to 0.201%. Viscosity increased by 17.4% with 2% NA, while the NA and NS combination had the most significant overall impact (F = 44.78, p = 0.000). At higher temperatures, 2% NA was the most effective in reducing aging. Optimizing the use of NA and NS, either individually or combined, offers the best improvements in binder stiffness, thermal stability, and aging resistance.

Evaluation of Additives on the Cell Metabolic Activity of New PHB/PLA-Based Formulations by Means of Material Extrusion 3D Printing for Scaffold Applications

In this study, specific additives were incorporated in polyhydroxyalcanoate (PHB) and polylactic acid (PLA) blend to improve its compatibility, and so enhance the cell metabolic activity of scaffolds for tissue engineering. The formulations were manufactured through material extrusion (MEX) additive manufacturing (AM) technology. As additives, petroleum-based poly(ethylene) with glicidyl metacrylate (EGM) and methyl acrylate-co-glycidyl methacrylate (EMAG); poly(styrene-co-maleic anhydride) copolymer (Xibond); and bio-based epoxidized linseed oil (ELO) were used. On one hand, standard geometries manufactured were assessed to evaluate the compatibilizing effect. The additives improved the compatibility of PHB/PLA blend, highlighting the effect of EMAG and ELO in ductile properties. The processability was also enhanced for the decrease in melt temperature as well as the improvement of thermal stability. On the other hand, manufactured scaffolds were evaluated for the purpose of bone regeneration. The mean pore size and porosity exhibited values between 675 and 718 μm and 50 and 53%, respectively. According to the results, the compression stress was higher (11–13 MPa) than the required for trabecular bones (5–10 MPa). The best results in cell metabolic activity were obtained by incorporating ELO and Xibond due to the decrease in water contact angle, showing a stable cell attachment after 7 days of culture as observed in SEM.

Comparative Study of Single and Coaxial Electrospun Antimicrobial Cross-Linked Scaffolds Enriched with Aloe Vera: Characterization, Antimicrobial Activity, Drug Delivery, Cytotoxicity, and Cell Proliferation on Adipose Stem Cells and Human Skin Fibroblast.

The preparation of materials with application in the biomedical field needs to attend some characteristics such as biocompatibility, nontoxicity, adequate mechanical properties, and the ability to mimic the extracellular matrix. Scaffolds for use in cell culture were prepared based on gelatin, polylactic acid (PLA), aloe vera mucilage, and tetracycline. Fibers were prepared in single and coaxial configuration and then cross-linked with glutaraldehyde saturated vapor. The fibers were obtained with cylindric morphology and changed to ribbon morphology and porous membranes, similarly to the extracellular matrix, when cross-linked. Membranes prepared by coaxial electrospinning showed core-shell structures when observed by transversal images, which is beneficial for controlled drug release. Characterization techniques such as scanning electron microscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy demonstrated the cross-linking due to the increase in diameter, formation of imine groups, and improvement of thermal stability. Antibiotic release tests showed that the prevalent release mechanism is diffusion and can be controlled considering the encapsulation effect, when fibers are prepared with a coaxial configuration, increasing the drug release time, making it a suitable material for controlled release. The biological evaluation of the scaffolds was carried out in two cell lines: mammalian adipose stem cells (ASCs), used as a primary cell culture, and Detroit 548 human skin fibroblasts as a dermal cell model. Aloe vera enriched scaffolds showed better activity in contact with both cell lines, exhibiting cell viability values greater than 90% and favorable results in live-dead assays when no damaged cells were observed. Cell proliferation was evaluated using Detroit 548 human skin fibroblast on gelatin-based scaffolds by the staining of the adhered cells; the images showed good confluence and morphology of the cells on the aloe vera and antibiotic loaded membranes for both of the studied configurations. Antibiotic loaded membranes presented antimicrobial activity against S. aureus, and this behavior increased when aloe vera is included. According to the results, the scaffolds prepared on single configuration enriched with aloe vera and tetracycline could be used in dermal tissue engineering as burn dressings, diabetic foot apposite, and skin substitutes, and the scaffolds prepared with a coaxial configuration are recommended for controlled release systems of antibiotics as treatments for chronic wounds such as diabetic foot and burn healing.

Influence of Calcination and Cation Exchange (APTES) of Bentonite-Modified Reinforced Basalt/Epoxy Multiscale Composites’ Mechanical and Wear Performance: A Comparative Study

In this study, bentonite clay was modified through silane treatment and calcination to enhance its compatibility with basalt fiber (BF) and epoxy in multiscale composites. The as-received bentonite (ARB) was subjected to silane treatment using APTES, producing silane-modified bentonite (STB), while calcination yielded calcined bentonite (CB). The modified clays were incorporated into basalt fiber-reinforced epoxy (BFRP) composites, which were fabricated using the vacuum-assisted resin transfer method (VARTM). Analytical techniques, including X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy, confirmed the structural changes in the clays. BET surface area analysis revealed a 314% increase in the surface area of STB and a 176% increase for CB. The modified clays also demonstrated reduced hydrophilicity and swelling behavior. Thermogravimetric analysis (TGA) indicated a minimal improvement in thermal stability, with the degradation onset temperatures increasing by less than 3 °C. However, tensile tests showed significant gains, with CB- and STB-reinforced composites achieving 48% and 21% higher tensile strength than ARB-reinforced composites. Tribological tests revealed substantial reductions in wear, with CB- and STB-reinforced composites showing 90% and 84% decreases in the wear volume, respectively. These findings highlight the potential of modified bentonite clays to improve the mechanical and wear properties of basalt fiber–epoxy composites.

Ultrathin green-emitting LuAG:Ce-Al2O3 composite fine-grained ceramics for high-brightness chip-scale packaging LEDs

To realize green-emitting chip-scale packaging LEDs (CSP-LEDs) with high-brightness, the ultrathin green-emitting phosphor ceramic (PC) with high luminous flux (LF) and luminous efficiency (LE) is urgently explored. LuAG:Ce-Al2O3 fine-grained ceramics (about 150 μm thick) were prepared via vacuum solid-state sintering. Ultrathin LuAG:Ce PC owns LE up to 199.26 lm W−1@50 W as high Ce3+ concentration x = 0.02. Fine-grained composite structure induced by the introduction of Al2O3 results in an increase of LE to 209.95 lm W−1@50 W and an improvement of thermal stability from 91.7 % to 97.2 % at 200℃. It is noteworthy that corresponding optimal packaging CSP-LEDs demonstrates the LF of green lighting up to 978.3 lm@3500 mA. Thus these type of LuAG:Ce-Al2O3 PC is a promising candidate for the color converter of CSP-LEDs.

Thermal Stability Improvement of Cu-Based Catalyst by Hydrophobic Modification in Methanol Synthesis

Water can cause the growth and oxidation of Cu nanoparticles on the surface of Cu-based catalysts, leading to their deactivation. However, during methanol synthesis process from syngas on Cu-based catalysts, water is inevitably produced as a by-product due to the presence of CO2. Therefore, enhancing the stability of Cu-based catalysts during the reaction, particularly in the presence of water, is crucial. In this study, Cu/ZnO/Al2O3 was first subjected to wet etching and then hydrophobically modified using the sol–gel method with methyltrimethoxysilane (MTMS) and the grafting method with 1H,1H,2H,2H-perfluoroalkyltriethoxysilanes (PFOTES) as modifiers. These modifications aimed to mitigate the impact of water on the catalyst and improve its stability. After modification, the catalysts exhibited excellent hydrophobicity and enhanced catalytic activity in the methanol synthesis process. The surface physical properties, composition, and thermal stability of the catalysts before and after hydrophobic modification were characterized by SEM, FT-IR, BET, XRD and TGA. Additionally, molecular dynamics simulations were employed to compare the diffusion behavior of water molecules on the catalyst surfaces before and after hydrophobic modification. The results indicated that the modified catalyst surface formed a micro/nano structure composed of nanosheets and nanosheet clusters, while the hydrophobic modification did not alter the structure of the catalyst. According to the results of simulations, the hydrophobic layers on the modified catalysts were able to expel water quickly from the surfaces and reduce the relative concentration of water molecules at the active sites, thereby improving the stability of the catalyst. Notably, the thermal stability and hydrophobicity of the PFOTES-modified catalyst were superior to those of the MTMS-modified catalyst, resulting in a more significant enhancement in catalyst stability, which aligned with the experimental results.

Thickness dependence and crystallization properties of amorphous GeTe thin films on silicon dioxide

Radio frequency magnetron sputtering was used to prepare the amorphous GeTe thin films on silicon dioxide and the thickness effects on the crystallization behavior were investigated. With the film thickness reducing, the crystallization temperature, crystallization activation energy, amorphous and crystalline resistance increase remarkably, indicating the great improvement in thermal stability and power consumption. Ozawa’s model was used to estimate the crystallization kinetics of GeTe thin films, it shows that nucleation and grain growth occur simultaneously, and grain growth dominates ultimately. XRD analysis demonstrated that the grain size can be reduced and the crystallization process of GeTe thin film can be inhibited with the film thickness decreasing. Furthermore, the thinner film has smaller resistance drift index and surface roughness, which are beneficial to improve the reliability of storage device. T-type phase change memory devices based on 25 nm GeTe thin film were fabricated by 0.13 μm CMOS technology, and the current–voltage and resistance-voltage characteristics demonstrate the excellent electrical performance, including the fast resistance switching between SET and RESET processes, low threshold current and voltage. All the results proved the strong dependency relationships between the crystallization properties and film thickness of GeTe thin film, which paves the way for developing high-density phase change memory in the fields of big data and artificial intelligence.

Bio-based liquid crystal epoxy resins: Toughening and strengthening of conventional epoxy resins with strategically extended spacer layers

Liquid crystal epoxy resin, as an ideal toughening agent, combines the features of liquid crystal ordering and network cross-linking, which can effectively optimize the comprehensive performance of blended epoxy resins and achieve an ideal balance of rigidity and toughness. Here we successfully synthesized rigid and flexible bio-based liquid crystal epoxy resin (THBR-EP) by finely tuning the length of alkyl side chains. Using aromatic diamine as curing agent, a homogeneous network without phase separation was constructed by taking advantage of the different activity but good compatibility with ordinary epoxy resins, which significantly improved the toughness of the blended system. Specifically, only a small amount of THBR-EP(2.5 wt%) was required to exhibit a maximum impact strength of 48.8 kJ/m2. Moreover, the increase in system toughness was accompanied by a benign improvement in flexural strength, modulus and thermal stability. The ordered structure of the liquid crystals and their good compatibility with the resin matrix enhanced the ability to inhibit crack extension and energy dissipation. The feasibility to simultaneously achieve effective toughening and other property improvements of common resins broadens the application of resins under various demanding scenarios.

Synthesis, structural characterization and intense far-red luminescence of Mn4+ -activated SrLaMgTa1-yAlyO6 oxide phosphors

The transition metal Mn4+ activated phosphors have attracted increasing attention due to the potential uses in phosphor-converted lighting emitting diodes (LEDs). Herein, the far-red emitting SrLaMgTa1-yAlyO6:Mn4+ (y = 0−0.15) oxide phosphors were successfully synthesized by the high-temperature solid state reaction, in which the Mn4+ acted as an activator. The monoclinic double perovskite crystal structure, chemical composition, and 4+ state of activator Mn were confirmed by means of X-ray diffraction Rietveld refinement, scanning electron microscopy elemental mapping, and X-ray photoelectron spectroscopy. The optical properties were characterized with photoluminescence excitation and emission spectra, temperature-dependent emission spectra, and electroluminescence spectra. The excitation spectra are interweaved with the ligand-to-metal charge transfer band of Mn−O and intrinsic transitions (4A2g→4T1g, 4A2g→2T2g, and 4A2g→4T2g) of Mn4+, locating at the ultraviolet and blue light region. The emission spectra mainly contain a dominant far-red emission band from 650 to 775 nm with peaks at 695 and 708 nm, which are ascribed to the 2Eg→4A2g transition of Mn4+. Moreover, the cationic substitution strategy with tiny Al3+ occupying Ta5+ octahedral site, promotes the improvement of luminescence intensity and optical thermal stability. The quantum yield of optimal phosphor reaches 88.2 % and the fluorescence intensity at 373 K (100 °C) retains 83.4 % in respect to that at ambient temperature, implying the phosphor with intense and thermally stable luminescence. The phosphor is packaged with 365 nm chip to fabricate an LED device, and the electroluminescence result is quite consistent with the photoluminescence, matching well with the absorption spectrum of the phytochrome. The Mn4+ activated oxide phosphors with intense far-red emission are promising for plant cultivation lighting.

Fabrication and Application of Tannin Double Quaternary Ammonium Salt/Polyvinyl Alcohol as Efficient Sterilization and Preservation Material for Food Packaging.

Food packaging films play a vital role in preserving and protecting food. The focus has gradually shifted to safety and sustainability in the preparation of functional food packaging materials. In this study, a bisquaternary ammonium salt of tannic acid (BQTA) was synthesized, and the bioplastics based on BQTA and polyvinyl alcohol (PVA) were created for packaging applications. The impact of BQTA on antibacterial effect, antioxidant capacity, opacity, ultraviolet (UV) protective activity, mechanical strength, thermal stability, and anti-fog of the resultant bioplastics was examined. In vitro antibacterial experiments confirmed that BQTA possesses excellent antimicrobial properties, and only a trace amount addition of BQTA in PVA composite film could inhibit about 100% of Escherichia coli and Staphylococcus aureus. Compared to BQTA/PVA bioplastics with pure PVA, the experiment findings demonstrate that BQTA/PVA bioplastics show strong antioxidant and UV protection action and the performance of fruit preservation. It also revealed a small improvement in thermal stability and tensile strength. The small water contact angle, even at low BQTA concentrations, gave BQTA/PVA bioplastics good anti-fog performance. Based on the findings, bioplastics of BQTA/PVA have the potential to be used to create packaging, and they can be applied as the second (inner) layer of the primary packaging to protect food freshness and nutrition due to their antioxidant activity and biocompatibility.

Unusual Tm3+ sensitization-induced white-emitting and thermostable improvement in Ba2Y2Ge4O13:Dy3+ phosphor for solid-state lighting and optical thermometry

Currently, the development of single-phase white emitters is an interesting research topic. Researchers have paid much attention to tune white-emitting of Dy3+-activated phosphors via Tm3+ sensitization strategy. However, the role of Tm3+ sensitization on luminescence thermostability was usually underestimated. Herein, color-tunable germanate phosphors Ba2Y2Ge4O13 (BYGO):Tm3+,Dy3+ were prepared. The white light emission is achieved due to the effective energy transfer from Tm3+ to Dy3+. A BYGO:Tm3+,Dy3+-based w-LED exhibits warm white-emitting. Moreover, the back-energy transfer of Dy3+→Tm3+ contributes to the improvement of luminescence thermal stability. Meanwhile, the difference of temperature-dependent Tm3+ and Dy3+ emissions realizes satisfactory temperature sensing properties. This work provides a deep understanding for the role of Tm3+ sensitization strategy on color tuning and thermostable improvement, promoting multifunctional utilizations of Dy3+-activated phosphors.

Production of γ-aminobutyric acid by immobilization of two Yarrowia lipolytica glutamate decarboxylases on electrospun nanofibrous membrane

This study harnesses glutamate decarboxylase (GAD) from Yarrowia lipolytica to improve the biosynthesis of γ-aminobutyric acid (GABA), focusing on boosting the enzyme's catalytic efficiency and stability by immobilizing it on nanofibrous membranes. Through recombinant DNA techniques, two GAD genes, YlGAD1 and YlGAD2, were cloned from Yarrowia lipolytica and then expressed in Escherichia coli. Compared to their soluble forms, the immobilized enzymes exhibited significant improvements in thermal and pH stability and increased resistance to chemical denaturants. The immobilization notably enhanced substrate affinity, as evidenced by reduced Km values and increased kcat values, indicating heightened catalytic efficiency. Additionally, the immobilized YlGAD1 and YlGAD2 enzymes showed substantial reusability, maintaining 50% and 40% of their activity, respectively, after six consecutive cycles. These results underscore the feasibility of employing immobilized YlGAD enzymes for cost-effective and environmentally sustainable GABA production. This investigation not only affirms the utility of YlGADs in GABA synthesis but also underscores the advantages of enzyme immobilization in industrial settings, paving the way for scalable biotechnological processes.

Co-immobilization of magnesium precursor and Candida rugosa lipase on alumina via covalent bonding for biodiesel production

Catalyst development is one of the most challenging aspects in biodiesel production due to the compatibility issue with the feedstocks and catalyst poisoning upon exposure to process conditions. In the present research, chemoenzymatic catalyst was prepared by impregnation of magnesium aluminate (MA) on alumina support, modifying the support using activating agent, and immobilization of Candida rugosa lipase (CRL) onto the support. The optimum immobilization condition was resulting in 85.07 % of activity recovery of immobilized lipase, equivalent to 30.53 % of immobilization efficiency. The catalysts were characterized through XRD, FTIR, FESEM-EDX, NAA and CO2-TPD confirming the mixture of AlO(OH), magnesium aluminate (MA), (MgNO3)2 and Mg2+ on the support. CRL/L-lysine/MA showed remarkable improvement in thermal stability (40 − 70℃), solvents tolerance (ethanol, methanol, isopropanol, tert-butanol), and storage stability at 30 ℃, as compared to free CRL. CRL/L-lysine/MA successfully produced biodiesel yield up to 87.10 % at 200.71 rpm of agitation speed, 13.58 % (w/w) of water content, 10 h reaction time, 15 % (w/w) of catalyst loading, at 50 ℃, using 1:12 of oil to methanol molar ratio, and retaining 46.60 % of biodiesel yield after six cycle. The CRL/L-lysine/MA demonstrated novel catalysts characteristics comprising chemical and biological active species on a single support for biodiesel production from waste cooking oil (WCO).

Towards the understanding of rare earth microalloying on the improvement of thermal stability of intragranular austenite and mechanical property of TRIP steels

Existing sites of dissolved rare earth (RE) atoms have not been accurately identified owning to their extremely low solid-solubility in steels, leaving behind the ambiguity of RE-microalloying on microstructure tailoring and performance optimizing for a few decades. Here, RE clusters are directly observed inside ferrite of TRIP steels, causing solute-drag effect on dislocation movement. RE addition can also enhance the solubility of V in austenite, leading to more precipitations of carbides inside austenite. The austenite-ferrite boundaries assisted by these carbides provide strong pinning effect on dislocation motion from ferrite to austenite, thereby forming the unique core-shell structure of dislocations within intragranular austenite. The dislocation shell offers additional diffusion channels for C/Mn partition and restricts volume expansion of austenite cores, hence increasing the thermal stability of intragranular austenite and optimizing the strength-ductility balance of TRIP steels.

Improving the compatibility of polylactic acid/polycarbonate blends with nanoclay and Joncryl as chain extenders

AbstractThis study aimed to optimize the compatibility and performance of PLA/PC blends by investigating the effects of Cloisite 20A nanoclay (NC) and Joncryl chain extender (CE). PLA/PC blends with varying NC and CE loadings were prepared, and the optimal formulation was identified. The optimal NC and CE content were then used to produce PLA/PC blends with varying PC ratios. The test specimens were produced by mixing the mixture in a twin‐screw micro compounder and subsequent injection molding into dog bone specimens to investigate the thermal, mechanical, and morphological properties of the blends. Scanning electron microscopy and dynamic mechanical analysis confirmed the immiscibility of the unmodified blend, but significant improvements in blend morphology were observed with high NC/CE ratios. The presence of NC/CE resulted in reduced droplet size of dispersed PC phase and a new intermediate glass transition temperature (Tg) in DMA, suggesting partial miscibility. The highest thermal stability improvement was achieved with 5 wt% NC alone or a combination of 5 wt% NC and 1 wt% CE. Composites containing NC/CE showed the most significant improvements in composite properties, demonstrating their effectiveness as compatibilizers and improved compatibility in PLA/PC blends. These results indicate that the use of NC/CE is a promising method for expanding the applicability of PLA/PC blends.

Development of intrinsically flame-retardant bio-thermosets with further enhanced thermal stability through a photo-thermal dual polymerization strategy

In response to safety and environmental concerns, there has been a significant increase in research focused on developing high-performance thermoset materials from sustainable sources. In this study, a sophisticated chemical design approach integrates coumarin and furan moieties into a bio-based UV-dimerizable benzoxazine resin. The newly obtained bio-benzoxazine exhibits a reduced curing temperature along with improvements in both thermal stability and flame-retardant properties compared to conventional thermosetting counterparts. Extensive characterization of the chemical structure of the UV-dimerizable bio-based benzoxazine is conducted through nuclear magnetic resonance, Fourier transform infrared spectroscopy, elemental analysis, and high-resolution mass spectrometry. The photo-dimerization processes are monitored using UV–Vis and NMR techniques. Additionally, the thermally activated curing behavior is scrutinized via differential scanning calorimetry and in situ FT-IR techniques. Remarkably, the fully polymerized bio-thermoset demonstrates exceptional thermal stability, possessing a Td10 of 410 °C and a Tg of 283 °C. Moreover, the resulting thermosets also shows very low flammability, as evidenced by a heat release capacity of 14.6 J·g-1·K-1 and a total heat release of 2.97 kJ·g-1. This study not only outlines a method to enhance the overall performance of bio-polybenzoxazines but also provides a direct and sustainable synthesis route for bio-derived, intrinsically non-flammable thermosetting materials.