Differential Scanning Calorimetry Methods Research Articles

Use of a hydrosilylation reaction for the preparation of structure-controlled boroxine-based polyborosiloxanes

The structure of organosilicon vinyl-containing boroxine was confirmed by 1H nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. Its thermal properties were studied using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) methods. The ability of boroxine to undergo hydrosilylation using the Karstedt's catalyst was investigated on various organosilicon substrates. Boroxine was shown to be involved in these reactions as a cross-linking agent. The formation of dynamic boroxine cross-links allowed the analysis of the reaction products by NMR spectroscopy, including the use of polyfunctional hydride-containing reagents. In all cases the addition proceeds selectively to the β-position and with complete conversion. The structure of the resulting polyborosiloxane containing 1.4 mol% of modified units was also confirmed by 1H NMR spectroscopy, and its thermal and rheological properties were studied.

Ca(Mo,W)O4 Solid Solutions Formation in CaMoO4‐CaWO4 System

AbstractThe formation of solid solutions in the CaMoO4‐CaWO4 binary system is investigated by X‐ray diffraction, Raman spectroscopy, and scanning electron microscopy methods. The intermixtures of CaMoO4 and CaWO4 components are sintered in 600—1200 °C temperature range (in 100 °C increments). The solidus of the CaMoxW(1‐x)O4 system is studied by the differential scanning calorimetry method in the x = 0.3 … 1.0 range. CaMoO4‐CaWO4 phase diagram is constructed up to 1550 °C. The minimal sintering temperature in order to get CaMoxW(1‐x)O4 solid solution is shown to be 800 °C. Cathodoluminescence study of CaMoxW(1‐x)O4 compounds showed higher intensity of molybdate luminescence type.

Development of Technologies for Processing Polypropylene Foil Waste and Their Use in the Production of Finished Products

This work aims to assess the possibility of using packaging industry waste to modify polypropylene products (PPs). The products were made in the form of extruded foil and injected samples. The products were produced using regranulate made of polypropylene cast foil. Maleic anhydride-modified polypropylene (MAPP) and polyolefin elastomer (POE) with a glycidyl ester functional group were used to modify the polypropylene. The samples were produced based on 50% foil waste reground and 50% pure PP. The rheological properties of the blends were assessed using the melt mass flow rate (MFR) technique; thermal properties using the differential scanning calorimetry method (DSC). The products manufactured using the injection molding method were subjected to an analysis of mechanical properties, such as tensile strength and impact strength. Also, in the case of film samples, tensile strength was assessed. Color-change assessments with CIE L*a*b* were carried out for all materials. Injection-molded products based on recycled metallized cast foil showed favorable mechanical properties such as tensile strength (1 MAPP = 26.7 MPa; 2 MAPP = 27.1 MPa), which was higher than the original material (cPP = 20.7 MPa). Also, for the films produced from regrind, the tensile strength was at a level similar (1 MAPP = 24.6 MPa; 2 MAPP/POE = 25.1 MPa) to the films extruded from virgin materials (cPP = 24.9 MPa). The introduction of a POE additive to the blends resulted in increased impact strength (1 MAPP/POE = 31 kJ/mol; 2MAPP/POE = 18 kJ/mol; 3 MAPP/POE = 11 kJ/mol) in relation to unmodified samples (cPP = 7 kJ/mol). The introduction of a POE additive to the tested mixtures improved the impact strength of the injected products by almost 4 times for sample 1 MAPP/POE and 2.5 times for sample 2 MAPP/POE in comparison to virgin cPP. These studies confirmed that foil waste can be successfully used to modify polypropylene products shaped both in the injection and extrusion processes.

Crystals of para-quaterphenyl and its trimethylsilyl derivative. I. Growth from solutions, structure and crystal chemical analysis by the Hirschfeld surface method

The results of crystal growth of para-quaterphenyl (4P) and its derivative – 4,4''-bis(trimethylsilyl)-para-quaterphenyl (TMS-4P-TMS) from solutions are presented. It has been established that TMS-4P-TMS crystals exhibit better growth characteristics compared to 4P. Parameters of phase transitions of 4P and TMS-4P-TMS in closed crucibles were refined using the method of differential scanning calorimetry. The crystal structure of TMS-4P-TMS in the triclinic space group P1 (Z = 2) has been decrypted for the first time using single-crystal X-ray diffraction and studied over a wide temperature range. Crystallographic analysis of the studied compounds in crystals was performed using the Hirshfeld surface method, and modeling of intermolecular interactions was conducted.

Synthesis, vibrational, thermal, topological, electronic, electrochemical stability and DFT studies of new DABCO based ionic liquids

The design of new ILs with different anions could provide interesting physico-chemical properties and for these reasons, the knowledge about the synthesis, the thermal, vibrational, topological, electronic, electrochemical properties and interaction between the selected cation-anion in these ILs are important subjects. Therefore, the understanding about these properties of these compounds is an important subject of study. In this work, we studied three ionic liquids based on the 1-decyl-1,4-diazabicyclo[2.2.2]octane, DABCO-cation, where the corresponding anions were [Br]-, [PF6]-, and [N(SO₂CF₃)₂]-. The syntheses of these bicyclic DABCO ionic liquids are based on an alkylation reaction of 1,4-diazabicyclo[2.2.2] octane and 1-bromodecanefollowed by anion exchange. The obtained ILs are characterized by 1H, 13C, 19F and 31P-NMR spectroscopy. Vibrational spectroscopy studies are conducted by infrared (FTIR/ATR) and Raman spectroscopy in the wavenumber range 600–4000 cm-1 and 45–3500 cm-1, respectively. Furthermore, the thermal stabilities were investigated using the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) methods. Results indicate that the thermal stability follow the order [C10DABCO][Br]<[C10DABCO][PF6]<[C10DABCO][N(SO₂CF₃)₂]. Additionally, the structural parameters, electrostatic potential (ESP) maps, interaction energies, non-covalent interaction (NCI), atoms in molecule (AIM) analysis, natural bond orbital (NBO), frontier molecular orbital (FMO) analysis and Electrochemical window (ECW) are studied and analyzed by means of DFT calculations at the M06–2X-GD3/AUG–cc–pVDZ level of theory.

Анализ компонентного состава масла какао методом дифференциальной сканирующей калориметрии

Consumer properties of chocolate depend largely on the quality of cocoa butter, which affects the technological processes of chocolate production. This article introduces a new method of calorimetry-based mathematical modeling applied to polymorphic forms of cocoa butter. The authors studied various samples of cocoa butter from different manufacturers using the method of differential scanning calorimetry. The results of experimental studies were processed as a Gaussian distribution. The new method of cocoa butter quality assessment relied on experimental data processed as distribution dependencies of polymorphic cocoa butter forms. The latter were identified as follows: 1) a low-melting form (10–18 °C); 2) polymorphic form α (17–24 °C); 3) metastable form β' (27–29 °C); 4) polymorphic form β (28–30 °C). The authors also calculated the proportion of polymorphic forms of cocoa butter according to their melting point. The method facilitated the quality assessment of cocoa butter, which renders good prospects for the chocolate industry.

Synthesis and characterization of self-healable supramolecular hydrogel based on carboxymethyl cellulose for biomedical applications

Hydrogels have been widely used in biomedical fields including tissue engineering, drug delivery and cell delivery and 3D cell delivery due to abundant water content in their hydrophilic three-dimensional networks and having soft tissue similar to the human body. In recent years, supramolecular hydrogels (SHG) formed by the inclusion complex between polyethylene glycol (PEG) and macrocycles such as cyclodextrin (CD) have attracted much interest due to their excellent biocompatibility and great potential in biomedical. In this research, a carboxymethyl cellulose (CMC)-based graft copolymer was prepared by using acrylic acid (AA) and maleic anhydride functionalized β-CD (β-CD-MA) as comonomers and ammonium persulfate (APS) as initiator. Then, a self-healable supramolecular hydrogel was synthesized by formation of a host-guest inclusion complex between CMC-g-poly (AA-co-β-CD-MA) as host molecule and cytosine- and guanine-modified PEG as guest molecules. The prepared hydrogel was characterized by Scanning Electron Microscope (SEM), X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance spectroscopy (1H NMR). The thermal stability of hydrogel was also determined by thermal gravimetric (TGA) and differential scanning calorimetry (DSC) methods. In addition, the loading and release profiles of metformin hydrochloride (MH) drug as a model on hydrogel was investigated. The results indicated that the drug release from the hydrogel peaks around 360 min and aligns with the Ritger-Peppas model. The hydrogel's self-healing property was examined at ambient temperature and 37 °C. It showed 70 % healing in 1.5 h and completed recovery after 9 h.

Enhancement of the thermal, electrical properties and mechanical properties of graphene doped novel copolymers bearing coumarin side groups

In this study, a new monomer 3-acetyl coumarin-7-ylacrylate (Ac-Kum) was synthesized. A series of copolymer were prepared by using (Ac-Kum) and methyl methacrylate (MMA) in different ratios. The structure characterization of the compounds was carried out by FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. Graphene doped polymer composites were prepared at different rates (1%, 2% and 5%). The thermal behavior of the polymer composites were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) methods. Thermal stability of 1%, 2% and 5% graphene composites of homopolymer was determined as 324 °C, 345 °C and 350 °C, respectively. The dielectric properties of the polymer composites were investigated as a function of frequency. Dielectric constant, dielectric loss and ac conductivity values of homopolymer were determined as 6.13, 0.11, 1.02×10−09 S/cm and 5% graphene composite were determined 49.30, 7259, 9.26×10−07, respectively. Microhardness tests were carried out under a load of 100 g and in 10 seconds. The microhardness values were calculated by taking the average of the microhardness values taken from the surface of the samples from five different points. The highest microhardness value is the 5% graphene added P(Ac-Kum) sample. Wear tests were carried out with a pin-on-disc wear tester under single load (10N) and in dry conditions with a total sliding distance of 10 meters and a sliding speed of 5 mm/sec. Disc samples with a diameter of 13 mm were placed in the sample holder part of the test device. The highest wear resistance sample is the P(Ac-Kum) 5% graphene composite.

Porous Copolymers of 3-(Trimethoxysilyl)propyl Methacrylate with Trimethylpropane Trimethacrylate Preparation: Structural Characterization and Thermal Degradation

Porous polymeric microspheres are among the most effective adsorbents. They can be synthesized from numerous monomers using different kinds of polymerization techniques with a broad selection of synthesis factors. The main goal of this study was to prepare copolymeric microspheres and establish the relationship between copolymerization parameters and the porosity and thermal stability of the newly synthesized materials. Porous microspheres were obtained via heterogenous radical copolymerization using 3-(trimethoxysilyl)propyl methacrylate (TMPSM) as functional monomers and trimethylolpropane trimethacrylate (TRIM) as the crosslinker. In the course of the copolymerization, toluene or chlorobenzene was used as the pore-forming diluent. Consequently, highly porous microspheres were produced. Their specific surface area was established by a nitrogen adsorption/desorption method and it was in the range of 382 m2/g to 457 m2/g for toluene and 357–500 m2/g in the case of chlorobenzene. The thermal degradation process was monitored by thermogravimetry and differential scanning calorimetry methods in inert and oxidative conditions. The copolymers were stable up to 269–283 °C in a helium atmosphere, whereas in synthetic air the range was 266–298 °C, as determined by the temperature of 5% mass loss. Thermal stability of the investigated copolymers increased along with an increasing TMPSM amount in the copolymerization mixture. In addition, the poly(TMSPM-co-TRIM) copolymers were effectively used as the stationary phase in GC analyses.

Thermomechanical and Structural Analysis of Manufactured Composite Based on Polyamide and Aluminum Recycled Material.

The paper presents an analysis of the filler's effect on the machining process and on changes in the thermomechanical properties of polymer composites based on aluminum chips. Composite research samples with a polymer matrix in the form of polyamide 6 were made by the pressing method. Comparative studies were carried out on the changes in thermomechanical properties and structure of the obtained molders with different filler contents and different fractions after the machining process. In order to determine the changes in thermal and mechanical properties, analysis was carried out using the differential scanning calorimetry (DSC) method, thermal analysis of dynamic mechanical properties (DMTA) and a detailed stereometric analysis of the surface. After mechanical processing, roughness amplitude parameters and volumetric functional parameters were determined. In order to analyze the structure, tomographic examinations of the manufactured composite were conducted. In relation to the polymer matrix, a significant increase in the storage modulus of the composites was noted in the entire temperature range of the study. An increase in the enthalpy of melting of the matrix was noted in composites with a lower filler content and a shift in the melting range of the crystalline phase. Significant differences were noted in the study of the composite surfaces in the case of using fillers obtained after machining with different fractions. The dependencies of the functional and amplitude parameters of the surfaces after machining of composite samples prove the change in the functional properties of the surface. The use of aluminum chips in the composite significantly changed the surface geometry.

Thermal transformations of graphite and anthracite in the presence of lithium carbonate

The method of differential scanning calorimetry was used to study mixtures of graphite and anthracite with lithium carbonate in an argon atmosphere and in air. It was found that in the temperature range of 100–500°C, a stronger mass loss occurs in argon than in air. This phenomenon is caused by the removal of oxygen compounds with carbon. Competing processes take place in the air – the formation of oxygen compounds with carbon, coal and desorption of oxygen-containing substances. A comparison of thermal effects on the curves of DSC and gravimetry for graphite–lithium carbonate systems in argon, in air is carried out. It was found that up to 700°C in the reaction products, the molar ratio of carbon oxides (IV; II) can be estimated at 10 : 1. Endothermic effects of lithium carbonate melting in an argon atmosphere for mixtures of graphite and anthracite with lithium carbonate were observed at 732°C and 727°C, respectively. In air, the peaks of endothermic effects do not correspond to the heat absorption curves in argon. The most probable explanations of the observed effects are given – the presence of phases of carbonate and lithium oxide; the manifestation of the stretched nature of the pre-transition region of lithium carbonate. By the method of powder X-ray diffractometry, it was found that the burnout of the carbon phase at 500°C in graphite, anthracite does not lead to a significant change in the interplane distances in lithium carbonate.

Use of differential scanning calorimetry as a rapid, effective in-process check method for impurity quantitation of an early clinical batch of Giredestrant (GDC-9545)

Giredestrant (GDC-9545) is a selective estrogen receptor degrader (SERD) that was developed for treatment of ER+/HER2− metastatic breast cancer. An anhydrous crystalline tartrate salt was identified as the solid form suitable for clinical development. An early clinical batch of the active pharmaceutical ingredient (API)/drug substance failed to pass the GMP purity specifications owing to the presence of a substantial amount of high molecular weight impurities (oligomers), as determined by size exclusion chromatography. Several trial rework batches were manufactured using various re-slurry and recrystallization conditions to purge impurities in the drug substance to adhere to purity specifications. Based on the melting point depression of the API in presence of oligomers in these rework batches, a differential scanning calorimetry method was developed to quantify impurity content as a function of melting point onset of the API. This thermal analysis method was used as a surrogate for chromatography as a rapid, effective in-process check method for impurity quantitation to enable the timely release of the final reworked clinical batch. Post release, the % w/w oligomer value determined by calorimetry was in excellent agreement to that obtained by size exclusion chromatography.

The Specificity of Determining the Latent Heat of Solidification of Cast Hypoeutectic AlSiCu Alloys Using the DSC Method.

Latent heat is commonly measured using Differential Thermal Analysis (DTA) or Differential Scanning Calorimetry (DSC) or calculated using software packages (Thermo-Calc). In this study, the DSC method was used to comprehensively evaluate the accuracy of calculated latent heat for a specific range of cast AlSiCu alloys, considering their solidification under different cooling conditions. The tests involved varying concentrations of two crucial alloying elements: wSi (5, 7, and 9%) and wCu (1, 2, and 4%). All selected alloys were analyzed under three distinct cooling/heating rates: 6, 10, and 50 °C/min. The Thermo-Calc method was used in this work to calculate the latent heats of the investigated alloys. The results obtained show good agreement between the measured and calculated values. The increase in silicon content in the investigated alloys from 4.85% to 9.85% resulted in the increase in latent heat from 407.6 kJ/kg to 467.5 kJ/kg. Higher cooling rates, such as 50 °C/min, resulted in a reduced latent heat release compared to slower rates such as 10 °C/min and 6 °C/min.

Biopharmaceutical studies of a novel sedative sublingual lozenge based on glycine and tryptophan: A rationale for mucoadhesive agent selection

Effective sedative drugs are in great demand due to increasing incidence of nervous disorders. The present work was aimed to develop a novel sublingual sedative drug based on glycine and L-tryptophan amino acids. Carbopol and different hydroxypropyl methylcellulose species were alternatively tested as mucoadhesive agents intended to prolong tryptophan sublingual release time. A model lipid medium of fully hydrated L-α-dimyristoylphosphatidylcholine was used for optimal mucoadhesive agents selection. Simultaneous processes of drug release and diffusion in lipid medium were first investigated involving both experimental and theoretical approaches. Individual substances, their selected combinations as well as different drug formulations were consecutively examined. Application of kinetic differential scanning calorimetry method allowed us to reveal a number of specific drug-excipient effects. Lactose was found to essentially facilitate tryptophan release and provide its ability to get into the bloodstream simultaneously with glycine, which is necessary to achieve glycine-tryptophan synergism. Introduction of a mucoadhesive agent into the formulation was shown to change kinetics of drug-membrane interactions variously depending on viscosity grade. Among the mucoadhesive agents, hydroxypropyl methylcellulose species K4M and E4M were shown to further accelerate drug release, therefore they were selected as optimal. Thus, effectiveness of the novel sedative drug was provided by including some excipients, such as lactose and the selected mucoadhesive agent species. A dynamic mathematical model was developed properly describing release and diffusion in lipid medium of various drug substances. Our study clearly showed applicability of a lipid medium to meet challenges such as drug-excipient interactions and optimization of drug formulations.

Structural interpretation of the viscous flow and relaxation kinetics in the As-Se and Ge-Se chalcogenide systems

This study investigates the behaviour of As₂₀Se₈₀ and Ge₂₅Se₇₅ chalcogenide glasses near the glass transition temperature using differential scanning calorimetry (DSC) and thermomechanical analysis (TMA), addressing a gap in the literature for these compositions. Precise TMA measurements of viscosity in the range of 10⁶ – 10¹³ Pa·s clarified existing data and improved the quality of fits describing the temperature-dependent viscosity for both compositions. The DSC method enabled a comprehensive analysis of structural relaxation behaviours, which were described using the Tool-Narayanaswamy-Moynihan (TNM) model with the determination of its four parameters. The study discusses the viscosity and structural relaxation behaviours of both glass-formers in relation to their structure, referencing previous results for other binary chalcogenide glasses in the As-Se and Ge-Se systems. The findings indicate significant changes in viscosity and activation energy of structural relaxation with the addition of As or Ge, while the non-linearity and non-exponentiality parameters remain largely unaffected.

Impact of mobile and stationary phases on siRNA duplex stability in liquid chromatography

Nucleic acid duplexes are typically analyzed in non-denaturing conditions. Melting temperature (Tm) is the property used to measure duplex stability; however, it is not known how the chromatographic conditions and mobile phase composition affect the duplex stability. We employed differential scanning calorimetry (DSC) method to measure the melting temperature of chemically modified silencing RNA duplex (21 base pairs, 0.15 mM duplex concentration) in mobile phases commonly used in reversed-phase, ion-pair reversed-phase, size exclusion and hydrophilic interaction chromatography. We investigated mobile phases consisting of ammonium acetate, alkylammonium ion-pairing reagents, alkali-ion chlorides, magnesium chloride, and additives including methanol, ethanol, acetonitrile and hexafluoroisopropanol. Increasing buffer concentration enhanced the duplex stability (Tm was 67.1 – 78.2 °C for 10–100 mM [Na+] concentration). The melting temperature decreases with the increase in cation size (70.2 °C in 10 mM [Li+], 68.1 °C in 10 mM [NH4+], 65.6 °C in 10 mM [Cs+], and 56.6 °C in 10 mM [triethylammonium+] solutions). Inclusion of 20 % of organic solvent in buffer reduced the melting temperature by 1–3 °C, and denaturation power increases in the order MeOH<EtOH<MeCN. Next, we investigated the RNA duplex melting using selected chromatographic techniques and within the 10–90 °C column temperature range. Melting temperature obtained with size exclusion chromatography in 25 mM sodium phosphate buffer was ∼ 70 °C, about 5 °C lower compared to DSC values. The apparent melting temperature for a reversed-phase chromatography experiment was < 10 °C for 10 mM ammonium acetate mobile phase with acetonitrile eluent. Ion-pair reversed-phase with 10 mM triethylamine, 100 mM hexafluoroisopropanol and MeCN as eluent yielded Tm 49.3–54.9 °C. Hydrophilic interaction chromatography experiments with 10 mM ammonium acetate and ∼ 50 % acetonitrile mobile phase showed high duplex stability (Tm ∼ 80 °C). The observed chromatographic Tm values suggest that the formation of an organic/aqueous solvent layer on the chromatographic sorbent surface affects the duplex stability more significantly than the composition of the mobile phase alone.

Modifying Membranotropic Action of Antimicrobial Peptide Gramicidin S by Star-like Polyacrylamide and Lipid Composition of Nanocontainers.

Gramicidin S (GS), one of the first discovered antimicrobial peptides, still shows strong antibiotic activity after decades of clinical use, with no evidence of resistance. The relatively high hemolytic activity and narrow therapeutic window of GS limit its use in topical applications. Encapsulation and targeted delivery may be the way to develop the internal administration of this drug. The lipid composition of membranes and non-covalent interactions affect GS's affinity for and partitioning into lipid bilayers as monomers or oligomers, which are crucial for GS activity. Using both differential scanning calorimetry (DSC) and FTIR methods, the impact of GS on dipalmitoylphosphatidylcholine (DPPC) membranes was tested. Additionally, the combined effect of GS and cholesterol on membrane characteristics was observed; while dipalmitoylphosphatydylglycerol (DPPG) and cerebrosides did not affect GS binding to DPPC membranes, cholesterol significantly altered the membrane, with 30% mol concentration being most effective in enhancing GS binding. The effect of star-like dextran-polyacrylamide D-g-PAA(PE) on GS binding to the membrane was tested, revealing that it interacted with GS in the membrane and significantly increased the proportion of GS oligomers. Instead, calcium ions affected GS binding to the membrane differently, with independent binding of calcium and GS and no interaction between them. This study shows how GS interactions with lipid membranes can be effectively modulated, potentially leading to new formulations for internal GS administration. Modified liposomes or polymer nanocarriers for targeted GS delivery could be used to treat protein misfolding disorders and inflammatory conditions associated with free-radical processes in cell membranes.

Early-Stage Evaluation of Battery Safety Based on Materials, Component, and Microcell Calorimetry Measurements

There are numerous “beyond lithium ion” battery chemistries under development at universities, national labs, companies, and other organizations. Early-stage battery chemistry work typically focuses on demonstrating performance at the materials, coin, and pouch cell level, with evaluation and design for safety left for later stages.1 In this talk, we will describe the opportunities for assessing the safety of a battery chemistry at the earliest stages of its development, as soon as the active materials and electrolyte have been identified.2 With carefully designed and quantitative experiments, key information such as the amounts of heat released by the reactions of and among cell components, the temperatures at which that heat is released, the release of toxic or otherwise dangerous gases, the material heat capacities, and other key properties can be measured with differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and other approaches. We have demonstrated the value of this approach for a LixCoO2+C+PVDF cathode sheet /LLZO/Li metal material set, where we identified the previously under-appreciated role of the cathode sheet conductive additive and binder in the reaction pathways upon heating to 500°C in a DSC pan.3 Despite this material set containing no liquid electrolyte, delithiated LixCoO2 releases oxygen upon heating to >~230°C, and that oxygen can react exothermically with the Li metal and conductive carbon. In addition, PVDF binder releases HF gas at >400°C, which can also react exothermically with Li metal.This talk will focus on the methodology required to obtain accurate measurements on milligram-scale samples, with an emphasis on the sample preparation and DSC methods to obtain accurate, repeatable results. Approaches associated with DSC baselining and integration methods will be presented. The talk will also present results from our recent work on material sets that are more commercially relevant for electric vehicle applications than the LixCoO2 cathode sheet/ LLZO / Li material set. In particular, results from material sets such as NMC532 cathode sheet / LLZO / Li, NMC811 cathode sheet / LLZO / Li, and NMC811 cathode sheet / LPSCl / Li metal will be presented. Finally, we will discuss the implications of our early-stage, material-scale work for future large-format cells.1. See Category 3 in the ARPA-E EVS4ALL program, https://arpa-e.energy.gov/technologies/programs/evs4all2. Joule 6, 742–755, April 20, 2022.3. ACS Appl. Mater. Interfaces 2023, 15, 49, 57134–57143

A Study of Hydroxyl-Terminated Block Copolyether-Based Binder Curing Kinetics.

In order to determine the curing reaction model and corresponding parameters of hydroxyl-terminated block copolyether (HTPE) and provide a theoretical reference for its practical application, the non-isothermal differential scanning calorimetry (DSC) method was used to analyze the curing processes of three curing systems with HTPE and N-100 (an aliphatic polyisocyanate curing agent), isophorone diisocyanate (IPDI), and a mixture of N-100 and IPDI as curing agents. The results show that the curing activation energy of N-100 and HTPE was about 69.37 kJ/mol, slightly lower than the curing activation energy of IPDI and HTPE (75.60 kJ/mol), and the curing activation energy of the mixed curing agent and HTPE was 69.79 kJ/mol. The curing process of HTPE conformed to the autocatalytic reaction model. The non-catalytic reaction order (n) of N-100 and HTPE was about 1.2, and the autocatalytic order (m) was about 0.3, both lower than those of IPDI and HTPE. The reaction kinetics parameters of the N-100 and IPDI mixed curing agent with HTPE were close to those of N-100 and HTPE. The verification results indicate a high degree of overlap between the experimental data and the calculated data.

Repercussion of fiber content on the mechanical, thermal, and thermomechanical properties of natural fibers reinforced thermoplastic composites for automotive application

Natural fibers are becoming very popular as a reinforcement in composite materials owing to their benefits, such as low-price, lightweight, availability, and environmental friendliness. In this study, abaca fiber-reinforced polypropylene (PP) and high-density polyethylene (HDPE) composites were created with the help of the injection molding method. Prior to composite fabrication, abaca fibers were chemically treated with a 5 wt% caustic soda (NaOH) solution to improve the bonding between the abaca fibers and the matrix and to enhance their properties. Scanning electron microscopy (SEM) was utilized to assess the fiber surface microstructures before as well as after the chemical treatment, along with the fractured surfaces of tensile specimens. The mechanical properties, such as tensile, bending, and impact strength, of abaca/PP and abaca/HDPE composites were evaluated and compared. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) methods were utilized to investigate the thermal behavior of composites. Also, the dynamic mechanical analysis (DMA) method was utilized to explore the thermomechanical properties of the fabricated composites. The outcomes of the experimental findings showed that abaca/PP composite with 10 and 20 wt% fibers is the best choice of material to be used in the automobile industry.