Thermogravimetric Analysis Research Articles

Effect of silicone monomers on the properties of fluorinated acrylate pressure-sensitive adhesive for ePTFE bonding

Purpose Silicon-containing groups were introduced into fluoroacrylate polymer to further improve the comprehensive performance of pressure-sensitive adhesive (PSA) for expanded polytetrafluoroethylene (ePTFE) bonding. Design/methodology/approach A series of silicon-containing fluorinated acrylic copolymers were synthesized through free radical solution polymerization with vinyloxy trimethylsilane, allyltrimethylsilane, 3-(trimethoxysilyl)propyl methacrylate or 1,3,5-tris(3,3,3-trifluoropropyl) methylcyclotrisiloxane as silicon monomers, and comprehensive performance of the copolymers was evaluated based on Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), gel permeation chromatography, glass transition temperatures (Tg), differential scanning calorimetry, thermogravimetric analysis, water contact angle, the track, 180° peel strength, and shear holding power. Findings Based on the FTIR and XPS results, it is confirmed that the silicon monomers were successfully introduced into the fluorinated acrylate copolymer. XPS analysis indicated that the silicon groups had the tendency to enrich on the surface of the film, thereby reducing the F content on the film surface. The glass transition temperatures (Tg) of the PSAs increased when silicon monomers were introduced, while the thermal stability declined. The contact angles of the acrylic PSA films were increased with the introduction of silicon monomers. From the perspective of bonding performance, the track, 180° peel strength and shear holding power decreased to varying degrees compared to silicon-free PSA, except significantly elevated holding power with MPS as the silicon monomer. Originality/value Silicon-containing fluorinated acrylic copolymers were synthesized, and the comprehensive performance was evaluated as PSAs of ePTFE for the first time.

Synthesis of P(AM/AA/SSS/DMAAC-16) and Studying Its Performance as a Fracturing Thickener in Oilfields

In order to solve the problems of long dissolution and preparation time, cumbersome preparation, and easy moisture absorption and deterioration during storage or transportation, acrylamide (AM), acrylic acid (AA), sodium p-styrene sulfonate (SSS), and cetyl dimethylallyl ammonium chloride (DMAAC-16) were selected as raw materials, and the emulsion thickener P(AM/AA/SSS), which can be instantly dissolved in water and rapidly thickened, was prepared by the reversed-phase emulsion polymerization method. DMAAC-16, the influence of emulsifier dosage, oil–water ratio, monomer molar ratio, monomer dosage, aqueous pH, initiator dosage, reaction temperature, reaction time, and other factors on the experiment was explored by a single-factor experiment, and the optimal process was determined as follows: the oil–water volume ratio was 0.4, the emulsifier dosage was 7% of the oil phase mass, the initiator dosage was 0.03% of the total mass of the reaction system, the reaction time was 4 h, the reaction temperature was 50 °C, the aqueous pH was 6.5, and the monomer dosage was 30% of the total mass of the reaction system (monomeric molar ratio n(AM):n(AA):n(SSS):n(DMAAC-16) = 79.2:20:0.5:0.3). X-ray diffraction analysis (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy analysis were carried out on the polymerization products. At the same time, a series of performance test experiments such as thickening performance, temperature and shear resistance, salt resistance, sand suspension performance, core damage performance, and fracturing fluid flowback fluid reuse were carried out to evaluate the comprehensive effect and efficiency of the synthetic products, and the results show that the P(AM/AA/SSS/DMAAC-16) polymer had excellent solubility and excellent properties such as temperature and shear resistance.

Silver and Titanium Oxides Coated on g-C3N4 Nanocomposite for Photocatalytic Degradation of Mixture of Brilliant Green-Congo Red Dyes and Ciprofloxacin Antibiotic Under Visible Light Irradiation

Silver and titanium oxides coated graphitic carbon nitride (Ag2O/TiO2/g-C3N4) nanocomposite was created by a single-step thermal polymerization. The Fourier Transform infrared (FT-IR), UV-visible absorption spectroscopy (UV-vis), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) methods, thermal gravimetric analysis (TGA), photoluminescence (PL), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were within the numerous techniques used to characterize this nanocomposite. Both the photoluminescence (PL) spectrum and the Tauc plot indicated that the Ag2O/TiO2/g-C3N4 nanocomposite had a lower electron-hole pair recombination rate and lower band gap energy. The coating of Ag2O and TiO2 on g-C3N4 was verified by TEM. The Ag2O/TiO2/g-C3N4 nanocomposite was used in the photocatalytic degradation of a Brilliant green (BG)-Congo red (CR) dye combination and ciprofloxacin (CIP) antibiotic under visible light irradiation. According to the research, under visible light irradiation, the Ag2O/TiO2/g-C3N4 nanocomposite photocatalytic activity simultaneously degraded a mixture of BG-CR dyes, with BG (93%) and CR (85%) degrading percentages in 70 min and CIP (82%) degrading in 120 min. Superoxide and hydroxyl radicals were primarily responsible for the degradation of BG and CR dyes under visible light irradiation, whereas holes and hydroxyl radicals were investigated as important oxidative species in the photocatalytic degradation of CIP utilizing the Ag2O/TiO2/g-C3N4 nanocomposite.Graphical

Synthesis and Characterization of DOPO Modified Tetraglycidyl Eugenol Cyclic Siloxane Resins Cured with Tannic Acid

AbstractIn this work, a tetra glycidyl eugenol cyclic siloxane resin (TGED4) is synthesized, then further modified with 9,10‐dihydro‐9‐oxa‐10‐phosphaphenathrene‐10‐oxide (DOPO) to produce Si and P epoxy resins. After blending with diglycidyl ether of bisphenol A (DGEBA) and curing with tannic acid (TA), high performance, fire‐retardant polymer networks are created. Near infrared spectroscopy (NIR) confirms the networks are highly cured and have low extractable content, while dynamic mechanical thermal analysis (DMTA) displays a lower Tg and heterogeneous network with increasing DOPO. The networks display a maximum improvement in flexural modulus, strength, and strain to failure of 20.6%, 55.5%, and 78.8% respectively, and at 65.4 MPa strength and 2.8 GPa modulus are comparable to high‐performance networks. Thermogravimetric analysis (TGA) shows that increasing P reduces thermal stability, but contributes to higher char yield despite lower Si. The fire retardancy improve markedly measured via limiting oxygen index (LOI), increasing from 26.5% to a maximum of 35.5%, while V‐0 behavior is readily achieved at the lowest DOPO content. Cone colorimetry further reduces peak heat release rate (PHHR) and total heat release rate (THHR) by 28% and 42%. This work presents hybrid bio‐derived epoxy resins with excellent fire retardancy and good mechanical properties.

From the end to the beginning: Obtaining and evaluation of flexible PVC produced via chemical recycling of post-consumer PET

Di(2-ethylhexyl) terephthalate (DEHTP) is a promising substitute for dioctyl phthalate (DOP, banned in certain countries) as a polyvinyl chloride (PVC) plasticizer. This research endeavors to present findings about the synthesis of DEHTP through the depolymerization of polyethylene terephthalate (PET) with 2-ethyl-1-hexanol, the production and assessment of PVC formulated with this plasticizer, and a comparative analysis with PVC compounded using commercial plasticizers (DOP and DEHTP). Approximately 200 post-consumer PET bottles underwent chemical recycling under various conditions, leading to complete depolymerization (99%) following a six-hour reaction at 300°C. The plasticizers were characterized by infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, and gas chromatography coupled to mass spectrometry. The flexible PVCs were tensile and hardness tested and submitted to dynamic mechanical and thermogravimetric analyses. The resulting plasticizer exhibited properties analogous to commercial DEHTP, producing flexible PVC with even better properties. For instance, the activation energy of the dehydrochlorination reaction of the flexible PVC produced with DHETP from depolymerization was 3.3% to 16.2% higher than those produced with commercial plasticizers.

Enhanced MICP for Soil Improvement and Heavy Metal Remediation: Insights from Landfill Leachate-Derived Ureolytic Bacterial Consortium

This study investigates the potential of microbial-induced calcium carbonate precipitation (MICP) for soil stabilization and heavy metal immobilization, utilizing landfill leachate-derived ureolytic consortium. Experimental conditions identified yeast extract-based media as most effective for bacterial growth, urease activity, and calcite formation compared to nutrient broth and brown sugar media. Optimal MICP conditions, at pH 8–9 and 30 °C, supported the most efficient biomineralization. The process facilitated the removal of Cd2+ (99.10%) and Ni2+ (78.33%) while producing stable calcite crystals that enhanced soil strength. Thermal analyses (thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)) confirmed the successful production of CaCO3 and its role in improving soil stability. DSC analysis revealed endothermic and exothermic peaks, including a significant exothermic peak at 444 °C, corresponding to the thermal decomposition of CaCO3 into CO2 and CaO, confirming calcite formation. TGA results showed steady weight loss, consistent with the breakdown of CaCO3, supporting the formation of stable carbonates. The MICP treatment significantly increased soil strength, with the highest surface strength observed at 440 psi, correlating with the highest CaCO3 content (18.83%). These findings underscore the effectiveness of MICP in soil stabilization, pollutant removal, and improving geotechnical properties.

Utilization of Thermal-Activated Coal Gangue to Enhance the Properties of Sandy Soil Composites

To effectively solve the problem of land sanding and improve the water- and element-retaining properties of sandy soil, a thermal-activated coal gangue (TACG) was used as an ameliorating material to prepare a composite soil mixed with sandy soil to enhance the water-retaining and fertilizer-fixing properties of the sandy soil and reduce the evaporation of water in the soil. The structure and thermal stability of the gangue were characterized using Fourier transform infrared spectroscopy and thermogravimetric analysis. By applying different dosages and different calcination temperatures of the TACG, the water-holding capacity of the mixed soil was determined, and changes in pore structure were observed. When the dosage was 15% and the calcination temperature was 600 °C, the mixed soil possessed the most excellent distribution of pore structure and could effectively prevent water evaporation. Meanwhile, the application of the TACG in sandy soil improved its adsorption of K+, which showed the potential application of thermally activated gangue materials in the field of soil improvement.

Investigation of chitin grafting: thermal, antioxidant and antitumor properties

In this study, firstly chitin was reacted with chloracetyl chloride to synthesize the macroinitiator chitinchloroacetate (Ch.ClAc). Then, graft copolymers of methacrylamide (MAM), diacetone acrylamide (DAAM), N-(4-nitrophenyl)acrylamide (NPA), and 2-hydroxyethyl methacrylate (HEMA) monomers were synthesized by atom transfer radical polymerization (ATRP). All of the polymers were characterized by FTIR spectra and elemental analysis. According to the elemental analysis results, the mole percent (y) of the macro initiator was found to be 17.39%. The thermal stability of all the polymers (chitin, Ch.ClAc and its graft copolymers) was determined by thermogravimetric analysis (TGA) method and the highest thermal stability was observed in the ungrafted raw chitin. DPPH• scavenging activity and antitumor activity of all polymers were then investigated. Ch.ClAc was found to be the polymer that inhibited the proliferation of tumor cells more than chitin and graft copolymers. It was observed that the antitumor (L1210 cell lines) effect increased with increasing time and concentration in all polymers.

Application of Κ-Carrageenan for One-Pot Synthesis of Hybrids of Natural Curcumin with Iron and Copper: Stability Analysis and Application in Papilloscopy

In this study, hybrid materials were synthesized incorporating curcumin, Cu2+ or Fe3+, and Kappa-carrageenan as a reducing agent to improve stability, considering that curcumin has low thermal and solution stability, which limits its applications. Colorimetric analysis showed color changes in the hybrids, ultraviolet–visible spectroscopy revealed band shifts in the hybrids, and infrared analysis indicated shifts in wavenumbers, suggesting changes in the vibrational state of curcumin after bonding with metal ions. These techniques confirmed the formation of hybrid materials. Thermogravimetric and chromatographic analyses demonstrated greater thermal and solution stability for the hybrids compared to curcumin. Additionally, the hybrid composites effectively developed natural and sebaceous latent fingerprints with good clarity and contrast on glass surfaces. Both composites performed similarly to commercial Gold® powder. When applied to surfaces representative of forensic scenarios, the composites were versatile, revealing sufficient fingerprint details for human identification on both porous and non-porous surfaces. Scanning electron microscopy images showed greater clarity in sebaceous and natural fingerprints developed with the Fe composite compared to the Cu composite.

Comparison of Two Synthesis Methods for 3D PLA-Ibuprofen Nanofibrillar Scaffolds

Objectives: This study aimed to synthesize polylactic acid (PLA) nanofibrillar scaffolds loaded with ibuprofen (IBU) using electrospinning (ES) and air-jet spinning (AJS). The scaffolds were evaluated for their physicochemical properties, drug release profiles, and biocompatibility to assess their potential for local analgesic applications. Methods: Solutions of 10% (w/v) PLA combined with IBU at concentrations of 10%, 20%, and 30% were processed into nanofibrillar membranes using ES and AJS. The scaffolds were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier-transformed infrared (FT-IR) spectroscopy. The drug release profile was assessed by ultraviolet-visible spectrophotometry (UV-Vis), and cell adhesion and viability were evaluated using fibroblast culture assays. Statistical analyses included qualitative analyses, t-tests, and Likelihood ratio tests. Results: SEM revealed randomly arranged nanofibers forming reticulated meshes, with more uniform dimensions observed in the AJS group. TGA and DSC analyses confirmed the thermodynamic stability of the scaffolds and enthalpy changes consistent with IBU incorporation, which FT-IR and UV-Vis validated. Drug release was sustained over 384 h, showing no significant differences between ES and AJS scaffolds (p > 0.05). Cytotoxicity and cell viability assays confirmed scaffold biocompatibility, with cellular responses proportional to drug concentration but within safe limits. Conclusions: PLA-IBU nanofibrillar scaffolds were successfully synthesized using ES and AJS. Both methods yielded biocompatible systems with stable properties and controlled drug release. Further, in vivo studies are necessary to confirm their clinical potential.

Design and Synthesizing of Hemoglobin-Based Multifunctional Fibers for Improved Carbon Monoxide Absorption Rates

This study is aimed at developing advanced materials for carbon monoxide (CO) capture by producing hemoglobin (Hb)-based electrospun multifunctional micro- and nanofibers blended with polyvinylpyrrolidone (PVP). Unlike conventional CO trapping materials such as activated carbon, ammoniacal cuprous chloride, zeolites, and metal-organic frameworks (MOFs), Hb/PVP fibers leverage the simplicity and scalability of electrospinning to produce continuous, defect-free flexible fibers with tunable micron- to nanoscale diameters. The process enables precise control over fiber morphology, surface area, porosity, and hydrophilicity, providing significant advantages for optimizing CO adsorption rates. Moreover, the inclusion of Hb introduces a biomimetic advantage through its intrinsic CO-binding affinity, offering higher specificity and interaction potential compared to traditional physical adsorption or chemical frameworks. Experimental results revealed that fibers with 8 wt.% PVP exhibited the smallest and most uniform diameters, while higher PVP concentrations (16, 32 wt.%) enhanced hydrophilicity, with complete water absorption occurring within 400 and 200 seconds, respectively. Structural and compositional analyses using confocal laser scanning microscopy (CLSM) and Fourier transform infrared spectroscopy (FTIR) confirmed the integrity and chemical characteristics of the fibers. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) established their thermal stability, with critical transitions at approximately 80 ℃ (denaturation) and 200 ℃ (decomposition). Degradation was observed between 200 and 430 ℃, corresponding to significant weight loss. These findings demonstrate the potential of Hb/PVP fibers as exceptional alternatives for CO capture. This study may open new possibilities for increasing the absorption rate of highly porous fibers for toxic CO capture in the bloodstream and address other related concerns.

Biocrude production via hydrothermal liquefaction of cycas circinalis seed shell: A machine learning approach

ABSTRACT Hydrothermal liquefaction (HTL) is a promising thermochemical method for converting biomass into bio-crude fuel. This study explores the HTL of Cycas circinalis seed shell (CSS), focusing on the impacts of reaction time, feed slurry concentration, and temperature on bio-crude yield. Experiments were conducted at temperatures ranging from 250 to 375°C, reaction times from 10 to 40 minutes, and feed slurry concentrations between 10% and 30%. A decision tree regression (DTR) model predicted the optimal bio-crude yield of 35% at 375°C, 30% feed slurry concentration, and 40 minutes, with high accuracy (R² = 0.9853, RMSE = 0.992). Results highlight temperature and time as key factors influencing bio-crude production.The bio-crude was characterized using Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), nuclear magnetic resonance (NMR), and gas chromatography-mass spectrometry (GC-MS). Degradation kinetics of bio-crude and CSS biomass were analyzed using the Coats-Redfern method at heating rates of 5, 10, and 20°C/min. Parameters such as activation energy (E), rate constant, pre-exponential factor (A), enthalpy, entropy, and Gibbs free energy were determined. This research advances hydrothermal technology and promotes the development of sustainable and efficient biomass conversion processes.

Electrochemical Sensor Based on CoMgFe-Trimetallic Layered Double Hydroxides for Flubendiamide Detection in Water Samples

Abstract Flubendiamide (FBD) is a widely used insecticide in agriculture, known for its effectiveness in controlling crop pests. However, its use presents significant risks to both the environment and human health. In this study, a novel pencil graphite electrode (PGE) was successfully modified with CoMgFe trimetallic layered double hydroxides (CoMgFe-TLDHs) to achieve sensitive and selective electrochemical detection of 20% FBD, a toxic insecticide posing ecological and health concerns. The CoMgFe-TLDHs were synthesized using a simple co-precipitation method and characterized by thermogravimetric differential thermal analysis, X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. These materials were then applied to the PGE surface, significantly enhancing its electrochemical performance, as demonstrated by differential pulse voltammetry and cyclic voltammetry. Under optimized conditions, PGE/ionic liquid/CoMgFe-TLDHs electrode exhibited excellent analytical properties toward FBD determination. A calibration curve was well-established from 0.8 to 100 µM for FBD with a detection limit of 0.36 μM. The proposed sensor enabled the practical application of sensitive FBD detection in tape and river water with good recovery rates.

Microwave Synthesis of Butyl Levulinate Using a Keggin Heteropolyacid from Eichhornia crassipes Cellulose Obtained by Pretreatment with Bacillus sp.

Underutilized lignocellulosic biomass, such as aquatic plants, faces sustainability challenges due to energy-intensive treatments. This study investigates the use of Bacillus sp. for the biological pretreatment of water hyacinth (Eichhornia crassipes) aiming to improve the efficiency of alkyl levulinate (AL) production, which are valuable compounds used as fuel additives, solvents, and plasticizers. The pretreatment with Bacillus sp. resulted in stable bacterial growth and a significant increase in cellulose content (up to 27%) compared to untreated samples. X-ray diffraction revealed a higher crystallinity index (63%) in the treated cellulose, while morphological analysis confirmed microbial degradation. Thermogravimetric analysis showed improved thermal stability, consistent with the higher crystallinity, and FTIR spectra indicated successful delignification. The microwave-assisted synthesis of butyl levulinate yielded 30% from Bacillus sp.-treated cellulose, compared to 11% from untreated cellulose, highlighting the potential for biomass valorization through biological pretreatment.

Fly Ash Polymer Composites Enhancing Pore Refinement and Sulphate Resistance in Cement

Fly ash has also become quite renowned as an important by-product material from the combustion of coal it finds various applications as an additive to both polymer composites and cementitious systems, primarily enhancing their mechanical properties including compressive strength, wear resistance, and resistance against sulphate penetration as well as reduced porosity resulting from pozzolanic reactions. This review focuses on the synthesis, characterization, and diversified applications of fly ash polymer composites, which include pore refinement and long-term stability. Advanced analytical techniques, such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA), are essential in understanding the microstructure and hydration mechanisms of these composites.

In Situ Synthesis of Zr-Doped Mesoporous Silica Based on Zr-Containing Silica Residue and Its High Adsorption Efficiency for Methylene Blue

Zr-containing silica residue (ZSR) is an industrial by-product of ZrOCl2 production obtained through an alkali fusion process using zircon sand. In this study, low-cost and efficient Zr-doped mesoporous silica adsorption materials (Zr-MCM-41 and Zr-SBA-15) were prepared in one step via the hydrothermal synthesis method using ZSR as the silicon source for the removal of methylene blue (MB) from dye-contaminated wastewater. The samples were characterized using X-ray fluorescence (XRF) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry (TG), and N2 adsorption–desorption measurements. The findings indicate that the synthesized Zr-MCM-41 and Zr-SBA-15 possess highly ordered mesoscopic structures with high specific surface areas of 910 and 846 m2/g, large pore volumes of 1.098 and 1.154 cm3/g, and average pore diameters of 4.18 and 5.35 nm, respectively. The results of the adsorption experiments show that the adsorbent has better adsorption properties under alkaline conditions. The adsorption process obeys the pseudo-quadratic kinetic model and the Freundlich adsorption isotherm model, indicating the coexistence of physical and chemisorption processes. The maximum adsorption capacities of Zr-MCM-41 and Zr-SBA-15 are 618.43 and 516.58 mg/g, respectively, as calculated by the Langmuir model (pH = 9, temperature of 25 °C). Compared with mesoporous silica prepared with sodium silicate as the silicon source, Zr-MCM-41 and Zr-SBA-15 have different structural properties and better adsorption properties due to Zr doping. These findings indicate that ZSR is the preferred silicon source for preparing mesoporous silica, and the mesoporous silica prepared using Zr silicon slag is a promising adsorbent and has great application potential in wastewater treatment.

Effect of Dy3+ Ions on Structural, Thermal and Spectroscopic Properties of L-Threonine Crystals: A Visible Light-Emitting Material

In this study, L-threonine crystals (L-thr) containing Dy3+ ions (L-thrDy5 and L-thrDy10) with varying mass concentrations (5% and 10%) were successfully synthesized using a solvent slow evaporation method. The structural properties were characterized by Powder X-ray diffraction and Rietveld refinement. The data revealed that all three samples crystallized in orthorhombic symmetry (P212121-space group) and presented four molecules per unit cell (Z = 4). However, the addition of Dy3+ ions induced a dilation effect in the lattice parameters and cell volume of the organic structure. Additionally, the average crystallite size, lattice microstrain, percentage of void centers, and Hirshfeld surface were calculated for the crystals. Thermogravimetric and differential thermal analysis experiments showed that L-thr containing Dy3+ ions are thermally stable up to 214 °C. Fourier transform infrared and Raman spectroscopy results indicated that the Dy3+ ions interact indirectly with the L-thr molecule via hydrogen bonds, slightly affecting the crystalline structure of the amino acid. Optical analysis in the ultraviolet–visible region displayed eight absorption bands associated with the electronic transitions characteristic of Dy3+ ions in samples containing lanthanides. Furthermore, L-thrDy5 and L-thrDy10 crystals, when optically excited at 385 nm, exhibited three photoluminescence bands centered around approximately 554, 575, and 652 nm, corresponding to the 4F7/2 → 6H11/2, 4F9/2 → 6H13/2, and 4F9/2 → 6H11/2 de-excitations. Therefore, this study demonstrated that L-thr crystals containing Dy3+ ions are promising candidates for the development of optical materials due to their favorable physical and chemical properties. Additionally, it is noteworthy that the synthesis of these systems is cost-effective, and the synthesis method used is efficient.

High-Resolution TG-TOFMS Coupled with Principal Component Analysis and Kendrick Mass Defect Analysis: Elucidation of Molecular-Scale Degradation Behavior of Glass Fiber Reinforced Polypropylene during Thermo-Oxidative Degradation.

This study presents a novel approach that combines thermogravimetric analysis with time-of-flight mass spectrometry (TG-TOFMS), principal component analysis (PCA), and Kendrick mass defect (KMD) analysis─referred to as TG-PCA-KMD─to investigate molecular-scale structural changes and quantitatively assess the progression of thermo-oxidative degradation in glass fiber reinforced polypropylene (GF/PP). TG-TOFMS enables the simultaneous and sensitive detection of both structural changes due to thermo-oxidative degradation and compositional changes in the filler and matrix. PCA and KMD analysis are crucial for identifying specific ion series derived from the degraded PP matrix in the high-resolution mass spectra obtained through TG-TOFMS. Additionally, PCA fitting was employed to selectively extract information on the degraded components of GF/PP from differential thermogravimetric profiles. Our findings demonstrate the advantages and utility of TG-PCA-KMD in the degradation analysis of composite materials.

Effect of Preparation Conditions of Fe@SiO2 Catalyst on Its Structure Using High-Pressure Activity Studies in a 3D-Printed SS Microreactor

Fischer–Tropsch synthesis (FTS) in a 3D-printed stainless steel (SS) microchannel microreactor was investigated using Fe@SiO2 catalysts. The catalysts were prepared by two different techniques: one pot (OP) and autoclave (AC). The mesoporous structure of the two catalysts, Fe@SiO2 (OP) and Fe@SiO2 (AC), ensured a large contact area between the reactants and the catalyst. They were characterized by N2 physisorption, H2 temperature-programmed reduction (H2-TPR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron microscopy (XPS), and thermogravimetric analysis–differential scanning calorimetry (TGA-DSC) techniques. The AC catalyst had a clear core–shell structure and showed a much greater surface area than that prepared by the OP method. The activities of the catalysts in terms of FTS were studied in the 200–350 °C temperature range at 20-bar pressure with a H2/CO molar ratio of 2:1. The Fe@SiO2 (AC) catalyst showed higher selectivity and higher CO conversion to olefins than Fe@SiO2 (OP). Stability studies of both catalysts were carried out for 30 h at 320 °C at 20 bar with a feed gas molar ratio of 2:1. The Fe@SiO2 (AC) catalyst showed higher stability and yielded consistent CO conversion compared to the Fe@SiO2 (OP) catalyst.

Experimental Study on Thermal Properties and Fire Risk According to Acid Value Change in Palm Oil

(1) Background: this study investigates the impact of acid value changes on the thermal degradation and fire risks of palm oil. It emphasizes the need for systematic risk management in food manufacturing and preparation processes to address safety challenges associated with high-temperature operations. (2) Methods: the study employed fire reproduction experiments, fire risk characterization tests, and thermal analyses, including differential scanning calorimetry and thermogravimetric analysis. (3) Result: higher acid values in palm oil significantly reduce smoke points, ignition points, and thermal stability, primarily due to increased free fatty acids and oxidative by-products. These effects are more pronounced in oxidative environments, highlighting the importance of controlling acid value to mitigate fire and thermal risks. (4) Conclusions: this study concludes that increased acid value in palm oil significantly reduces its thermal stability and elevates fire risks due to accelerated oxidation and thermal decomposition. It emphasizes the importance of monitoring acid value and implementing temperature control measures to enhance safety in food manufacturing and cooking processes.