Thermogravimetric Analysis Research Articles

Fabrication of Three‐Dimensional Net‐Structured Polyvinyl Alcohol Nanofibers Using Spray‐Freeze‐Drying Technique

ABSTRACTPolyvinyl alcohol (PVA) nanofibers have potential importance in industrial applications. In this study, three‐dimensional (3D) net‐structured PVA nanofibers are successfully fabricated using the spray‐freeze‐drying (SFD) technique for the first time. At first, different concentrations of PVA solutions from 0.001 to 5 wt% are applied to prepare PVA nanofibers using liquid nitrogen at −196°C by the SFD method. These nanofibers are characterized by scanning electron microscopy for morphological analysis, photo ruler software for diameter measurement, thermogravimetric analysis and differential scanning calorimetry for thermal stability and crystallinity, as well as nitrogen adsorption isotherms and pore size distribution curves for specific surface area and porous surface quality. Prepared SFD nanofibers with finer nano diameters, fewer beads, more regular 3D net‐structures and without any massive blocks are obtained from 0.05 to 1 wt%. These are compared with the nanofibers prepared by the freeze‐drying (FD) technique. The SFD method shows better results than the FD method in respect to fiber morphology, finer nanoscale diameter, crystallinity, specific surface area, and surface porous property. The best results are obtained from the nanofibers fabricated by the SFD method at 0.1 wt% concentration. Finally, the findings of this work open the opportunities for potential industrial applications and further development of PVA nanofibers.

Effectively eliminating lead and cadmium from industrial wastewater using a biowaste-based sorbent

Toxic heavy metals, such as Pb(II) and Cd(II), pose serious environmental and health risks, stressing the urgent demand for innovative and sustainable techniques to reduce their adverse effects. This study investigates the use of sugar beet biowaste as an eco-friendly biosorbent for the removal of Pb(II) and Cd(II) from aqueous solutions, in both laboratory and industrial effluents. Characterization through scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, Fourier-transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy revealed the formation of stable hydrocerussite and otavite, confirming chemisorption. Approximately 95% of the employed biowaste is composed of calcium (Ca), carbon (C), and oxygen (O). The zeta potential was measured at − 17.5 mV with a point of zero charge at pH 8.0, and the total surface area of the biosorbent was approximately 7.72 m2 g−1, with a Langmuir surface area of 11.563 m2 g−1 and a pore volume of 0.028 cm3 g−1. Various parameters, such as the metal concentration, biosorbent dosage, pH, temperature, and contact time, were optimized, achieving maximum removal of Pb(II) and Cd(II) within 60 min at pH 12 and 328 K. Sorption followed a pseudo-second-order kinetic model (R2 = 0.99) and the Freundlich isotherm (R2 = 0.98), with high sorption capacities of 466.5 mg g−1 for Pb(II) and 505.6 mg g−1 for Cd(II). Thermodynamic analysis indicated that the sorption process is spontaneous, thermodynamically favorable, and endothermic. The biowaste effectively removed heavy metals and demonstrated removal efficiencies exceeding 85% for most heavy metals in industrial effluent samples from Alexandria and Ain Sokhna. Sorption capacity ratio values close to 1 indicate effective Pb(II) and Cd(II) uptake with minimal interference, even in the presence of methylene blue dye. Comparative analysis revealed that the untreated biosorbent was more efficient than typical biosorbents, and an economic cost evaluation revealed that processing the biosorbent costs 1.05 USD/kg, highlighting its potential as a sustainable and economically viable option for industrial effluent treatment and supporting broader environmental goals.

Effective removal of heavy metal ions (Pb, Cu, and Cd) from contaminated water by limestone mine wastes

Limestone mining waste and its derived CaO were checked as an adsorbents of pb2+, Cu2+, and Cd2+ ions from water solution. The characterization of Limestone and calcined limestone was studied by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Scanning Electron Microscope (SEM), and Surface area measurements (BET). The optimum conditions of sorbent dosage, pH, initial concentration, and contact time factors were investigated for pristine limestone and calcined limestone absorbents. The results indicate that the optimum initial concentrations of (Ci) were 1200, 500, and 300 ppm for Pb, Cu, and Cd, respectively, using calcined limestone adsorbent, while using the pristine limestone adsorbent, the corresponding optimum initial concentrations were 700, 110, and 50 ppm. In the ternary system sorption, the results indicated that the selectivity sequence of the studied metals by limestone can be expressed as Pb2+ > Cd2+ > Cu2+, while calcined limestone exhibits a higher selectivity for Pb2+ compared to Cu2+ and Cd2+. Hence, various adsorption isotherm and kinetic models were examined to explore different patterns and behaviors of adsorption. So, the results indicate that calcined limestone has great potential for eliminating cationic heavy metal species from industrial water solutions.

Synthesis and structural insights of bis(2-methoxy-6-{[(2-methylpropyl)imino]methyl}phenolato) nickel (II) complex through DFT and docking investigations

Nickel complexes are a potential candidate for antibacterial and antifungal activity. A new Ni (II) complex, bis(2-methoxy-6-{[(2-methylpropyl)imino]methyl}phenolato)nickel (II) (2), was synthesised by reacting, bis(3-methoxy-salicylaldehyde)nickel (II) (1) with isobutylamine. It was characterised by single crystal X-ray diffraction (ScXRD), UV-Vis, NMR, IR, mass spectrometry, and thermogravimetry (TG) to study its structure and physico-chemical properties. The ScXRD showed a square planar geometry, and monoclinic crystal system with a space group P21/n. The TG analysis revealed its thermal durability pre and post-melting up to 225 oC with a weight loss of only 2%. The optimized molecular structure, energy gap between HOMO and LUMO, and intermolecular interactions were studied by computational methods. The microbial activity evaluation showed significant anti-bacterial activity against E. coli and S. aureus when the concentration exceeded 40 µg/mL, and a prominent anti-fungal activity over C. albicans and C. tropicalis above 30 µg/mL. The values of minimum inhibitory concentration (MIC) for bacteria (MIB) and fungi (MIF) implied its potential to inhibit the growth of microbes. Docking studies revealed that the molecule binds well with proteins such as PDB: 2W9H for Dihydrofolate Reductase of S.aureus as shown by its binding energy of -8.62 kcal.mol− 1.

In Vitro, In Vivo, Ex Vivo Characterisation of Dihydroimidazotriazinones and Their Thermal Decomposition Course Studied by Coupled and Simultaneous Thermal Analysis Methods.

The biological and thermal properties of a class of synthetic dihydroimidazotriazinones were disclosed in this article for the first time. Molecules 1-6-as potential innovative antimetabolites mimicking bicyclic aza-analogues of isocytosine-were evaluated for their in vitro anticancer activity. Moreover, in vivo, in vitro, and ex vivo toxicity profiles of all the compounds were established in zebrafish, non-tumour cell, and erythrocyte models, respectively. Their antihaemolytic activity was also evaluated. Additionally, the thermal decomposition mechanism, path, and key thermal properties of heterocycles 1-6 were analysed. It was found that all the studied compounds revealed significant antiproliferative activities against tumour cells of the lung, cervix, ovary, and breast, as well as acute promyelocytic leukaemia cells, superior or comparable to that of an anticancer agent gemcitabine. Most of them were less toxic to non-tumour cells than this standard drug, and none had a haemolytic effect on red blood cells. All the tested heterocycles proved to be safer for zebrafish than a standard drug pemetrexed. Some exhibited the ability to inhibit oxidative haemolysis, suggesting their protective action on erythrocytes. The differential scanning calorimetry (DSC) analyses confirmed that all molecules melted within one narrow temperature range, proving their purity. The melting points depended solely on the type of substituent and increased as follows: 4 (R = 3-ClPh) < 2 (R = 4-CH3Ph) = 3 (R = 4-OCH3Ph) < 5 (R = 4-ClPh) = 1 (R = Ph) < 6 (R = 3,4-Cl2Ph). The thermogravimetry/differential thermogravimetry (TG/DTG) studies confirmed high thermal stability of all the investigated heterocycles in inert (>230 °C) and oxidising (>260 °C) atmospheres, which depended directly on the R. The pyrolysis process included one main decomposition stage and was connected with the emission of NH3, HCN, CH3CN, HNCO, alkane, alkene, aromatic fragments, CO2 (for all the compounds), and HCl (for the molecule with 3,4-Cl2Ph), which was confirmed by FTIR and QMS analyses. In turn, the oxidative decomposition process of the tested polyazaheterocycles took place in two main stages connected with the formation of the same volatiles as those observed in an inert atmosphere and additionally with the release of N2, NO, CO, and H2O. These results proved that the pyrolysis and oxidative decomposition run through the radical mechanism connected with the additional reactions between radicals and oxygen in synthetic air. The favourable biological and thermal properties of this class of dihydroimidazotriazinones imply their usefulness as potential pharmaceutics.

Influence of biochar on drying shrinkage and microstructure of CO2-cured CaSiO3 cements

This article examines the effect of biochar on the properties of carbonated wollastonite pastes. Phase composition and microstructure were evaluated using thermogravimetric analysis, Fourier transform infrared spectroscopy, x-ray diffraction, scanning electron microscopy, nitrogen adsorption, and x-ray microcomputed tomography. The results showed a higher compressive strength in the carbonated pastes with biochar compared to the control paste. This is attributed to the internal curing effect of the biochar, which results in pore structure refinement. Biochar was shown to effectively reduce drying shrinkage in the carbonated pastes, which in turn resulted in decreased drying shrinkage induced cracking. The CaCO3 content was shown to be dependent on the concentration of biochar as the paste with 2% biochar showed a lower and the paste with 4% biochar showed a higher CaCO3 compared to the control paste. Calcite was shown to comprise the primary polymorph of CaCO3 in the carbonated pastes with and without biochar.

Comparison of Aging Performances and Mechanisms: Super-Durable Fire-Resistant "Xuan Paper" Versus Chinese Traditional Xuan Paper.

Paper is a thin nonwoven material made from cellulose fibers as the main raw material together with some additives. Paper is highly flammable, leading to the destruction of countless precious ancient books, documents, and art works in fire disasters. In recent years, researchers have made a lot of efforts in order to obtain more durable and fire-retardant paper. Owing to the successful synthesis of ultralong hydroxyapatite (HAP) nanowires as a new kind of inorganic nanofiber material, it becomes possible to develop a new kind of super-durable and fire-resistant paper. Recently, the authors' research group prepared a new kind of fire-resistant "Xuan paper" consisting of ultralong HAP nanowires. In this article, the super-durable fire-resistant "Xuan paper" based on ultralong HAP nanowires and the traditional Xuan paper based on cellulose fibers were evaluated by the accelerated aging method for 1200 days at 105 °C in air, which is the equivalent of 10,000 years of natural aging in the ambient environment. The aging mechanism of the traditional Xuan paper was further investigated by studying the fiber length/width and their distributions, morphology, infrared spectroscopy, thermogravimetric analysis, H-nuclear magnetic resonance spectra, and C-nuclear magnetic resonance spectra of cellulose fibers before and after the accelerated aging. The durability, properties, and mechanism of the fire-resistant "Xuan paper" based on ultralong HAP nanowires during the accelerated aging were studied. The experiments reveal the reasons for the deteriorated properties and reduced durability by aging of the traditional Xuan paper based on cellulose fibers, and the mechanism for the super-durability and excellent performances of the fire-resistant "Xuan paper" based on ultralong HAP nanowires during the accelerated aging process.

Catalytic Effects of Different Metal Salts on Cotton Waste Textiles by Pyrolysis: Pyrolysis Behavior and Properties of Activated Carbon

This study was conducted to explore the catalytic effects of different metal salts on the pyrolysis behavior of cotton waste textiles (CWTs) and the properties of their activated carbons (ACs). The decomposition characteristics of CWTs with Zn, Fe, and Cu salts were studied by thermogravimetric analysis (TGA) to analyze the catalytic effects. The physical and chemical characteristic differences of the ACs were detected with SEM-EDS, BET, FTIR, and XPS. The results show that metal salts reduced the decomposition temperature of the CWTs and improved the pore structures and specific surface areas of the activated carbons (ACs). The ACs produced abundant acidic surface functional groups on their surfaces, which facilitated the selective adsorption of pollutants. This study indicates that cotton waste textile biochar treated with metal salts may be a promising adsorbent for the removal of heavy metals and organic pollutants.

Glass/Polyester Laminates Modified with L-Arginine Phosphate-Effects on the Flammability and Smoke Emission.

Flammability and smoke generation of glass-fiber-reinforced polyester laminates (GFRPs) modified with L-arginine phosphate (ArgPA) have been investigated. The composition, structure, and thermal degradation processes of ArgPA were assessed by the elemental, FTIR, and thermogravimetric analyses. Flammability and smoke emission of GFRPs varying by different amounts (5-15 wt.%) of bio-based flame retardant (FR) prepared via hand lay-up method were assessed in terms of the limiting oxygen index (LOI) and smoke density tests. It was observed that the addition of ArgPA results in the formation of a charred layer with visible bubbles. The LOI of GFRP with 15 wt.% of ArgPA increased from 20.73 V/V % (non-modified GFRP) to 24.55 V/V %, and the material classification was improved from combustible to self-extinguishing. FRs usually increase the specific optical density of smoke, which was also observed for ArgPA-modified GFRPs. However, the specific optical density of smoke at the 4th minute of measurement (Ds(4)) obtained for ArgPA-modified GFRPs was lower than for GFRPs modified with commercially used APP. TG/FTIR studies of resin modified with ArgPA revealed the presence of phosphorus compounds and non-combustible gases in the decomposition products. Results demonstrate the potential of ArgPA as an effective, bio-based FR for the enhancement of GFRP fire safety.

The Influence of Leather Type on Thermal and Smoke-Generating Properties.

The main purpose of this article was to determine the smoke-generating and thermal properties of selected types of natural leather. Differences in the amount of smoke generated from the type of finish used in the technological processing of leather were observed. Research has shown that the burnt nubuck (367) sample with exposure at the heat flux intensity of 25 kW/m2 without the presence of a pilot burner flame achieved the highest value of the specific optical density Ds,max. Comparable values, 312 and 297, were recorded for grain bovine leather and velour bovine leather, respectively; on the other hand, the lowest value of the tested parameter amounting to 220 was recorded for lacquered bovine leather. Tests executed with the use of thermogravimetric analysis show that except for nubuck leather, the start of thermal decomposition for all types of samples appears to be fairly similar and was found to be within the range of 275-282 °C. The highest value of thermal decomposition onset, i.e., 302 °C, was recorded for nubuck leather. The highest percentile of residues from thermal decomposition, i.e., 9%, was obtained for grain bovine leather. This implies that the least gaseous phase during its thermal decomposition in test conditions was generated by this type of leather. The highest average Ds,max value was obtained for nubuck (367), and decreased as follows: grain bovine leather (312) > velour bovine leather (297) > lacquered bovine leather (220).

Selective separation of tanshinone homologs by biocomposite membranes based on poly(ionic liquids) and natural fibers.

Membranes have been used as versatile tools for the separation of various natural products; however, the selective separation of structural analogs of natural products using membranes remains challenging. In this study, biocomposite membranes based on poly(ionic liquids) and different natural fibers (jute, cotton, or wool) were successfully prepared. Natural fibers can regulate the microstructure and improve the mechanical properties of membranes. Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, atomic force microscopy, Brunauer-Emmett-Teller analysis, and thermo gravimetric analysis were used to characterize the membranes. The membranes were used to separate tanshinone homologs (tanshinone I, tanshinone IIA, cryptotanshinone, and dihydrotanshinone I), allowing cryptotanshinone to penetrate the membrane while rejecting tanshinone I. A maximal selectivity of 44.57% was obtained for the tanshinone homologs using a one-step separation protocol. These poly(ionic liquids)/natural fiber membranes possess high water flux, good self-cleaning, and good antibacterial properties. The membranes were effective in separating tanshinone homologs and have the potential to separate other natural homologs.

Co-Pyrolysis of Plastic Waste and Lignin: A Pathway for Enhanced Hydrocarbon Recovery

Various plastics and biomass wastes, such as polypropylene (PP), low- or high-density polyethylene (LDPE/HDPE), and lignin, have become some of the most concerning wastes nowadays. In this context, this study aimed to investigate the possibility of applying thermochemical processes for the valorization of these materials. The experiments were carried out using a thermogravimetric analyzer on individual plastic and lignin samples and their mixtures at different mass ratios of 1:1, 1:2, 1:3, and 1:4. The gaseous products evolved during the pyrolysis process were analyzed by combined thermogravimetric and Fourier-transform infrared spectroscopy (TG-FTIR) and chromatography-mass spectrometry (Py-GC/MS) to analyze the functional groups and chemical composition of the obtained pyrolysis products. The results showed that the main functional groups of lignin monitored by TG-FTIR were aromatic and aliphatic hydrocarbons, while all plastics showed the same results for hydrocarbons. The investigation confirmed that mixing these types of plastics with lignin at different mass ratios led to increased recovery of higher-value-added products. Py-GC/MS analysis showed that the greatest results of compound recovery were achieved with lignin and LDPE/HDPE mixtures at 600 °C. At this temperature and with a mass ratio of 1:3, the plastic’s radicals enhanced the depolymerization of lignin, encouraging its wider decomposition to hydrocarbons that can be applied for the production of value-added chemicals and bio-based energy.

Effect of Crystallinity on the Printability of Poly(ethylene Terephthalate)/Poly(butylene Terephthalate) Blends.

This study explores the impact of blending polyethylene terephthalate (PET) with polybutylene terephthalate (PBT) on the thermal, structural, and mechanical properties of 3D-printed materials. Comprehensive analyses, including Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and mechanical testing, were conducted to assess the influence of blend composition. FT-IR confirmed that PET and PBT blend physically without transesterification, while TGA showed enhanced thermal stability with increasing PET content. XRD revealed that PET and PBT crystallize separately, with the crystallinity decreasing sharply for blends with more than 50% PET. The DSC results indicated that PET effectively slows down the crystallization kinetics of PBT, promoting cold crystallization. Mechanical tests demonstrated that the elastic modulus remains relatively unchanged, but the strain at break decreases with a higher PET content, indicating increased stiffness and reduced ductility. Overall, incorporating PET into PBT improves 3D-printability and dimensional stability, reducing warpage and enhancing print precision, making these blends advantageous for 3D-printing applications.

Carboxylated Graphene: An Innovative Approach to Enhanced IgA-SARS-CoV-2 Electrochemical Biosensing.

Biosensors harness biological materials as receptors linked to transducers, enabling the capture and transformation of primary biorecognition signals into measurable outputs. This study presents a novel carboxylation method for synthesizing carboxylated graphene (CG) under acidic conditions, enhancing biosensing capabilities. The characterization of the CG was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Raman spectroscopy, thermogravimetric analysis (TGA), and X-ray diffraction (XRD). We modified screen-printed carbon electrodes (SPCEs) with CG to immobilize the SARS-CoV-2 N-protein, facilitating targeted detection of IgA antibodies (IgA-SARS-CoV-2). The analytical performance was assessed via electrochemical techniques such as cyclic voltammetry and electrochemical impedance spectroscopy, confirming CG synthesis effectiveness and biosensor functionality. The developed biosensor efficiently detects IgA-SARS-CoV-2 across a dilution range of 1:1000 to 1:200 v/v in a phosphate-buffered saline (PBS) solution, with a limit of detection calculated at 1:1601 v/v. This device shows considerable potential because of its fast response time, miniaturized design facilitated by SPCEs, reduced sample volume requirements, high sensitivity and specificity, low detection limits, and signal enhancement achieved through nanomaterial integration.

Sustainable synthesis of silver nanoparticles from Conocarpus seeds for removal of methylene blue

This study introduces a sustainable biological approach for synthesizing silver nanoparticles (AgNPs) using Conocarpus seeds, aimed at improving the adsorption and photocatalytic degradation of methylene blue (MB) in wastewater treatment. The photocatalytic efficiency of AgNPs, synthesized under varying concentrations of silver nitrate (AgNO3) and pH levels, was evaluated, together with the effectiveness of a photocatalytic reactor. The synthesized samples were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier-transform infrared (FT–IR) spectroscopy, and atomic force microscopy (AFM). Results showed that MB degradation occurred quickly within the first 50 min, achieving a 99.60% removal efficiency via adsorption and photocatalytic degradation under optimal conditions (pH = 3, 1 g sample) after 1 h. The maximum adsorption capacity reached 49.80 mg·g−1. Furthermore, the AgNPs demonstrated a significant degradation rate of 99.76% within 2 h under UV light, highlighting the synergistic effects of AgNPs in enhancing both adsorption and photocatalysis. This study not only accentuates the potential of Conocarpus seeds as an eco-friendly precursor for AgNP synthesis but also highlights the applicability of AgNPs in wastewater treatment.

A carbon fiber modified with tin oxide/graphitic carbon nitride as an electrochemical indirect competitive immuno-sensor for ultrasensitive aflatoxin M1 detection.

The importance of developing multifunctional nanomaterials for sensing technologies is increasing with the arrival of nanotechnology. In this study, we describe the introduction of novel nanoprobe electro-active material into the architecture of an electrochemical immuno-sensor. Based on the electrochemical immuno-sensor, functionalized tin oxide/graphitic carbon nitride nanocomposite (fSnO2/g-C3N4) was synthesized and then analyte specific anti-aflatoxin M1 monoclonal antibody (AFM1-ab) combined to form an electro-active nanoprobe (fSnO2/g-C3N4/AFM1-ab). First, aflatoxin M1 (AFM1) conjugated bovine serum albumin (BSA-AFM1) was electro-oxidized on the surface of carbon fiber (CF) followed by the consequent addition of nanoprobe. The formation of nanocomposite was substantiated through various characterization techniques, Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Dynamic light scattering (DLS). Immuno-sensor fabrication was characterized via Field emission scanning electron microscopy (FE-SEM), optical microscope images, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). This immuno-sensor demonstrated good reproducibility, selectivity, specificity and sensitivity for AFM1 (LOD of 0.03ng mL-1). Following spiking, this immuno-sensor produced good recovery values in the range of 94-96% against real sample, such as milk. The development of sophisticated sensing methods for a range of analytes can greatly benefit from the widespread application of this innovative immuno-sensing approach.

Magnetite Nanoparticles Encapsulated with PBS-PEG for AMF Hyperthermia.

Novel studies on typical synthesized magnetite nanoparticles were encapsulated into a poly (butylene succinate)/poly (ethylene glycol) copolymer (PBS-PEG). PBS was chosen because of its biocompatibility characteristics necessary for biomedical applications. PEG, as part of the macromolecular structure, increases the hybrid system's solubility in an aqueous environment, increasing the circulation time of the material in the bloodstream. The immune system has difficulty recognizing particles with good solubility in an aqueous medium and with a diameter until 200 nm, preventing the body from eliminating the nanoparticles before the magnetic hyperthermia is performed. All the prepared materials were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic light scattering (DLS), and zeta potential. The detailed investigated result executes the formulation developed in this work, showing it has potential and that further studies and analyses can be carried out so that the formulation can be improved, thus obtaining even better results.

Early Strength Enhancement Mechanism of CaO-Modified Electrolytic Manganese Residue-Based Supersulfate Cement.

Electrolytic manganese residue (EMR) is a solid waste generated during the production of electrolytic manganese metal through wet metallurgy, accumulating in large quantities and causing significant environment pollution. Due to its high sulfate content, EMR can be utilized to prepare supersulfate cement when combined with Ground Granulated Blast furnace Slag (GGBS). In this process, GGBS serves as the primary raw material, EMR acts as the sulfate activator, and CaO powder, along with trace amounts of cement, functions as the alkali activator. This results in the preparation of CaO-modified electrolytic manganese residue-based supersulfate cement (Abbreviated as "SSC"), facilitating the harmless and resourceful utilization of EMR. This study aims to determine the optimal dosage of CaO as the alkali activator for GGBS in SSC. A comprehensive analysis was conducted on four groups, including a control group. The mass ratio of EMR, GGBS, and cement in SSC was fixed as 35:60:5, and the optimum mixing ratio of lime powder as an external admixture was investigated through mechanical tests and microscopic experiments. The hydration products and mechanism of the cementitious materials were analyzed using X-ray diffraction (XRD), pH measurements, thermogravimetric and differential thermogravimetric analysis (TG-DTG), mercury intrusion porosimetry (MIP), and scanning electron microscopy (SEM). The results indicated that, under the combined influence of trace cement and raw lime powder, EMR effectively activated GGBS. The primary hydration products of the SSC are AFt and hydrated calcium silicate (C-S-H), which contributed to the mechanical strength of the SSC. At a hydration age of 3 days, the optimal CaO blending ratio was found to be 8% by mass of dried EMR. With this ratio, the compressive strength of SSC reached 18.2 MPa, the pore size of hardened slurry was refined, the structure became dense, and hydration products increased. It could be concluded that CaO enhances the early strength of SSC when used as an alkali activator.

Crosslinking-induced compatibility and toughness enhancement in poly(lactic acid)/poly(3-hydroxybutyrate-co-4-hydroxybutyrate) blends with epoxidized soybean oil.

Polylactide (PLA) is inherently brittle and lacks ductility, which greatly restricts its range of applications. In order to address these issues, we blended PLA with biodegradable poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)), and introduced epoxidized soybean oil (ESBO) as a reactive modifier to enhance the properties of the PLA/P(3HB-co-4HB) blends. Furthermore, we used theoretical calculations, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Soxhlet extraction, differential scanning calorimetry (DSC), polarising optical microscopy (POM), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and mechanical testing to investigate the compatibility, crystallization behavior, microstructure, thermal and mechanical properties of the PLA/P(3HB-co-4HB)/ESBO blends. The mechanisms underlying these properties were analyzed in detail. ESBO was found to form cross-linking grafts between PLA and P(3HB-co-4HB), strengthening interfacial bonding and thereby enhancing compatibility. The in situ formation of graft copolymers resulted in finer, more uniform dispersion of P(3HB-co-4HB) and ESBO droplets within the PLA matrix, further improving interfacial adhesion and overall material compatibility. With the addition of 5 wt% ESBO, the tensile strain at break of PLA/P(3HB-co-4HB)/ESBO films increased from 114.6 % to 453.3 %, while the notched impact strength improved from 3.75 kJ∙m-2 to 8.75 kJ∙m-2, compared to PLA/P(3HB-co-4HB) films. However, excessive ESBO slightly decreases the mechanical performance of the material.

Effect of pentaerythritol derived phosphorous based bicyclic polymer on the flammability

1-oxyphospha-4-hydroxymethyl-2,6,7-trioxabicyclo [2.2.2] octane (PEPA) was synthesized successfully in producing a PEPA-based monomer having an acrylate group and its polymers. Nuclear magnetic resonance (NMR), 1H, and 31P spectra were used to establish their structural integrity. Thermogravimetric analysis (TGA), the limited oxygen index (LOI), and the UL-94 test were used to examine the thermal characteristics and flame retardant behavior of the systems with 15 wt% of flame retardants (PhosPTPU15, Phosphorous functionalized polymer thermoplastic polyurethane). Thermoplastic polyurethane (TPU), the results reveal that LOI increases from 19% to 27.8% with the incorporation of 15 wt% PhosPTPU15. SEM-EDX was used to evaluate the morphology of the TPU and its blend, which exhibits that with the incorporation of PhosPTPU15 the blend showed compact morphology and supported the condensed phase mechanism of the blends.