Maximum Degradation Temperature Research Articles

Investigating the synergistic effects of carbon and glass fibers on the mechanical and thermal properties of phenol‐containing phthalonitrile composites

AbstractThe progressive development of lightweight composites exhibiting desirable thermo‐mechanical properties is an area of growing interest, particularly with the phthalonitrile (PN) based composites, which have shown great potential. However, our understanding of the mechanical and thermal properties of the phenol‐containing phthalonitrile (PN75) resin composites often reveals limitations that make them less suitable for specific structural applications. In this work, we focused on enhancing the mechanical and thermal properties of the PN75 resin through the incorporation of the 4‐aminophthalonitrile (4‐APN), resulting in improved the curing behaviors and increased thermal stability. Our investigation of the short carbon fiber (SCF) and short glass fiber (SGF) reinforced PN75 resin composites revealed that the hybrid SCF/SGF‐based composites at 15 wt% SCF and 15 wt% SGF content exhibited an excellent tensile and the flexural strength. Additionally, the thermogravimetric analysis demonstrated maximum onset degradation and decomposition temperatures at this ratio compared with the neat resin, also we evaluated the interfacial adhesion properties of the SCF/SGF and the PN75 resin composites. These findings contribute to the advancement of polymer composite materials and expand their potential applications across various industries.

Study of alkali and acetylation treatments on sisal fibers compatibility with low-amine/epoxy stoichiometric ratio

Sisal fibers are one of the most commercially utilized as reinforcing agents in composite materials. However, sisal fibers are very hydrophilic because they contain many hydroxyl groups, so their interfacial bonding is low when mixed with a non-polar polymer matrix. One method to improve the fiber-matrix interfacial bond is to modify the sisal fiber surface with chemical treatment. This study evaluated the influence of various chemical treatments on the tensile properties and interfacial adhesion of sisal fibers reinforced with low-amine/epoxy stoichiometric ratio resin. The sisal fibers were subjected to a series of treatments, including 2 wt% alkali for 4 h, acetylation for 1 h, and a combined alkali and acetylation treatment. The FT-IR analysis confirmed the success of the acetylation process by the presence of the carbonyl signal (1728 cm−1). The XRD analysis indicated that the crystallinity index of the sisal fiber (65 %) was increased after alkali (75 %) and acetylation (66 %) treatments. The alkali-treated sisal fibers showed the highest tensile strength (728 MPa) but the lowest interfacial shear strength (17.7 MPa). The acetylated-treated sisal fibers exhibited the highest tensile modulus (44.5 GPa) and interfacial shear strength (25 MPa). However, the combination of alkali and acetylation treatments reduced the tensile strength of the fiber from 659 to 619 MPa. The TGA results revealed that the maximum degradation temperature of sisal fibers (344 °C) was increased after alkali (349 °C), acetylation (348 °C), and a combination of alkali and acetylation (350 °C) treatments. The results suggest that acetylation treatment is highly beneficial for advanced composite applications.

Characterization of Novel Cellulosic Salvadora Persica Fiber for Potentiality in Polymer Matrix Composites

ABSTRACT Natural fiber is expected to make polymer composites light and environmentally friendly. In this paper Salvadora persica natural fiber is characterized in view of its use in composite materials for the first time. Average diameter of the fiber was 250 µm and density was 1.3 g/cm3. The surface of the fiber was irregular with impurities and surface features such as shallow tubs, cell walls and lignin were revealed by Scanning Electron Microscopy (SEM). X-ray diffraction (XRD) analysis reveals Crystallinity Index (C.I) of 58% and Crystallite Size of 3.58 nm. The chemical bonds pertaining to different constituents of the natural fiber such as cellulose, hemicellulose and lignin were identified by Fourier Transform Infrared (FTIR) spectroscopic analysis. In the thermal degradation of the fiber during the Thermogravimetric analysis (TGA), three stages were identified. The maximum thermal degradation temperature (Tfinal) was determined to be 357°C. Tensile strength, Young’s modulus and percentage elongation of the fiber were 430 ± 100 MPa, 16 ± 3.9 GPa and 4.2 ± 0.91% respectively.

Sustainable lignocellulosic mediterranean biocomposites: Thermogravimetric analysis, mechanical performance, morphological and comparative study

Utilizing accessible agricultural waste to create sustainable materials is a potentially beneficial attempt toward developing better bio-products and a more sustainable socioeconomic environment. Accordingly, this work aims to investigate the mechanical performance enhancement and/or deteriorations as well as morphological and thermal characteristics of certain Mediterranean lignocellulosic fiber composites considering various reinforcement conditions. Several composites of polypropylene pomegranate peel powder (PG) and short corn leaves (CL) were designed and fabricated with various reinforcement conditions to demonstrate their potential characteristics. Moreover, the experimental results of this work were compared with commonly used fiber/PP composites worldwide to demonstrate their appropriateness for producing bio-based composites suitable for various applications. The investigations included determining the tensile strength, tensile modulus, elongations at break properties under various reinforcement conditions, as well as revealing the thermal properties of the fibers to expose their suitability for such bio-based composites to improve utilizing such available waste of fibers into useful materials for various mechanical components. Thermal gravimetric analysis (TGA) and derivative thermal gravimetric analysis (DTG) were also carried out to examine thermal stability and to distinguish the maximum degradation temperature (Tmax) of the cellulosic fiber compositions. The outcomes revealed that both types of fibers, pomegranate peel powder and short corn leaves, had positive impacts on the tensile strength and modulus of PP regardless of the weight percentage. The 40 wt% of corn leaves displayed the best improvement in the strength (+29 %) and modulus (+17 %). The 40 wt%, CL-PP reached tensile modulus of 1589.5 MPa, whereas the best modulus for the PG-PP was 1399.4 MPa at 30 wt%. When comparing the tensile strength and modulus of PG/PP and CL/PP composites with those reported in the literature, these composites demonstrated superior tensile properties relative to thirteen other types documented. Regarding the thermal analysis, PG and CL fibers could withstand the processing temperature without degradation, which enables them to be feasibly utilized in bio-based composites to enhance the development of green bio-products. When it comes to the morphological analysis, it was observed that there was a good adhesion between PP and CL, which interprets the enhancement tensile properties.

Combined effects of organic solvent and ultrasonic pretreatments on cellulose fiber extraction from hemp

Extracting pure cellulose fibers from hemp bast for potential textile industry applications requires the removal of non-cellulosic gummy materials. However, traditional degumming methods are largely limited because of the long procedure time, high energy consumption, heavy environmental pollution and insufficient efficiency. Organic solvents have been proved to be an innovative method for lignocellulose extraction. Herein, ethylene glycol solvent combined ultrasonic pretreatment was explored to degum hemp fibers without any further treatment. The purified hemp fibers were systematically characterized using analytical test techniques. Results revealed that the combined degumming could effectively remove non-cellulosic components without damaging the cellulose, and reducing the reaction temperature by 10 ℃ for reaction process. Comparing to the traditional method, the fibers by ultrasonic pretreatment-ethylene glycol process had superior average yield of 68.32 %, higher thermal stability (maximum degradation temperature reached 395 ℃), higher breaking tenacity of 6.13 cN/dtex, higher crystallinity of 78 % and the cellulose content of over 91 %. Moreover, the degumming time and chemical usage were reduced to 40 % and 51.8 %, respectively. Besides, the changes of fibers chemical structure were further investigated and verified by FTIR, EDS, and 13C NMR analysis. Featured with less chemical and energy consumption, eco-friendly and short time-consuming, this treatment has a broad application scope for hemp cellulose fiber extraction.

Characterisation of Bambara groundnut (Vigna subterranea (L.) Verdc.) shell waste as a potential biomass for different bio-based products.

Efforts are ongoing to utilise agricultural waste to achieve a full resource use approach. Bambara groundnut is an important crop widely grown in the sub-Saharan Africa with potential future importance because of its resilience to thrive under heightened weather uncertainty and widespread droughts that have challenged food security. After harvesting, the edible nuts are separated from the shells which are discarded as waste. Therefore, this research is aimed at characterising the chemical composition and the structural properties of Bambara groundnut shells (BGS) in view of their potential application as a biomass for different bio-products. The chemical composition of BGS was found to be 42.4% cellulose, 27.8% hemicellulose, 13% lignin and 16.8% extractives. Proximate analysis showed a high amount of volatile matter (69.1%) and low moisture (4.4%). XRD analysis confirmed crystallinity of cellulose I polymer and FTIR analysis observed functional groups of lignocellulosic compounds. Thermal stability, maximum degradation temperature and activation energy were found to be 178.5°C, 305.7°C and 49.4kJ/mol, respectively. Compared to other nutshells, BGS were found to have a relatively high amount of cellulose and crystallinity that may result in biocomposites with improved mechanical properties.

Development and characterization of UV‐curable PCL/AESO/CNT nanocomposites for biomedical engineering

AbstractThis study investigates the development and characterization of UV‐curable Poly(ε‐caprolactone) (PCL), Acrylated Epoxidized Soybean Oil (AESO), and Carbon Nanotubes (CNT) nanocomposites for biomedical engineering applications. The PCL/AESO blends were prepared in various ratios, and CNTs were incorporated at concentrations of 0.5, 1.0, and 1.5 wt% to enhance mechanical properties. The UV‐curable formulations aimed to leverage rapid curing times, precise control over material properties, and the ability to fabricate complex structures. Results indicated that the incorporation of CNTs improved the tensile strength, modulus, and toughness of the composites. The PCL/AESO/CNT nanocomposites exhibited a tensile strength increase of 25%, a modulus improvement of 30%, and a toughness enhancement of 20% compared to pure PCL. Thermal analysis showed an increase in crystallization temperature and thermal stability, with a crystallinity degree of 63.31% and a maximum degradation temperature of 407°C for the B/C 50/50/1.5 sample. Biocompatibility assessments using L929 fibroblast cells revealed that the composites supported cell viability and proliferation over 7 days with negligible cytotoxicity. Cell attachment studies indicated favorable morphology and adherence, suggesting a conducive environment for cell growth and differentiation. Hydrolytic biodegradation studies demonstrated adjustable degradation rates, making these composites suitable for various biomedical applications requiring controlled biodegradation.

Addition of Coffee Waste-Derived Plasticizer Improves Processability and Barrier Properties of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-Natural Rubber Bioplastic.

This study aimed to develop a value-added bio-based polymer product for food packaging. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a promising bioplastic with limitations in processability and brittleness, which our group previously addressed by incorporating high-molecular-weight natural rubber (NR) compatibilized with peroxide and coagent. Yet, processability in an industrial setting proved difficult. Coffee oil epoxide (COE), a waste-derived plasticizer, was incorporated into the PHBV/NR/peroxide/coagent matrix via extrusion, and properties of resulting sheets were evaluated. COE incorporation significantly decreased the oxygen and water permeability of the PHBV/NR sheets. Maximum degradation temperature Tpeak (°C) increased by ~4.6 °C, and degree of crystallinity decreased by ~15.5% relative to pristine PHBV, indicating good thermal stability. Melting (Tm) and glass transition temperatures (Tg) of the PHBV/NR blend remained unchanged with COE incorporation. X-ray diffraction (XRD) revealed ~10.36% decrease in crystal size for the plasticized blend. Energy-dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM) confirmed good dispersion with no phase separation. The water uptake capacity of the plasticized blend was reduced by 61.02%, while surface contact angle measurements showed improved water resistance. The plasticized PHBV sheet shows promise for environmentally friendly packaging films due to its high thermal stability, effective barrier properties, and industrial scalability.

Greening the composite industry: Evaluating Lantana camara Verbenaceae fiber as a promising substitute for lightweight polymer matrix composites

Presently, researchers are engaged in investigations with the aim of developing novel products that exhibit biodegradability and subsequent environmental friendliness. As products, biofiber-based composites are gaining popularity in various industries. Consequently, this investigation successfully identified a unique cellulosic stem fiber from Lantana camara L. (Verbenaceae) plant. As the fiber was unique, sustainable, and abundantly available throughout all seasons, it was selected for the comprehensive characterization investigation to find its potential use as a lightweight bio-based composite material substitute for synthetic fibers. Physiochemical examination revealed that the Lantana camara Verbenaceae fiber had a greater cellulose concentration (61.23±8.42 %) and density (1167±60 kg/m3), measured to be very less compared to synthetic fiber, making a perfect choice for producing lightweight composites with higher strength. The presence of cellulose Iβ and the ordered character of the crystallites were verified by Fourier transform infrared spectroscopy and X-ray diffraction method. Thermogravimetric study showed the maximum degradation temperature of 323 °C, a thermal stability of 242 °C, and a kinetic activation energy of 66.11 kJ/mol. The maximum tensile strength, strain-to-failure percent, and Young’s modulus were observed for 50-mm-length fibers. Detailed analysis of the longitudinal section of the fiber from atomic force microscopy and scanning electron microscopy study revealed that the fiber had a rough surface, which improves the bonding behavior when reinforced. The aforementioned properties showed that L. camara L. fibers are an excellent, greener alternative reinforcement for composite materials, allowing for the cleaner, more sustainable components.

FACILE SYNTHESIS OF CARBOXYMETHYL CELLULOSE (CMC) FROM AGRICULTURAL RESIDUES

Cellulose derivative products, such as carboxymethyl cellulose (CMC), which are used in the food, cosmetics, and pharmaceutical industries, but still rely on cotton-derived cellulose, can be made from oil palm fruit empty bunches (OPEFB) and rice straw. This study examined how sodium monochloroacetic acid (NaMCA) concentration (3, 6, and 9 g) affected the simple synthesis and characteristics of CMC from OPEFB and rice straw cellulose. OPEFB-derived CMC produced with NaMCA (9 g) had the lowest of brightness, while rice straw CMC was brighter. NaMCA modifications altered the onset temperature (Tonset), but not maximum degradation temperature (Tmax), according to thermal analysis. The onset temperatures of OPEFB and rice straw CMC were 40–62 °C and 67–183 °C, respectively. Commercial CMC has an onset temperature of about 27 °C. The EDX analysis showed that rice straw CMC had a higher degree of substitution (DS) of 0.34–1.37 than OPEFB CMC, which had 0.30-0.70. Oil palm empty fruit bunch (OPEFB) cellulose and rice straw cellulose offer a viable carboxymethyl cellulose (CMC) alternative. This process turns agricultural waste into valuable products and enables for their usage in numerous applications.

The rigid-flexible balanced molecular crosslinking network transition interface: An effective strategy for improving the performance of bamboo fibers/poly(butadiene succinate-co-butadiene adipate) biocomposites

The poor interfacial compatibility of natural fiber-reinforced polymer composites has become a major challenge in the development of industry-standard high-performance composites. To solve this problem, this study constructs a novel rigid-flexible balanced molecular crosslinked network transition interface in composites. The interface improves the interfacial compatibility of the composites by balancing the stiffness and strength of the fibers and the matrix， effectively improving the properties of the composites. The flexural strength and flexural modulus of the composites were enhanced by 38 % and 44 %, respectively. Water absorption decreased by 30 %. The initial and maximum thermal degradation temperatures increased by 20 °C and 16 °C, respectively. The maximum storage modulus increased by 316 %. Furthermore, the impact toughness was elevated by 41 %, attributed to the crosslinked network's efficacy in absorbing and dissipating externally applied energy. This innovative approach introduces a new theory of interfacial reinforcement compatibility, advancing the development of high-performance and sustainable biocomposites.

An antibacterial film using κ-carrageenan loaded with benzyl isothiocyanate nanoemulsion: Characterization and application in beef preservation

Benzyl isothiocyanate (BITC) is a naturally active bacteriostatic substance and κ-carrageenan (KC) is a good film-forming substrate. In the present study, a nanoemulsion incorporating BITC was fabricated with a particle size of 224.1 nm and an encapsulation efficiency of 69.2 %. Subsequently, the acquired BITC nanoemulsion (BITC-NE) was incorporated into the KC-based film, and the light transmittance of the prepared composite films was lower than that of the pure KC film. Fourier transform infrared spectroscopy and scanning electron microscopy revealed that BITC-NE was compatible with the KC matrix. BITC-NE incorporation enhanced the tensile strength of the KC-based films by 33.7 %, decreased the elongation at break by 33.8 %, decreased the water vapor permeability by 60.1 %, increased the maximum thermal degradation temperature by 48.8 %, and decreased the oxygen permeability by 42 % (p < 0.05). Furthermore, the composite films showed enhanced antimicrobial activity against Staphylococcus aureus, Salmonella typhimurium, and Pseudomonas fluorescens. The developed KC-based composite films were applied to wrap raw beef, which significantly delayed the increase in total viable count, total volatile base nitrogen content, and thiobarbituric acid reactive substances, and prolonged the shelf-life of the raw beef by up to 10 days. These results indicated that the composite films prepared by incorporating BITC nanoemulsions into KC matrices have great antimicrobial application potential.

Effect of Hydrochloric Acid Hydrolysis under Sonication and Hydrothermal Process to Produce Cellulose Nanocrystals from Oil Palm Empty Fruit Bunch (OPEFB).

This paper presents an approach for hydrolyzing cellulose nanocrystals from oil palm empty fruit bunch (OPEFB) presented through hydrochloric acid hydrolysis under sonication-hydrothermal conditions. Differences in concentration, reaction time, and acid-to-cellulose ratio affect toward the yield, crystallinity, microstructure, and thermal stability were obtained. The highest yield of cellulose nanocrystals up to 74.82%, crystallinity up to 78.59%, and a maximum degradation temperature (Tmax) of 339.82 °C were achieved through hydrolysis using 3 M HCl at 110 °C during 1 h. X-ray diffraction analysis indicated a higher diffraction peak pattern at 2θ = 22.6° and a low diffraction peak pattern at 2θ = 18°. All cellulose nanocrystals showed a crystalline size of under 1 nm, and it was indicated that the sonication-hydrothermal process could reduce the crystalline size of cellulose. Infrared spectroscopy analysis showed that a deletion of lignin and hemicellulose was demonstrated in the spectrum. Cellulose nanocrystal morphology showed a more compact structure and well-ordered surface arrangement than cellulose. Cellulose nanocrystals also had good thermal stability, as a high maximum degradation temperature was indicated, where CNC-D1 began degrading at temperatures (T0) of 307.09 °C and decomposed (Tmax) at 340.56 °C.

Investigation of film Physical properties under various starch thermal treatments with emphasis on Retrogradation effects

This study investigated the changes in the physical properties of cornstarch-based films as they were retrogradely aged at different temperatures. Using a casting method, the films were fabricated, and their effects on the mechanical properties, thermal stability, barrier properties, and essential properties were analyzed. With prolonged aging and retrogradation periods, reductions in film thickness, solubility, water content, and water vapor permeability of 5.35%, 9.92%, 29.61%, and 20.94%, respectively, were observed. In addition, the surface roughness decreased by 44.46% for Rq (root-mean-square roughness) and 45.61% for Ra (arithmetic average roughness), while the elongation at break decreased by 72.64%. Conversely, the tensile strength, maximum degradation rate, and maximum degradation temperature increased by 116.98%, 99.5%, and 3.21%, respectively. These results provide a fundamental understanding of the changes that occur in the properties of cornstarch-based films during aging and retrogradation.

Changes in the properties of the corn starch glycerol film in a time-dependent manner during gelatinization

This study aimed to investigate the fundamental properties, solubility, mechanical properties, barrier performance, and microstructural features of films composed of corn starch and glycerol. Changes in the microstructure were analyzed to understand how they relate to the physical and chemical properties of these films. Specifically, we found that increasing the gelatinization time decreased the film thickness, solubility, water vapor permeability, and maximum degradation temperature and increased the water content. A gradual increase in the water contact angle of the corn starch–glycerol films was observed with increasing gelatinization time. This trend is likely due to the disruptive effect of gelatinization on the crystalline and amorphous structures inherent in corn starch, resulting in reduced film crystallinity, degree of order (DO) and degree of double helix (DD).

Obtaining cellulose nanocrystals by acid hydrolysis procedure; and their use as reinforcement in polylactide biocomposites

In the first step of this study, purpose was to obtain and characterize cellulose nanocrystal (CNC) particles by applying sulfuric acid hydrolysis method to the starting material of microcrystalline cellulose (MCC) fibrils. After obtaining CNC particles via acid hydrolysis procedure, various analyses (SEM, DLS, FTIR, XRD, TGA) conducted revealed that average size of round shaped CNC particles was 38 nm with −30.4 mV Zeta potential value. They had monoclinic Cellulose-I crystal structure with Crystallinity Index of 80.6% and Crystallite Size of 3.39 nm. Their maximum thermal degradation temperature was 307°C with 23 wt% residue at 800°C. In the second step, the main aim was to investigate contribution of these obtained CNC particles when they were used as nano-reinforcement in polylactide (PLA) matrix biocomposites produced by industrially compatible melt mixing and shaping techniques. Mechanical tests revealed that when only 1 wt% CNC particles were incorporated into PLA matrix, increases in flexural strength and modulus were 29% and 51%; while increases in K IC and G IC fracture toughness values were 42% and 105%, respectively. Because, high degree of hydroxyl groups and presence of sulfate half-ester groups on the surfaces of CNC particles improved the interfacial interactions between the matrix and nano-reinforcement phase, leading to efficiency in strengthening and toughening mechanisms.

EFFECTS OF POLYCHLORINATED N-ALKANES ON THE CHEMICAL STRUCTURE, MECHANICAL AND THERMAL PROPERTIES OF THE STYRENE-BUTADIENE STYRENE TRIBLOCK COPOLYMER

The development of new functional materials based on modified styrene-butadiene block copolymers will enable the creation of materials with improved resistance to gasoline, heat, light, ozone, and enhanced adhesive properties. This study investigates the influence of chlorinated paraffin on the properties of the styrene-butadiene-styrene triblock copolymer. Chlorinated paraffins (CP), complex mixtures of polychlorinated n-alkanes, were used as halogen-containing modifiers for the thermoplastic elastomer to enhance its tensile and adhesive strength and thermal properties. Composite materials based on styrene-butadiene-styrene copolymer (SBS) with various amounts of chlorinated paraffin were prepared using a solution mixing method. The analysis of the ATR/FT-IR spectra of neat SBS and SBS/CP revealed the appearance of new characteristic absorption bands at 1260, 1090, 1020, and 800 cm-1. The study determined that the amount of chlorinated paraffin strongly influenced specific properties of the examined TPE. It was observed that chlorinated paraffin improved the thermal stability of the composites. The onset temperature of degradation increased to 262 °C (a rise of 57 °C), while the maximum degradation temperature slightly increased from 463 to 467 °C. The impact of the concentration of chlorinated paraffin on the chemical structure and tensile properties was evaluated and compared to those of neat styrene-butadiene-styrene. It was estimated that SBS composites with 5 ppm. CPs are characterized by improved strength properties in comparison with the original SBS sample. For citation: Sukhareva K.V., Buluchevskaya A.D., Besedina V.O., Grosheva Yu.V., Lyusova L.R., Popov А.А. Effects of polychlorinated n-alkanes on the chemical structure, mechanical and thermal properties of the styrene-butadiene styrene triblock copolymer. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 6. P. 100-108. DOI: 10.6060/ivkkt.20246706.6973.

Optimization and prediction of thermodynamic parameters in co-pyrolysis of banana peel and waste plastics using AIC model and ANN modeling

The optimization and prediction of thermodynamic parameters including synergistic effects, and kinetic analysis in co-pyrolysis of banana peel (BP) and waste polystyrene (PS) plastic at different heating rates using ANN and AIC models has been performed. Thermogravimetric analysis was performed to determine the initial, maximum, and final degradation temperatures. The synergistic effect was studied using additive formula to determine the theoretical thermal behavior and compared with experimental TGA data. Kinetic parameters were determined by using the advanced isoconversional (AIC) model for estimation of activation energy (Eα), Criado master plot for reaction mechanism (f(α)), and compensation method for frequency factor (Aα). The analysis showed that the average activation energy values were 182.5, 140.6, and 161.8 kJ mol−1 for PS, BP, and PS+BP, respectively. It also clearly shows positive synergy in co-pyrolysis of PS and BP by reducing 11.3 % activation energy compared to that of PS alone. The frequency factor was found to be 1.0 × 1014, 1.0 × 1015, and 1.0 × 1023 s−1 for PS, BP, and PS+BP, respectively. The reaction mechanism was identified as R3, D4, and D4+R3 for PS, BP, and PS+BP, respectively. Further, the obtained kinetic parameters were used to determine the thermodynamic parameters such as enthalpy (ΔH), Gibbs energy (ΔG), and Entropy (ΔS). Finally, ANN was designed to address the co-pyrolysis behavior subjected to various heating rates. Subsequently, the trained ANN model (5 × 4×4 × 4) was employed to forecast thermal degradation behavior. Impressively, the model yielded highly accurate results with a correlation coefficient R2 > 0.998 in each case. The optimized model was further used to predict TGA data and activation energy for unknown mixtures of PS and BP. The suggested ANN model showed a great advantage in optimizing to avoid extensive experiments at various heating rates to achieve the goal.

A strong hydrogen bond bridging interface based on tannic acid for improving the performance of high-filled bamboo fibers/poly (butylene succinate-co-butylene adipate) (PBSA)biocomposites

Natural plant fiber-reinforced bio-based polymer composites are widely attracting attention because of their economical, readily available, low carbon, and biodegradable, and showing promise in gradually replacing petroleum-based composites. Nevertheless, the fragile interfacial bonding between fiber and substrate hinders the progression of low-cost and abundant sustainable high-performance biocomposites. In this paper, a novel high-performance sustainable biocomposite was built by introducing a high density strong hydrogen-bonded bridging interface based on tannic acid (TA) between bamboo fibers (BFs) and PBSA. Through comprehensive analysis, this strategy endowed the biocomposites with better mechanical properties, thermal stability, dynamic thermo-mechanical properties and water resistance. The optimum performance of the composites was achieved when the TA concentration was 2 g/L. Tensile strength as well as modulus, flexural strength as well as modulus, and impact strength improved by 22 %, 10 %, 15 %, 35 %, and 25 % respectively. Additionally, the initial degradation temperature(Tonset) and maximum degradation temperature(Tmax) increased by 12.07 °C and 14.8 °C respectively. The maximum storage modulus(E'), room temperature E', and loss modulus(E")elevated by 199 %, 75 %, and 181 % respectively. Moreover, the water absorption rate decreased by 59 %. The strong hydrogen-bonded bridging interface serves as a novel model and theory for biocomposite interface engineering. At the same time, it offers a promising future for the development of high performance sustainable biocomposites with low cost and abundant biomass resources and contributes to their wide application in aerospace, automotive, biomedical and other field.

Preparation of agar‐silica nanofilms through melt mixing: Extending beef shelf life through biodegradable packaging

AbstractThe current study used the melt mixing approach to create a variety of agar/SiO2 nanoparticle (AG/Si) nanocomposites films. Silica nanoparticles were included as a filler in different proportions, varying from 0% to 5% (w/w). The study examined how the composition impacted the chemical properties, mechanical characteristics, thermal properties, water vapor barrier, surface color, and antimicrobial capabilities. After the addition of SiO2, the tensile strength increased significantly from 30.77 to 40.97 MPa at 4% SiO2. Moreover, the presence of SiO2 was improved the contact angle from 53.81° to 63.24°, brightness of the film (L*) from 70.63 ± 3.34 up to 84.80 ± 2.26, maximum degradation temperature (Tdmax) from 315 to 317°C and melting temperature (Tm) from 109 to 125°C. In the meantime, following the integration of SiO2 content, the density of agar film dropped from 1.27 to 1.16 kg/m3. The AG/Si film effectively prevented bacterial growth and extended the shelf life of fresh beef, suggesting a novel biobased option for antimicrobial packaging film.