Formulation Composition Research Articles

Mechanical and micro-structural characterization of biodegradable coir fiber–glass sheet–charcoal reinforced polymer composite: an experimental approach

In the present investigation, the combined influence of coir, glass fibers and charcoal content on the mechanical properties of epoxy-based hybrid composites has been explored, providing insights for the potential development of advanced materials with tailored performance characteristics. Through a systematic analysis of the mechanical properties (tensile strength, Young's modulus, flexural strength, flexural modulus, and Brinell hardness number), various composite formulations were evaluated to discern their performance characteristics. The study reveals significant variations in mechanical properties across different composite configurations, highlighting the critical role of fiber type and charcoal content in determining the materials’ performance. Notably, composites featuring alternating layers of glass and coir fibers exhibit superior tensile and flexural strengths, underscoring the synergistic effects of hybridization. Conversely, the introduction of charcoal as a reinforcement agent leads to deterioration in the mechanical properties, indicating a trade-off between the reinforcement and other desirable attributes. These findings offer valuable insights for the strategic design and engineering of advanced materials tailored to specific applications, paving the way for the development of high-performance epoxy-based hybrid composites with enhanced mechanical properties and durability.

Physically Cross-Linked PVA Hydrogels as Potential Wound Dressings: How Freezing Conditions and Formulation Composition Define Cryogel Structure and Performance

Objectives: Hydrogels produced using the freeze–thaw method have demonstrated significant potential for wound management applications. However, their production requires precise control over critical factors including freezing temperature and the choice of matrix-forming excipients, for which no consensus on the optimal conditions currently exists. This study aimed to address this gap by evaluating the effects of the above-mentioned variables on cryogel performance. Methods: Mechanical properties, absorption capacity, and microstructure were assessed alongside advanced analyses using differential scanning calorimetry (DSC) and low-field nuclear magnetic resonance relaxometry (LF TD NMR). Results: The results demonstrated that fully hydrolyzed polyvinyl alcohol (PVA) with a molecular weight above 61,000 g/mol is essential for producing high-performance cryogels. Among the tested formulations, an 8% (w/w) PVA56–98 solution (Mw~195,000; DH = 98.0–98.8%) with 10% (w/w) propylene glycol (PG) provided the best balance of stretchability, durability, and low adhesion. Notably, while −25 °C is often used for cryogel preparation, freezing the gel precursor at −80 °C yielded superior results, producing materials with more open, interconnected structures and enhanced mechanical strength and elasticity—deviating from conventional practices. Conclusions: The designed cryogel prototypes exhibited functional properties comparable to or even surpassing commercial wound dressings, except for absorption capacity, which remained lower. Despite this, the cryogel prototypes demonstrated potential as wound dressings, particularly for use in dry or minimally exuding wounds. All in all, this study provides a comprehensive analysis of the physicochemical and functional properties of PVA cryogels, establishing a strong foundation for the development of advanced wound dressing systems.

Energy Harvesting Using Optimized ZnO Polymer Nanocomposite-Based 3D-Printed Lattice Structure

A 3D-printable polymer can provide an effective solution for developing piezoelectric structures. However, their nanocomposite formulation and 3D printing processability must be optimized for fabricating complex geometries with high printability. In the present study, we optimized the 3D-printable piezoelectric composite formulation for developing complex geometries by an additive manufacturing approach. The zinc oxide (ZnO) nanomaterial was synthesized by the hydrothermal method. The ZnO loading in the 3D-printed flexible resin was optimized to exhibit good interfacial adhesion and enable 3D printing. The lattice structure was fabricated to improve the piezoelectric response compared with the solid structure. The lattice structure block printed with 10 wt% ZnO showed a good piezoelectric response, with a linear increase in the generated output voltage for an increase in force. The maximum power density of 0.065 μW/cm2 was obtained under 12 N force at 1 Hz. The fabricated structure generated a peak–peak voltage of ~3 V with a foot heel strike.

UV Exposure Time Optimization for Enhanced Conversion, Hardness, and Flexural Strength in UDMA/TEG-DMA Composite Resins

This study examines the effects of varying ultraviolet (UV) exposure times on the properties of UDMA/TEG-DMA composite resins, focusing on degree of conversion, surface morphology, water absorption, shrinkage, hardness, and flexural strength. Composite resin samples were exposed to UV light for 30, 60, 90, and 120 min. The degree of conversion was assessed using Fourier Transform Infrared Spectroscopy (FTIR). Surface morphology was analyzed via Scanning Electron Microscopy (SEM). Water absorption and shrinkage were measured following standard procedures, while mechanical properties, including hardness and flexural strength, were evaluated using a Vickers hardness tester and a 3-point bending test, respectively. The results indicate that a UV exposure time of 90 min optimizes the composite resin properties, achieving the highest degree of conversion at 77 %, optimal surface morphology, minimal water absorption and shrinkage, and superior mechanical properties, including maximum flexural strength and hardness. In contrast, both shorter and longer UV exposure times detrimentally affected these properties, with prolonged exposure causing thermal degradation and reduced performance. This research underscores the importance of precise UV curing time control to enhance the performance and durability of UDMA/TEG-DMA composite resins, providing valuable insights and practical guidelines for their application in dental and industrial fields. HIGHLIGHTS The incorporation of UDMA/TEG-DMA in composite resin formulations significantly enhanced mechanical properties such as flexural strength and modulus. Exposure to UV light affected the degree of conversion of the resin, impacting its polymerization kinetics and potentially influencing long-term durability. The study revealed notable changes in surface morphology, indicating potential implications for bonding characteristics and aesthetic outcomes. Investigating water absorption and shrinkage behavior provided insights into material stability and dimensional changes over time, critical for clinical longevity and patient satisfaction. GRAPHICAL ABSTRACT

Enhanced Interfaces for High-Temperature Purposes—Practical Methodology and Characterization

The current study is focused on devising treated diatomite interfaces with the robustness and boiling water resistance necessary for high-temperature purposes. This work describes the synthesis methodology of the diatomite-based coatings, which followed the production of a composite formulation composed by treated diatomite powder dispersed in an epoxy resin matrix. After its preparation, the suspension was applied via the dip-coating technique over AISI-304 stainless-steel foils, which, after being air dried, underwent a post-curing treatment. Also, the interfaces were characterized by diverse techniques such as scanning electron microscopy and optical tensiometry. Apart from this, their thermophysical properties like thermal conductivity were also determined. Further, the physical and chemical durability of the interfaces was also evaluated via the elaboration of robustness tests including abrasion resistance, adhesion strength, solid impact resistance, and solvent resistance. The results showed satisfactory resistant interfaces, and with a wettability characterized by contact angles superior to 150°. Also, the interfaces confirmed improved durability when immersed in boiling water at 1 atm, since their wetting characteristics and durability remained nearly unaltered after 762 h of testing. Additionally, the synthesized interfaces possessed self-cleaning ability and chemical and thermal shock aging resistance. Generally, the fundamental outcomes of this work point out the suitability of the produced diatomite-based interfaces to be explored in high-temperature applications like flow boiling, pool boiling, and condensation. In terms of practicality, the method of preparation of the interfaces was a relatively easy and rapid approach to obtaining enhanced wettability and resilient interfaces, and with the required adaptations like the ratios between the raw materials, its suitability for large-scale applications makes this an appealing option.

Lyotropic liquid crystal and self-emulsifying drug delivery systems nanoparticles as artesunic acid and praziquantel carriers: An innovative approach for formulation of anti-malaria and schistosomicidal drugs

Praziquantel (PZQ) is the drug of choice for treating cestode and trematode infections, and it is currently the only option against schistosomiasis. Artesunic acid (AcART) is effective against several parasites and has emerged as an alternative for schistosomiasis treatment. However, AcART and PZQ have limited bioavailability due to poor water solubility, low permeability, and rapid cell clearance. To address these challenges, this study aimed to develop self-emulsifying drug delivery systems to develop SEDDS and NPs-LLC to overcome the low water solubility affecting AcART and PZQ bioavailability. The study involved validating the HPLC analytical methodology for AcART, SEDDS, and NPs-LLC formulations, and conducting physicochemical characterization and ex-vivo intestinal permeation assays. The composition of formulations was determined by the solubility balance of AcART and PZQ. The drug content ranged between 83 and 90 %. The anionic zeta potential was attributed to Myverol®, and the particle diameter increased slightly after the drug incorporation, while the polydispersity index indicated the relatively narrow particle size distribution. Additionally, the DSC thermogram confirmed that PZQ and AcART are in solution within SEDDS and NPs-LLC. The FTIR analysis suggests that components of SEDDS and NPs-LLC and drugs do not react to form new chemical species. The selection of specific compound formulations was based on achieving the best solubility balance. The nanostructures were stable and exhibited a surface charge favorable to mucosal permeation, with slightly superior performance for SEDDS. The innovative formulations, SEDDS and NPs-LLC, are suitable and effective carriers for AcART and PZQ.

Exploring the potential of rigid polyurethane foam waste in structural lightweight concrete

The structural lightweight concrete is gaining significant interest in the research community due to its reduced dead load. The reduction in the self-weight not only lowers the gravity load but can also lower the seismic demands for the structural members and hence can potentially reduce the overall cost. This study examines the feasibility of developing a sustainable structural lightweight concrete by utilizing rigid polyurethane foam waste as coarse aggregates (5–10 mm). The silica fume was incorporated as a cement replacement to enhance the compressive strength of the mix. A total of three composite mix formulations consisting of polyurethane foam, cement-coated polyurethane foam, and pumice (control specimens) as coarse aggregates were tested. The testing was performed for workability, compressive strength, flexural strength, elastic modulus, absorption, permeable voids, chloride-ion penetration, freeze and thaw resistance, and drying shrinkage. The results achieved for elastic modulus, chloride ion penetrability, and drying shrinkage, were meeting the minimum requirements of the standards making this composite suitable for the structural application. The results revealed that uncoated polyurethane based lightweight aggregate concrete resulted in an air-dry density of 1829 kg/m3 with the corresponding compressive strength of 19.5 MPa and flexural strength of 2.78 MPa at 28 days. Besides, the polyurethane-based lightweight concrete also showed lower internal structure damage against freeze and thaw action, along with improved thermal conductivity.

Fabrication of Uniform Melatonin Microparticles Potentially for Nasal Delivery: A Comparison of Spray Drying and Spray Freeze Drying.

Insomnia is a major health concern, and melatonin (MLT) is key for initiating sleep. Delivering MLT nasally can enhance brain bioavailability by targeting the olfactory region. This study aimed to fabricate MLT embedded microparticles for nasal delivery. MLT-cyclodextrin (CD) derivatives complex microparticles (MCCMPs) were fabricated by spray drying and spray freeze drying MLT and CD derivative solutions. Phase solubility and 1H-1H ROSEY NMR analysis assessed MLT-CD assembly. The effects of formulation compositions and process parameters on microparticle structural attributes were investigated. The in vitro nasal release and deposition performances were evaluated by a modified paddle-over-disk apparatus and 3D-printed nasal cavity cast, respectively. Sodium sulphobutylether-β-cyclodextrin (SBE-β-CD) exhibited the best complexation ability with MLT, with the indole structure of MLT included in its cavity. Spray dried MCCMPs showed dense structure with high density, while the spray freeze dried counterpart showed the brittle and porous structure with low density. Despite the porous structure may promote the release rate of spray freeze dried samples, the high hydrophilicity of the CD derivative overshadows this advantage. Samples prepared by spray drying not only exhibited rapid release rates but also could deposit more effectively in the olfactory region, as they avoid breakage due to their higher mechanical strength. The optimal sample showed ~ 86.70% of the MLT released at 20min and ~ 10.57% of the deposition fraction in the olfactory region. This work compares MCCMPs fabricated by spray drying and spray freeze drying, providing the optimal formulation and process combinations.

The Role of Formulations in the Ageing Process of Vinyl Acetate Based Emulsion Films: A Multivariate Approach

Vinyl acetate (VAc)-based emulsions represent one of the main media used by modern and contemporary artists. Their long-term behaviour is still not completely understood, especially due to the scarce knowledge on the influence of other compounds in the formulation, which may impact ageing over time. Besides the polymer backbone based on vinyl acetate, other co-monomers and additives can be added to the emulsion to alter the final film’s physical, chemical, and optical properties. By extension, the formulation will also impact the long-term stability of artworks and objects on which it has been applied, as well as possible current and future conservation interventions such as cleaning. For those reasons, studies shedding light on the correlation between composition and long-term stability are largely necessary. In this study, different emulsions, including homopolymers, copolymers, plasticised, and un-plasticised compositions, were gathered and artificially aged. A multivariate analyses approach based on the application of principal component analyses (PCA) and hierarchical cluster analyses (HCA) was employed for the first time on the combination of data obtained by pH, contact angle (CA), colour measurements, Fourier transform infrared spectroscopy in attenuated total reflection (FTIR-ATR), and size exclusion chromatography (SEC). This approach helped to highlight the changes that occurred during ageing and find correlations with the formulation compositions. The results further sustain the thesis that not all vinyl acetate-based emulsions are chemically the same and that their formulation deeply impacts their long-term behaviour.

Partially defatted chia flour as a novel ingredient for gluten-free breadmaking: Improving sustainability, nutrition and consumer liking

Partially defatted chia flour (DCF) is a valuable food ingredient in the context of a circular economy, with the potential to improve the nutrient and bioactive contents of gluten-free foodstuff. Thus, this study assessed the effects of interactions between DCF and water content (W) on the physical and sensory properties of gluten-free bread (GFB) and defined, using the response surface method, the composition of formulations that enable quality optimization. A rotatable central composite design was used to assess the main and interaction effects of DCF (ranging from 0 to 28% on a flour basis (fb) and W (ranging from 100 to 200% fb) on the physical properties and consumer linking of rice flour based GFB. The resulting models indicated that higher DCF or W levels diminished the bread quality. However, different W and up to 17.2% DCF can be used to prepare bread with high consumer liking (scores ≥7 for all assessed characteristics, on a scale of 10). The formulation prepared with 0% DCF and 135.5% W (fb) had the highest degree of liking (varying from 8.3 to 9.0). However, when incorporating up to 9.8% DCF and 135.5% W, a high liking can be maintained (scores 8.0 to 8.5 for all characteristics). Acceptable GFB with up to 17.2% DCF in the formulation can be obtained if the W content is adjusted (135 to 139.7% fb). Incorporating 17.2% DCF doubles the fiber content of the GFB. Therefore, DCF is an alternative ingredient to obtain nutritionally improved and acceptable GFB.

Investigating the effects of formulation variables on the disintegration of spray dried amorphous solid dispersion tablets

Amorphous solid dispersion (ASD) tablets based on hydrophilic polymer carriers may encounter disintegration challenges. In this work, the effect of different formulation composition variables on the ASD tablet disintegration performance was systematically studied. GDC-0334: copovidone (PVPVA) 60: 40 ASD prepared by spray drying was selected as the model ASD system. The effects of ASD loading, filler type and ratio, disintegrant type and level were then investigated using tablets made by direct compression process. Tablet disintegration time increased with the increase of ASD loading, especially when ASD loading exceeded 50 %. At the same tablet solid fraction, when lactose was used as the soluble filler, faster tablet disintegration time was observed compared to the tablets with mannitol as the soluble filler. Among the three tested disintegrants, croscarmellose sodium performed the best in facilitating the ASD tablet disintegration, followed by sodium starch glycolate, and crospovidone was the poorest. When croscarmellose sodium was used as the disintegrant, 5 % level was sufficient to enable ASD tablet disintegration at 60 % ASD loading and further increase of croscarmellose sodium level to 8 % did not provide additional benefit. Water uptake experiments were performed on selected tablets and the results demonstrated a positive correlation with tablet disintegration time, indicating water penetration is a major contributing step for the disintegration of our ASD tablets. Overall, this work provides a rationale for excipient selection and insights into building a platform formulation approach for developing immediate-release ASD tablets.

Particle formation in response to different protein formulations and containers: Insights from machine learning analysis of particle images

Subvisible particle count is a biotherapeutics stability indicator widely used by pharmaceutical industries. A variety of stresses that biotherapeutics are exposed to during development can impact particle morphology. By classifying particle morphological differences, stresses that have been applied to monoclonal antibodies (mAbs) can be identified. This study aims to evaluate common biotherapeutic drug storage and shipment conditions that are known to impact protein aggregation. Two different studies were conducted to capture particle images using micro-flow imaging and to classify particles using a convolutional neural network. The first study evaluated particles produced in response to agitation, heat, and freeze-thaw stresses in one mAb formulated in five different formulations. The second study evaluated particles from two common drug containers, a high-density polyethylene bottle and a glass vial, in six mAbs exposed solely to agitation stress. An extension of this study was also conducted to evaluate the impact of sequential stress exposure compared to exposure to one stress alone, on particle morphology. Overall, the convolutional neural network was able to classify particles belonging to a particular formulation or container. These studies indicate that storage and shipping stresses can impact particle morphology according to formulation composition and mAb.

Development of a technological solution aimed at improving the consumer properties of a new fish culinary product enriched with chondroitin sulfate of thorny skate

The paper presents the results of developing a fish culinary product (thorny skate meat mixed with Atlantic cod meat, baked with potatoes and mushrooms in a cream sauce) enriched with chondroitin sulfate contained in the meat and cartilage of the wings of thorny skate. Atlantic cod, more familiar to the Russian consumer and successfully complementing the skate's meat with amino acid composition, has been chosen as an additional fish raw material. Thorny skate belongs to the underutilized fishing facilities of the Northern Basin. The meat of its wings contains up to 1.5 % urea, which worsens its organoleptic properties. To solve this problem, it was previously proposed to use short-term preliminary heat treatment (PHT) of skate's wings by blanching them in water at a temperature from 93 to 96 °C for 1–3 minutes, which guarantees a fourfold decrease in the mass fraction of urea in the meat, relative to the initial content, below the organoleptic perception of the consumer. PHT also facilitates the cutting of the skate's meat. The formulation and technology of a combined fish culinary product is proposed, packaged and completely ready for consumer's use. To prolong the shelf life up to 120 days, it is proposed to subject the product to shock freezing with subsequent storage at a temperature no higher than minus 18 °C. To solve the problem of delamination of cream sauce during storage and to improve the consumer properties of the product, an experimentally based technological solution is proposed – the introduction of oat flour in the composition of the sauce formulation as a thickener and structure-forming agent in an amount of 3.5 % per total mass of sauce.

Self-propagating high-temperature synthesis of AlN–TiC powder composition using sodium azide and C2F4 fluoroplastic

Producing powder compositions using conventional processing technology can lead to the formation of large agglomerates and, therefore, makes it difficult to obtain a uniform microstructure. The production of composites by self-propagating high-temperature synthesis can reduce costs and the number of technological stages, as well as lead to obtaining composites that are more homogeneous. Synthesis by the combustion of mixtures of powder reagents of sodium azide (NaN3), fluoroplastic (C2F4), aluminum and titanium with different ratios of reagents in a nitrogen gas atmosphere at a pressure of 4MPa was used for the production of a highly dispersed powder ceramic AlN–TiC composition. Thermodynamic calculations have confirmed the possibility of synthesis of AlN–TiC compositions of different formulations in combustion mode. The dependences of temperature and combustion rate on the composition of the initial mixtures of reagents were experimentally determined for all stoichiometric reaction equations. The study have shown that the experimentally found dependences of combustion parameters on the ratio of the initial components correspond to the theoretical results of thermodynamic calculations. The formulation of the synthesized composition differs from the theoretical composition by a lower content of target phases and the formation of Al2O3, Na3AlF6 and TiO2 side phases. The powder composition consists of aluminum nitride fibers with a diameter of 100–250nm and ultradisperse particles of predominantly equiaxed and lamellar shapes with a particle size of 200–600nm. As the combustion temperature increases to produce the largest amount of titanium carbide phase, the particle size increases to the micron level.

Optimization and Appraisal of Nintedanib-Loaded Mixed Polymeric Micelles as a Potential Nanovector for Non-Invasive Pulmonary Fibrosis Mitigation.

Nintedanib (NTD), a triple tyrosine kinase receptor inhibitor, is the recommended first-line tackling option for idiopathic pulmonary fibrosis (IPF). Nevertheless, the adequacy of NTD is curtailed by issues associated with its low solubility, first-pass effect, poor bioavailability, and liver toxicity. The objective of our work was to develop a non-invasive intratracheal (i.t.) nanoparadigm based on NTD-loaded polymeric mixed micelles (NTD-PMMs) that can effectively treat IPF by sustaining the release of NTD, and snowballing its bioavailability, solubility, and efficacy. Design-Expert® software was used to optimize various NTD-PMMs formulations via Box-Behnken design adopting the thin-film hydration technique. The optimum formulation was chosen and in vivo tested in a rat model to explore its comparative bioavailability and toxicity. The formulation composition with 309.217 mg of Soluplus, 150 mg of Tween 80, and 40 mg of sodium deoxycholate was found to fulfill the requisites of an optimum NTD-PMMs formulation. The optimum NTD-PMMs formulation divulged 90.26% entrapment efficiency with a surface charge of -14.72 mV and a nanoscale diameter of 61.36 nm. Also, it substantially sustained the release of NTD by 66.84% after 24 h and manifested a pronounced stability. In vivo histopathology investigations verified the safety of NTD-PMMs delivered intratracheally. Moreover, pharmacokinetic analyses disclosed accentuated relative bioavailability of the optimized NTD-PMMs by 2.4- and 3.82-fold as compared with both the i.t. and oral crude NTD suspensions, respectively. Overall, the current results elicited the potential of PMMs to serve as a promising pulmonary nanovector for the targeted delivery of NTD.

Temperature mapping of milling by dual centrifugation: A systematic investigation

Using low quantities of drug compounds is often favorable in the early stages of drug development, especially for what require a large screening investigation to define the final formulation composition, such as nano- and microsuspensions. For that reason, the dual centrifugation approach has in the recent years been used due to its reproducible and fast-milling capacity with 40 samples in 2 mL vials simultaneously without the addition of cooling breaks due to a built-in cooling system. Nonetheless, heat can be dissipated into the samples during high-intensity milling, resulting in increased sample temperatures that potentially can affect thermolabile compounds and potential influence the obtained suspensions in the screening experiments if the used stabilizer has temperature dependent variations in the performance. Hence, a systematic investigation of the influence of different process parameters on the heat dissipation in samples during milling by the dual centrifugation approach was performed in the present study. It was found that the milling speed had the highest impact on the final sample temperature, but also other parameters, such as the bead loading, bead size, and placement in the centrifuge during milling had significantly influenced the final mean temperature of the milling media. Higher temperatures were obtained with higher bead loadings, i.e., 3000 mg milling beads/mL and milling speeds (1500 rpm), and when smaller milling beads, i.e., 0.1 mm, were used during production. The study further showed that higher temperatures were measured for samples located on the bottom disk during milling, and also when located on the outer placement on the sample disk. Upscale investigations showed immensely increased sample temperatures (almost up to boiling point) when samples were prepared under similar formulation parameters and milling speed as small-volume vials. Furthermore, the study indicated that the addition of drug compounds during suspension preparation decreased the final sample temperature compared to samples that only contained purified water due to energy absorption of the drug compound.

Natural Rubber Latex Wastes from Balloon Production as Valuable Source of Raw Material: Processing, Physico-Mechanical Properties, and Structure

This study explores the potential for recycling natural rubber (NR) latex waste from balloon production through the devulcanization and revulcanization processes. The mechanical devulcanization of colored latex balloon waste was conducted, followed by revulcanization using a sulfur-based system. The reclaimed rubber’s properties, including crosslink density, tensile strength, and abrasion resistance, were compared with those of virgin NR. The results demonstrate that the reclaimed rubber maintains a crosslink density close to that of virgin NR. Hardness and abrasion resistance were comparable, indicating successful material recovery. Structural analyses, including FTIR and SEM microscopy, revealed that the devulcanization process effectively allowed for successful revulcanization. This study concludes that NR latex waste can be effectively recycled and reused in rubber composite formulations, offering a sustainable approach to waste management in the rubber industry and contributing to developing eco-friendly materials. In the context of this research, integrating advanced chemical and physical methods, such as solubility parameter calculations and enhanced devulcanization techniques, could further optimize the devulcanization process. These methods quantitatively enhance the efficiency of material recovery, offering a path to more sustainable recycling practices. The findings suggest that combining such advanced methodologies could significantly improve recycled NR latex’s overall performance and applicability in industrial applications.

Interpretable machine learning‐assisted strategy for predicting the mechanical properties of hydroxyl‐terminated polyether binders

AbstractHydroxy‐terminated polyether (HTPE) binders are attractive in the weapons materials and equipment industry for their insensitive properties and flexibility. We propose an interpretable machine learning‐assisted modeling strategy to predict the mechanical properties of HTPE binders for the first time using machine learning methods. In this strategy, the effects of formulation composition, multiscale characterization, preparation conditions, and mechanical experimental conditions are evaluated on the mechanical properties of HTPE binders. As part of the study, three different techniques were used to predict material properties: bag‐based methods (Extra Random Tree, Random Forest), boosting‐based methods (XGBoost, CatBoost, and Gradient Boosted Regression), and Artificial Neural Networks (MLPs), all of which were highly accurate in predicting material properties. Based on this, SHAP analysis is used to explain how these influencing factors influence the material properties. An efficient method for examining HTPE binders formulations is provided by this strategy.

Optimization of nano-filler and silane treatment on mechanical performance of nanographene hybrid composites using RSM and ANN technique

This study utilized response surface methodology (RSM) and artificial neural networks (ANN) to optimize the formulation of polymer composites with three key variables: silane concentration, silane dipping time, and the number of nanoparticles. RSM and analysis of variance were employed to explore the effects of these variables on the composite’s mechanical properties, while ANN was used for analyzing complex interactions between parameters. The results reveal a significant correlation between the predicted and actual response values derived from the models. Notably, silane treatment of fiber was identified as the primary factor influencing the composite’s flexural strength. The study found that all fiber-related properties substantially affected both flexural strength and hardness, with silane dipping time being the most critical factor. Additionally, incorporating nanoparticles improved the fiber matrix’s strength by enhancing agglomeration. ANN achieved a 95% accuracy in predicting flexural strength and hardness. Comparisons among experimental data, the regression model, and ANN confirmed the robustness of the ANN predictions. The optimal composition identified for flexural strength was 5 wt % nanoparticles, 10 wt % silane treatment, and a 20-min dipping time. For hardness, the ideal formulation was 5 wt % nanoparticles, 15% silane treatment, and a 20-min dipping time in silane. This comprehensive approach offers a refined method for developing high-performance polymer composites with tailored properties.

CROSSLINK DENSITY AND ITS DISTRIBUTION IN HEAT AND OIL RESISTANT ELASTOMERS BY DOUBLE QUANTUM NUCLEAR MAGNETIC RESONANCE

ABSTRACT Double quantum (DQ) nuclear magnetic resonance (NMR) was used to characterize the crosslink density, crosslink density distribution, and defect level in a series of heat and oil resistant elastomers. A wide range of defect levels, crosslink densities, and crosslink density distributions was measured, and results depended on elastomer type and compound formulations, including the vulcanization system. The sol fraction defect level generally correlated with the concentration of added plasticizer in the formulation. The presence of polar side chains appeared to cause additional dynamic contributions to the dangling chain end fraction. The large differences in elastomer composition and rubber formulations prevented meaningful correlation of the measured crosslink densities with the low strain modulus. Fast Tikhonov regularization and log normalization fitting of the corrected DQ build-up curve was extremely useful to provide insight into the modality and widths of the crosslink density distributions. A high degree of heterogeneity of the crosslink network of heat and oil resistant elastomers was found. Crosslink density distributions were explained in terms of the polymer chain structure comprised of monomer sequencing coupled with the position of the crosslinking sites. The type of vulcanization system had a lesser effect of the nature of the crosslink density distribution. The primary polymer chain crosslinking sites may become segregated from the continuous phase due to polarity differences seen in the microstructure of oil and heat resistance elastomers. The development of such micromorphologies can favor curative partitioning. The sole use of DQ NMR can provide valuable insight into the nature of the polymer chain structure and crosslink network in rubber.