Journal of Composites and Biodegradable Polymers

Experimental and Simulation Studies on the Warpage of Coreless Substrate Under Multiple Laminating Process

Wed, 18 Jun 2025 00:00:00 +0000

Substrate warpage caused by curing process and thermal cycling is a very important issue in electronic packaging. Considerable efforts have been made to develop methods for predicting, measuring and controlling warpage. The current work focuses on the warpage and stress distribution of coreless substrates during multiple laminating process. Flexural property tests and thermal-mechanical measurements were carried out with samples cured under different lamination cycles in order to investigate the influence of in-plane anisotropic properties on the warpage. The results show that, with the increase of lamination cycles, both flexural modulus and coefficient of thermal expansion (CTE) of the laminates increase. Further, the cure shrinkage of the prepreg during curing, the effects of cure cycles and copper residuals on substrate warpage were examined through finite element analysis. The simulation results show that, after undergoing multiple curing processes, the thermoelastic parameters of the prepreg exhibit a complex relationship with the warpage and stress distribution of the substrate. Due to the increase in the number of material layers, the overall rigidity of the substrate is enhanced, and the average internal stress in the substrate structure decreases. This results in a downward trend in substrate warpage during multiple lamination processes.

Based on the Finite Element Method (FEM) simulation results for the multiple laminating process, some modifications can be made regarding the substrate design and material selection, to optimize fabrication process of coreless substrate.

Study on Copper Protection in H2S-rich Marine Environments using SAMs from Sargassum Extract

Prescilla Lambert, Mahado Said Ahmed, Mounim Lebrini — Mon, 06 Oct 2025 00:00:00 +0000

Corrosion is a complex and progressive degradation process that occurs when an aggressive external agent attacks a metal and is known to cause significant harm to materials, the environment, and metals. One important factor in these physicochemical phenomena is the atmosphere. Factors like temperature, humidity, and salinity are relevant. For most materials, the marine environment is the ideal example of an environment that is naturally aggressive. Because few metals can resist it, they must be protected. For instance, when copper corrodes in an alkaline environment, copper oxide forms a protective film on the metal's surface, reducing its ability to attack. Nevertheless, the metal eventually deteriorates because of the instability of the surrounding environment, so this solution is only temporary. These days, plants-based inhibitors represent a real source of robust, long-lasting protection. They can function as natural inhibitors of metals and their alloys due to their very beneficial natural characteristics. Therefore, the focus of this work is on how Sargassum fluitans III self-assembled monolayers (SAMs) inhibit copper corrosion in coastal environments. When copper is submerged directly in the inhibiting solution, the extract successfully prevents copper corrosion, according to the findings of surface analysis and electrochemistry. In this article, for example, it was demonstrated that sargassum extract halves the loss of copper thickness, reducing it from 8.00±0.61 mm to 4.76±0.52 mm on a site heavily exposed to sea salts.

Nano-Silica and Biopolymer Hybrid Composites for Sustainable (Bio)Organic Sensing Applications

Amar Yasser Jassim, Wesam R. Kadhum, Ehsan kianfar — Wed, 12 Mar 2025 00:00:00 +0000

In the chemical industry, the development of sustainable economic strategies for accessing products with high added value from substitutes and cheaper sources is now more of a challenge. Silica is one of the most frequently used chemicals and is often used in many industrial applications, such as in toothpaste as a cleaning agent, in the rubber industry, and as a reinforcing material. This essay summarizes alternative approaches for the synthesis of salt and hybrid geocide materials. So far, these phases have been synthesized from molecular silane precursors via water-splitting sol-gel chemistry or chlorinated silane incineration processes, and thus indirectly from quartz sand. However, quartz sand is a non-renewable resource, and the scarcity of actual sand is becoming increasingly problematic for various processes in the chemical industry. In fact, quartz sand is the second most common raw material in the world, and its availability has a major impact on many production processes. B. Healthcare or electronic devices. In the actual context of sand shortage, the drafting of silica-based materials is increasingly attracting interest from alternative sources. This summary article discusses the new possibilities for access to bio sourcing and material-based sources such as renewable starting materials, electrical and electronic equipment in waste equipment, or fluorosilicic acid, a by-product of the phosphate industry. Silica must be considered a valuable raw material, and it demonstrates that alternative production processes from renewable resources, as well as cyclical lifetime assessments and valuable recycling strategies for these materials should be considered in consideration of the creation of sustainable and periodic production processes. The exciting science of organic devices has brought about a completely new stage of feasible bio detecting innovation, which offers a prospective horizon for applications in therapeutic diagnostics and organic checking. This audit report provides a thorough analysis of the remarkable advancements in organic electronic devices and their potential for bio detection applications. The need for more accurate, more affordable, and more capable sensors was felt as a result of global scientific advancements, the development of electronic equipment, and the enormous changes that occurred over the last several decades. In order to be sensitive to minute amounts of gas, heat, or radiation, sensors with high affectability are used nowadays. It is necessary to disclose underused materials and devices in order to increase the affectability, capability, and accuracy of these sensors. Due to their small and nanoscale estimates, Nano sensors—sensors that are nanometers in size—have exceptionally high precision and responsiveness, allowing them to react without a doubt to the proximity of many gas particles. Compared to conventional sensors, Nano sensors are inherently more delicate and smaller.

Fused Deposition Modelling of Wood-Plastic Composites: Materials, Processes, and Future Directions

Wan Sharuzi Wan Harun — Wed, 22 Oct 2025 00:00:00 +0000

Fused Deposition Modelling (FDM) of Wood-Plastic Composites (WPCs) offers a compelling pathway towards sustainable manufacturing. However, the progression from prototyping to functional components is governed by a fundamental conflict: the pursuit of high wood content for sustainability directly opposes the thermo-rheological constraints of the extrusion process. This review critically analyses this conflict, arguing it is the primary source of the two main defects that limit structural applications: severe mechanical anisotropy from weak interlayer adhesion, and multi-scale porosity inherent to both the feedstock and the printing process. By deconstructing the material systems and process-structure-property relationships, this review synthesises current strategies to mitigate these challenges. Ultimately, this review argues that the future of the field depends on a paradigm shift towards intelligent manufacturing, integrating predictive modelling with novel bio-based materials and leveraging the unique properties of WPCs for functionally graded components and environmentally responsive 4D printing.

Experimental Behavior of One-Way RC Ultra-Thin Slabs Retrofitted with Post-Installed NSM CFRP Rods

Alaa N.A. Al-Nussairi, Ahmed S.H. Suwaed — Wed, 22 Oct 2025 00:00:00 +0000

This study evaluates the flexural behavior of ultra-thin (50 mm) one‑way reinforced‑concrete (RC) slabs retrofitted with near‑surface mounted (NSM) carbon‑fiber‑reinforced polymer (CFRP) rods under quasi‑static loading. T300‑grade CFRP rods (≈4 mm diameter) were bonded in pre‑cut 7 mm × 7 mm grooves using a two‑part epoxy. As a proof-of-concept experimental baseline, three simply‑supported specimens (1000 mm × 500 mm × 50 mm) were tested in a six‑point bending configuration (four applied loads + two reactions): two conventional controls and one strengthened slab. A load‑control rate of ~15 kN/min was applied; the controls were cycled twice and the strengthened slab four times. Relative to the average of the two control specimens, the strengthened slab achieved ~+103% ultimate load (49.4 kN vs 24.3 kN) with a ~24% reduction in ductility (μΔ = 2.4 vs 3.15). Hysteretic dissipation, computed as loop area per cycle, was markedly higher for the strengthened slab; cycle‑matched comparisons (cycles 1–2) are reported alongside cumulative values. The results show that NSM CFRP can markedly enhance capacity and energy absorption of very thin one‑way slabs, with a trade‑off in ductility that should be considered in design.

Determining the Significance of Surface Roughness and Hardness Outputs of Grinding Cylinders Specifically for Laser Processing Parameters

Abdullah Zekai Kivrim, Omer Sinan Sahin, Betul Ergun, Mehmet Bagci — Sat, 25 Oct 2025 00:00:00 +0000

Surface roughness and hardness, critically important in industrial applications, are parameters that affect the performance and functionality of cast iron materials, particularly in various sectors. White cast iron is widely used in food milling due to its superior hardness and wear resistance. In parallel with all these advantages, grinding cylinders made of white cast iron wear to a certain extent due to the grinding of products such as wheat, barley, and coffee beans, necessitating periodic surface treatment. Laser processing has become widely used in recent years to modify the surface properties of metallic and composite materials. This experimentally significant study focused on investigating the effects of laser processing parameters on the surface roughness and hardness of grinding cylinders made of white cast iron. It was concluded that by using 10, 30 and 50 W, the desired hardness and roughness can be achieved by correctly selecting the process parameters. At the end of the experimental process, depending on the effect of power parameter variability, microscopic images showed a smooth surface texture, regional molten surface fluctuations and microcrater results in the presence of irregular solidification in the upper layer.

Progress in Structural Design and Multifunction of Bio-based Epoxy Resin Composites Containing Dynamic Bonds

Yating Wang, Xigao Jian, Zhihuan Weng — Mon, 17 Nov 2025 00:00:00 +0000

Epoxy thermosets are widely used in coatings, adhesives, and composites because of their excellent mechanical strength, chemical resistance, and dimensional stability. However, their petroleum-based origin and permanent crosslinking raise concerns regarding environmental impact and human health. Bio-based epoxy systems and dynamic covalent chemistry (DCC) have therefore emerged as promising strategies to achieve sustainability and recyclability. Although many studies have explored dynamic epoxy networks, most reviews emphasize resin-level properties rather than their behavior in composite systems. This review aims to provide a focused and comprehensive overview of bio-based epoxy composites containing dynamic bonds, clarifying how dynamic exchange mechanisms influence molecular design and multifunctional performance. Key findings highlight the synergistic roles of different dynamic chemistries in enabling reprocessability, self-healing, recyclability, and enhanced structural robustness. By identifying structure–property relationships across various composite strategies, this review fills a critical gap in the literature and offers guidance for the rational design of next-generation biodegradable epoxy composites.

Analytical, Experimental, and Finite Element Analysis of Buckling and Wrinkling Failure Modes in Carbon/PVC Sandwich Panels

João Alberto Günther Neto, Felipe Ruivo Fuga, Ricardo de Medeiros — Thu, 20 Nov 2025 00:00:00 +0000

Carbon fibre–reinforced PVC foam sandwich composites are widely used in aeronautical and marine structures due to their high strength-to-weight ratio. However, the stiffness mismatch between face sheets and cores may lead to local buckling modes such as face wrinkling and shear crimping when subjected to compressive loads. Therefore, this study presents a comprehensive investigation on the interaction between global and local buckling modes for sandwich beam structures with lengths varying between 45 and 500 mm subjected to compressive loads, through the comparison of analytical and finite element models using Abaqus® software. Analytical results show a critical force of 3481.1 N and 4017.5N for face sheet wrinkling and shear crimping, respectively. Numerical predictions for both phenomena present a maximum error of approximately 1%, showing that local buckling can be predicted independently of the slenderness ratio of the beam, as suggested by the analytical formulation. However, even for slender beams, the critical buckling load showed a coupling to local behaviour, reducing the corresponding eigenvalue. A maximum deviation of approximately 8% was obtained between analytical and numerical predictions. Finally, an experimental procedure was carried out to observe the associated buckling shapes. As indicated by analytical and numerical predictions, the specimen displayed a local buckling failure mechanism, however, at a much smaller load value related to geometric imperfections and asymmetric boundary conditions. Therefore, the study establishes a validation between analytical and numerical frameworks for predicting local instability failures in CFRP/PVC sandwich structures, providing a tool for engineers to the design of sandwich panels for enhanced structural performance and lightweight and safe components.

Enhancement of Optical Absorption and Bandgap Decrease of PVDF/Curcuma Longa Linn Composites: UV-Vis Technique

E.A. Falcão, T. S. Silva, E.S.S. Rodrigues, S.M. Martelli — Thu, 11 Dec 2025 00:00:00 +0000

In the present work, the polyvinylidene fluoride (PVDF) and PVDF/Curcuma longa Linn (PVDF/CLL) were prepared in five different concentrations. The FT-IR technique was used to analyze the incorporation of CLL in the PVDF matrix. The CLL introduction in the PVDF matrix increases de relative percentage of phase. The optical properties of PVDF/CLL were studied using UV-Vis spectroscopy. The incorporation of CLL into the PVDF matrix changes the optical absorption in the UV-Vis region and shifts the optical absorption edge to higher wavelengths. The optical transmittance of pure PVDF exceeds 70% from 270 nm to 1400 nm. The addition of 5% CLL reduces optical transmittance by 50%, and at concentrations above 20%, the reduction approaches 100%. The extinction coefficient of PVDF/CLL 10% presents two peaks, one at 234 nm and the other at 421 nm. However, higher concentrations of CLL change the first peak from 234 nm to 247 nm. The skin depth decreases with increasing photon energy. The CLL addition in the PVDF matrix shifts the indirect and direct optical bandgaps towards lower energies. The observed decrease in the bandgap is consistent with the optical absorption edge results. Finally, these results show that PVDF/CLL composites are potential candidates for optical and photonic applications.

Optimization of Shrinkage and Mechanical Properties in Continuous Glass Fiber-Reinforced Polypropylene Composite I-Beams during Pultrusion Process

Huihuang Ma, Zijian Wang, Yizhao Fu, Luo Luo, Xiaodong Zhou — Mon, 15 Dec 2025 00:00:00 +0000

This study addresses shrinkage marks in pultruded continuous glass fiber-reinforced polypropylene I-beams by modifying the cooling mold with compensation segments, adding nano-SiO₂ as a nucleating agent, and incorporating glass fiber mesh. Under optimized conditions (80 mm/min, 235°C, 65–85–105°C), a compensation segment of 85 mm length and 0.5 mm depth effectively reduced surface shrinkage. Adding 2 wt% nano-SiO₂ lowered vertical shrinkage from 3.07% to 1.15% and horizontal shrinkage from 1.57% to 0.23%. An 8-mesh glass fiber grid further improved dimensional stability while maintaining a bending failure load of 5132.26 N and yield load of 3090 N. These strategies collectively enhance dimensional accuracy and mechanical performance in thermoplastic composite I-beams.

Influence of Environment Aging on the Thermal Insulation of Sustainable Ecofriendly Composites

K. Ramanaiah, Hari Sankar Palla, Kunapuli Siva Satya Mohan — Fri, 19 Dec 2025 00:00:00 +0000

In recent years, researchers are increasingly emphasized the development of sustainable biodegradable composites to minimize environmental impact and broaden their potential in engineering fields. This study investigates the influence of environmental aging including, exposer to tap water, sea water and aqueous (NaOH) solutions, on the thermal insulation behavior of sansevieria /PLA-based biodegradable composites. The water uptake characteristics and diffusion coefficients were determined and analyzed to understand their effects on material performance. Results revealed a significant rise in thermal conductivity after moisture absorption, indicating a decline in insulation performance. the percentage increase in thermal conductivity of S4 in tap water, sea water and aqueous solution compared to dry state are 112.69, 156.03 and 189.36, respectively. The mechanisms responsible for the deterioration of thermal insulation due to water penetration are examined, providing insights in to the durability and environmental stability of these insulation materials.

Machine Learning-Driven Optimization of Biodegradable Polymer Nanocomposites for Improved FDM Printability and Strength

Fri, 26 Dec 2025 00:00:00 +0000

Biodegradable polymer nanocomposites have emerged as promising sustainable materials for additive manufacturing, especially in Fused Deposition Modeling (FDM). However, their printability and mechanical performance remain highly sensitive to formulation variability and process parameter interactions. Addressing these limitations requires a systematic and predictive approach that integrates materials engineering with advanced data-driven tools. The present work aims to develop a machine learning-driven optimization framework for enhancing the printability and strength of biodegradable polymer nanocomposites used in FDM. A series of PLA-based and PHA-modified nanocomposites reinforced with cellulose nanocrystals (CNC) and nanosilica (SiO₂) were fabricated using a design-of-experiments approach. Key extrusion and printing parameters—including nozzle temperature, bed temperature, infill density, raster angle, and feed rate—were systematically varied to generate a comprehensive experimental dataset. Supervised machine learning models (Random Forest, XGBoost, and Artificial Neural Networks) were trained to predict printability indices and mechanical responses, including tensile strength, layer adhesion, and dimensional accuracy. Among the models evaluated, XGBoost achieved the highest predictive accuracy with an R² of 0.96 for tensile strength and 0.94 for printability. Feature importance analysis revealed that nanofiller loading, nozzle temperature, and infill density were the most influential factors. The optimized formulation identified by the ML framework—PLA/PHA with 1.5 wt% CNC—combined with optimal FDM settings resulted in a 22.8% improvement in tensile strength and a 17.4% increase in printability index compared to baseline samples. These results demonstrate that machine learning offers a powerful pathway for designing next-generation biodegradable nanocomposites and advancing sustainable, high-performance FDM manufacturing.

Nickel Loaded into Three-Dimensional Porous Composite Materials Doped by Nitrogen Atoms for Accelerating the Conversion Process of Polysulfides

Mon, 29 Dec 2025 00:00:00 +0000

The industrial deployment of lithium–sulfur batteries remains hindered by sulfur’s intrinsically low electrical conductivity and the pronounced shuttle effect that arises during cycling. In this study, a novel porous composite material (GA/Ni-CN) was prepared by loading the nickel metal catalyst onto nitrogen-doped three-dimensional graphene aerogel carbon-based materials. Graphene aerogel and ZIF-derived nitrogen-doped carbon framework composites provide abundant polar sites while maintaining a stable three-dimensional porous structure, enhancing polysulfide adsorption. A small amount of metallic nickel phase serves as the electrocatalytic center, accelerating the redox conversion of polysulfides while preventing catalyst overconsumption. The battery assembled with S@GA/Ni-CN as the cathode material exhibits excellent electrochemical performance and shows high electrochemistry response in cyclic voltammetry testing. In addition, the initial discharge specific capacity got to 1482 mAh/g at 0.2 C current density, substantially surpassing the sulfur utilization efficiency of conventional carbon-based materials.

Facile Fabrication of Renewable Wood-Derived Carbon/SiBCN Aerogel Composites for High-Performance Microwave Absorption

Mon, 29 Dec 2025 00:00:00 +0000

With the rapid development of communication technologies, there is an urgent demand for high-performance microwave absorbing materials. Wood-derived carbon (WDC), characterized by its lightweight, renewable, low-cost, and tunable dielectric properties, is regarded as a core candidate for future green microwave absorbing materials. However, pure WDC exhibits relatively limited microwave absorption performance. Thus, this work demonstrates a facile strategy for integrating WDC with SiBCN aerogels via controlled growth within the WDC matrix, achieved through a two-step sol-gel process combined with thermal treatment. SiBCN aerogel particles formed a typical three-dimensional network structure within the pores of WDC. The resulting WDC/SiBCN aerogel composite achieved a minimum reflection loss (RL_min) of -46.0 dB at a thickness of only 1.71 mm, with an effective absorption bandwidth (EAB) of 3.60 GHz, which demonstrates significantly enhanced microwave absorption performance compared to existing similar systems. The performance improvement is attributed to the synergistic effects of dipole polarization, multiple reflection mechanisms, and excellent impedance matching between the SiBCN aerogel and wood-derived carbon. This research provides a novel strategy for fabricating WDC/SiBCN aerogel composites that combine renewability with superior microwave absorbing capabilities.

AI-Based Defect Identification in FDM-Printed Biodegradable Polymer Composites Through Multimodal Characterization

Mon, 29 Dec 2025 00:00:00 +0000

The growing demand for biodegradable polymer composites in sustainable manufacturing requires robust quality-assessment frameworks that ensure structural reliability and functional performance. However, FDM-based additive manufacturing of such materials often introduces processing-induced defects that compromise mechanical integrity. Conventional visual inspection remains subjective and limited, creating a need for advanced, automated defect-identification strategies. This study addresses this challenge by integrating artificial intelligence with multimodal characterization to establish a reliable defect-detection pipeline for FDM-printed biodegradable polymer composites. Biodegradable PLA-based composites reinforced with microscale and nanoscale fillers were fabricated under controlled FDM conditions, followed by systematic defect mapping through optical imaging, SEM, and surface profilometry. A convolutional neural-network classifier was trained using 2,500 labelled images, incorporating multimodal inputs to identify four major defects: voids, layer gaps, surface roughness irregularities, and under-extrusion patterns. The optimized AI model achieved an overall classification accuracy of 96.4%, precision of 94.8%, recall of 95.3%, and an F1-score of 95.0%, outperforming traditional threshold-based and handcrafted-feature methods. Multimodal correlation analysis further revealed that defects predicted with high probability aligned strongly with SEM-verified structural anomalies (R² = 0.93) and surface-roughness deviations (up to 18% variation). These results demonstrate that AI-assisted evaluation offers a reliable, scalable, and non-destructive pathway to improve defect quantification in biodegradable polymer composites. The proposed framework enhances process monitoring, reduces inspection subjectivity, and provides new insights into structure–processing–defect interrelationships in FDM-printed sustainable composites.

Mechanical and Microstructural Performances of One-Part Alkali-Activated Fly Ash Mortars with Thermally Activated Palm Oil Decanter Cake

Tue, 30 Dec 2025 00:00:00 +0000

The utilisation of waste-derived precursors in one-part alkali-activated materials offers a promising route towards more sustainable cementitious systems. This study evaluates calcined palm oil decanter cake (PODC) as a partial replacement for Class C fly ash in one-part alkali-activated mortars. PODC was thermally treated at 400 °C to reduce organic content while retaining biochar and incorporated at replacement levels of 5–20%. Fresh properties, physical characteristics, mechanical performance, and microstructural development were systematically assessed. Increasing PODC content reduced flowability and shortened setting time, attributed to the lower density, irregular particle morphology, and water-retention behaviour of biochar. Despite these changes, bulk density, water absorption, and apparent porosity were only marginally affected, indicating that matrix compactness was largely preserved. Strength development depended strongly on replacement level. Mortars with 10% and 15% PODC showed improved performance relative to the control, with 15% achieving the highest long-term compressive strength due to additional reactive Ca, K, and Si contributed by PODC. The 10% replacement provided a more balanced response, combining improved workability, stable early-age strength, and enhanced flexural and splitting tensile strengths. In contrast, 20% replacement led to strength reduction associated with increased porosity and a weaker interfacial transition zone. XRD, TG–DTA, and SEM–EDS confirmed substantial consumption of PODC phases and the formation of well-developed binding gels (C–S–H, C–A–S–H, and alkali-substituted (N,K)–A–S–H). Residual biochar acted as a preferential site for gel nucleation, promoting matrix cohesion. Overall, calcined PODC is an effective supplementary precursor for one-part fly ash-based alkaline-activated mortars, with an optimal replacement range of 10–15%.

Explainable AI for Structure–Property Analysis of FDM-Printed Biodegradable Polymer Nanocomposites

Tue, 30 Dec 2025 00:00:00 +0000

Biodegradable polymer nanocomposites have gained significant attention for sustainable engineering applications, particularly when processed through fused deposition modeling (FDM) to create complex, customizable structures. Despite their potential, understanding how processing conditions and nanoscale reinforcements collectively influence the final properties remains a persistent challenge. The primary difficulty arises from the nonlinear, multivariate nature of structure–property interactions in FDM-printed biodegradable systems, which conventional modeling approaches often fail to capture or interpret. This study aims to develop an explainable artificial intelligence (XAI) framework capable of predicting and interpreting the mechanical and thermal behavior of biodegradable polymer nanocomposites fabricated via FDM. Biodegradable polymer matrices reinforced with 0–5 wt% nanoscale fillers were printed under controlled variations of nozzle temperature, layer height, infill density, and raster orientation. Machine learning models—including random forest and gradient boosting regressors—were trained on experimentally obtained structural, morphological, and thermal descriptors, while SHAP-based explainability tools were used to identify dominant contributors to property variation. The proposed framework achieved high predictive accuracy for tensile strength (R² = 0.93, RMSE = 3.1 MPa) and elastic modulus (R² = 0.91, RMSE = 45 MPa), and reliably predicted thermal stability (R² = 0.89 for T₅%). Explainability analysis revealed that infill density, nanofiller dispersion quality, and crystallinity index contributed up to 78% of the variance in mechanical response, whereas extrusion temperature and filler–matrix interfacial compatibility dominated thermal behavior. These findings provide mechanistic insights into the structure–property relationships governing FDM-printed biodegradable nanocomposites and demonstrate the potential of XAI to guide systematic material design and process optimization.