A comparative analysis was performed on poly(lactic acid) (PLA), poly(caprolactone) (PCL), basalt fiber (BF) composites produced using two distinct approaches: direct blending and masterbatching. The limitations of PLA-BF composites with regard to distribution and adhesion are well-documented, as are chemical treatment methods (addition of compatibilisers, surface treatments, silanization). This work aimed to study an industrially relevant potential solution of utilising a PCL-BF masterbatch, prepared as a 50/50 wt.% blend using planetary roller extrusion (PEX) to both improve the distribution and homogeneity of the fibers as well as provide a secondary adhesion site to facilitate improved mechanical properties of the final PLA-PCL-BF composite. The resultant materials were injection moulded to prepare ISO standard test specimens and tested on the basis of their physical properties via tensile testing, impact strength testing, flexural analysis, Fourier transform infrared spectroscopy and water absorption capability. The results displayed that the incorporation of PCL and BF led to an increase in ductility of the composite materials, allowing for improvements in the inherent brittleness of virgin PLA. Major increases in the impact strength were achieved with the utilisation of a 25% PCL/BF masterbatch, allowing for a greater than 50% increase. As an overall observation, the use of a masterbatching process, opposed to direct blending of the constituent materials allows for a greater consistency of composite to be achieved at the expense of increased gains.

Maleic anhydride (MAH) grafting is widely employed to compatibilise polylactic acid (PLA) in fibre-reinforced composites; however, the influence of reactant addition sequence during melt processing varies widely across the literature, with no clear consensus on an optimal approach. In this study, the effect of reactant addition sequence on the graft yield of MAH onto PLA was investigated using dicumyl peroxide (DCP) as an initiator. Four loading protocols were examined in which the order of addition of PLA, DCP, and MAH was varied using approaches commonly reported in the literature, while all other processing conditions were held constant. A strong dependence of grafting yield on addition sequence was observed, with values ranging from 0.12% to 0.51%, corresponding to more than a four-fold variation under otherwise identical processing conditions. Simultaneous addition of PLA, DCP, and MAH produced the highest grafting yield, attributed to a more effective utilisation of peroxide-derived radicals. These results demonstrate that the reactant addition sequence is a critical processing variable governing MAH grafting efficiency and that simultaneous addition represents the most effective processing strategy under the conditions examined.

This study investigates the influence of nanosilica (NS) and nanoclay (NC) additives on the Mode-I interlaminar fracture toughness (GIC) and interlaminar shear strength (ILSS) of intraply woven carbon/Kevlar fiber reinforced epoxy (CKFRE) composites. The toughening mechanisms were observed using a scanning electron microscope and an optical microscope. Results show that both nanoparticle type and concentration critically affect interlaminar performance. At optimum loadings, CKFRE/NC composites exhibited up to 19.1% (2 wt%) and 17.2% (4 wt%) increases in GIC, while CKFRE/NS achieved a 48.4% improvement at 0.5 wt%. ILSS performance followed a similar trend, with enhancements of 21.6% (2 wt% NC) and 25.7% (0.5 wt% NS). These improvements were attributed to synergistic toughening mechanisms, including crack deflection, particle-induced crack pinning, fiber bridging, and enhanced fiber-matrix stress transfer. However, higher nanoparticle concentrations led to agglomeration, resin-rich zones, and a reduction in interfacial bonding efficiency, resulting in deterioration of the properties. The findings highlight optimal concentration ranges of 2-4 wt% NC and 0.5-1 wt% NS, providing valuable design guidelines for next-generation hybrid composites with improved interlaminar properties for aerospace, defense, and automotive applications.

With the recent introduction of the European Union's Packaging and Packaging Waste Regulation (PPWR) in February 2025, reusable plastic packaging schemes have gained increasing attention as a more circular and sustainable alternative to single-use plastics (SUPs). However, a major barrier to the widescale adoption of these schemes lies in ensuring effective sanitization and disinfection after each reuse cycle. The risk of cross-contamination between use cycles presents the hazard of foodborne illness, which could undermine consumer trust and result in nonengagement with such systems. Antimicrobial surfaces represent a promising solution for enhancing the microbial safety and improving the cleanability of reusable packaging. These surfaces are designed to inhibit the growth and survival of microorganisms such as bacteria, viruses, and fungi that contribute to food spoilage and foodborne illness. Their integration into packaging systems could potentially improve consumer confidence and accelerate adoption by facilitating easier sanitization and reducing the risk of microbial cross-contamination. A range of strategies exists for fabricating antimicrobial surfaces, broadly categorized into chemical and physical approaches, each with distinct advantages and limitations in the context of food packaging. This review critically examines the functionality of these surface types and evaluates their potential for reusable food packaging applications.

The excellent processability and strong environmental sustainability contribute to the increasing use of basalt-based composites in various construction industries. This study examines the interlaminar shear strength (ILSS) of sustainable basalt fibre-reinforced polymer composites (BFRP), with a focus on the performance of a thermoplastic Elium-based matrix and a conventional thermoset epoxy matrix. Basalt fibres were surface-modified with dopamine (Do) and dopamine-graphene nanoplatelet (Do-GNP) coatings to enhance fibre/matrix interaction. Melamine was used to functionalise GNP to enhance dispersion within the DO. Coating Bf with Do and Do-GNP improved the ILSS values, even after normalising the results. Short beam shear (SBS) testing showed that the BF/Elium composite reached a maximum load 83

Reusable packaging offers a promising route to reduce the environmental impact of single-use plastic, but its safety depends on effective sanitisation and control of bioburden across multiple use cycles. Micro- and nanoscale surface textures provide a non-chemical strategy to enhance liquid repellency and potentially reduce bioburden and microbial accumulation by tailoring surface topography and wettability. In this study, we injection moulded three surface textures ranging from the micro- to nanoscale on polypropylene (PP) and polybutylene terephthalate (PBT) using laser-modified steel tooling inserts. We evaluated their mouldability, wetting behaviour, antimicrobial performance, and durability under repeated washing. The patterns were successfully replicated on PP and partially on PBT, highlighting material-dependent challenges when moulding features at this scale. All textures increased surface hydrophobicity, with water contact angles values of > 120 degrees and > 110 degrees recorded for PP and PBT, respectively. However, surface textures did not reduce bacterial attachment or viability. Importantly, repeated washing altered surface roughness, chemistry and wettability but did not compromise microbial safety or increase bioburden. These findings advance our understanding of how engineered surface textures influence hydrophobicity and bioburden/microbial accumulation in reuse-relevant conditions, informing the design of textured polymer surfaces for applications where hygiene and material longevity are critical.

This research paper employed the recently developed Elium thermoplastic resin and basalt fabrics as an alternative to thermoset/synthetic fibre composites to reduce their environmental impact. Elium® 191 XO/SA and Epoxy PrimeTM 37 resin were reinforced with mineral-based semi-unidirectional basalt fibre (BF). Physical, chemical, tensile, and flexural performance was investigated under the effect of hydrothermal seawater ageing at 45 °C for 45 and 90 days. The results show that the BF/Elium composite exhibited superior tensile and flexural strength, as well as good stiffness, compared with the BF/Epoxy composite. Digital images and scanning electron microscope images were used to describe the fracture and failure mechanisms. The tensile and flexural strength values of the BF/Elium composite were 1165 MPa and 1128 MPa, greater than those of the BF/Epoxy composite by 33% and 71%, respectively. The tensile and flexural modulus values of the BF/Elium composite were 44.1 GPa and 38.2 GPa, which are 30% and 12% greater than those of the BF/Epoxy composite. The result values for both composites were normalised with respect to the density of each composite laminate. Both composites exhibited signs of resin decomposition and fibre surface degradation under the influence of seawater ageing, resulting in a more recognisable reduction in flexural properties than in tensile properties.

This study provides a comprehensive investigation of antimicrobial additives (ZnO/AgNPs and SiO2/AgNPs) on the properties of biodegradable ternary blends composed of poly(hydroxybutyrate) (PHB), poly(lactic acid) (PLA), and polycaprolactone (PCL) by examining the morphology, thermal stability, crystallinity index, and cell viability of these blends. Overall, transmission electron microscopy (TEM) analysis revealed that AgNPs and SiO2 exhibited comparable sizes, whereas ZnO was significantly larger, which influences their release profiles and interactions with the blends. The addition of antimicrobials influences the rheology of the blends, acting as compatibilizers by reducing the intermolecular forces between biopolymers. Scanning electron microscopy (SEM) analysis revealed a matrix-core-shell structure, indicating enhanced interfacial interaction among the immiscible biopolymers, as predicted by their spreading coefficient. From thermal evaluations, PCL promotes overall thermal stability, where T5 (the temperature at which the sample loses 5% of its weight through thermal degradation) was more than 22% higher than T5 of blends, and the antimicrobials investigated tend to act as barriers to heat penetration, thereby influencing the degradation mechanism of the blends. Additionally, antimicrobials tend to increase material crystallinity, suggesting their nucleating effect. Both PLA and PCL have shown high viability for cell growth and proliferation. The 30/50/20 (PHB/PLA/PCL wt%) blends were conducive to cell adhesion and proliferation, achieving cell viability rates up to 85% irrespective of the antimicrobial concentration. SEM analysis also confirmed the presence of viable cells and attachment of organic cell structures over the surface of the produced materials. In conclusion, this study highlights the potential of biodegradable ternary blends containing antimicrobial NPs, particularly for use in medical devices such as ureteral stents.

Polyetherketoneketone (PEKK) is a promising material for additive manufacturing due to its exceptional properties, making it a primary candidate for in-space manufacturing. Fused filament fabrication is a leading additive manufacturing technology for in-space manufacturing, offering advantages in terms of the manufacture of complex geometries and zero waste production. However, post-process annealing is necessary to alleviate residual stresses and optimize PEKK's mechanical performance. This study investigates the effects of annealing on the mechanical, physical, and thermal properties of two grades of PEKK, namely PEKK-A and PEKK-SC, which are amorphous and semi-crystalline, respectively. The study examines the impact of annealing temperatures on the crystallinity and mechanical performance of the materials. Experimental results indicate that annealing at 260 degrees C significantly enhances the tensile and flexural properties of both PEKK-A and PEKK-SC, with a parallel increase in crystallinity. X-ray diffraction analysis reveals a phase transformation in crystal structures, with the predominance of form one crystals following annealing. Differential scanning calorimetry results further support the increase in crystallinity and molecular order, leading to improved mechanical properties. This research provides valuable insights into optimizing post-processing parameters to enhance the performance of PEKK in additive manufacturing applications.

High‐performance polymers (HPP) have gained significant attention in recent years because of their potential for metal replacement in industries with demanding environments, such as aerospace, where high‐strength lightweight parts are essential. A critical area of research for HPPs is additive manufacturing (AM). Polyetherketoneketone (PEKK) and polyetheretherketone (PEEK) stand at the forefront of this research owing to their excellent mechanical, chemical, and physical properties while making them ideally suited for metal replacement applications in aerospace. Fused filament fabrication (FFF) is a key processing methodology in AM, offering a promising approach to manufacturing PEKK and PEEK. This review explores the process‐structure–property relationships of PEEK and PEKK manufactured using FFF, focusing on the impact of processing parameters on the material's mechanical properties. Although PEEK has been extensively studied, a significant gap exists in the literature concerning PEKK's behavior under similar circumstances. This review highlights the need for further investigation into the FFF processing of PEKK and its effects on PEKK's unique chemical structure.

This study explores the mechanical performance of polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) filaments fabricated using fused filament fabrication (FFF), Arburg plastic freeforming (APF), and injection moulding (IM). A series of controlled experiments, including differential scanning calorimetry (DSC), scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMA), and mechanical tests, were conducted to evaluate the material’s mechanical, thermal, and chemical properties. The results highlight the influence of process parameters and material choice on the mechanical properties of PC/ABS components. The FFF samples exhibited the highest impact strength (up to 28.82 kJ/m²), attributed to porosity acting as a stress absorber under impact load. However, this same porosity led to a 9.14% and 19.27% reduction in flexural and tensile strength, respectively, compared to the APF samples, where stress concentration effects were more pronounced under flexural loads. APF’s mechanical properties were comparable to those of IM, with the process achieving the highest tensile strength, highlighting its potential for producing robust PC/ABS samples. This study aims to provide valuable insight into the selection of additive manufacturing (AM) processes for PC/ABS components.

Digital twin (DT) technology has become a cornerstone in the simulation and analysis of real-world systems, offering unparalleled insights into the lifecycle management of physical assets. By providing a real-time synchronized replica of the physical entity, DTs enable predictive maintenance, performance optimization, and lifecycle extension, which are pivotal for industries aiming for digital transformation. This paper presents a comprehensive comparative study of DT development of a robotic arm using two prominent simulation platforms: Unity and Gazebo. Unity, with its roots in the gaming industry, offers robust real-time rendering and a user-friendly interface, making it a versatile choice for various industries. Gazebo, traditionally used in robotics, provides detailed physics simulations and sensor data emulation, which is ideal for precise engineering applications. We explored the performance of both platforms in creating accurate and dynamic digital replicas. Through qualitative and quantitative analyses, this study evaluates each platform’s strengths and limitations. The study assesses these platforms across key performance metrics such as accuracy, latency, graphic quality, and integration with the Robot Operating System (ROS). The DTs were developed using a consistent physical setup and communication layer to ensure fair comparisons. The results indicate that Unity performed better in terms of accurately mimicking the robotic arm with lower latency, making it ideal for applications requiring high-fidelity visualizations and real-time responsiveness. However, Gazebo excels in its ease of ROS integration and cost-effectiveness, making it a suitable choice for smaller robotics and automation projects. This study conducts an empirical comparison of these platforms in terms of their performance in creating DTs of robotic arms which is not readily available. This paper aims to guide developers and organizations in selecting the appropriate platform for their DT initiatives, ensuring efficient resource utilization and optimal outcomes.

Fused filament fabrication (FFF), a leading additive manufacturing (AM) methodology has revolutionised the production of 3D objects. FFF enables the manufacture of complex geometries not achievable with traditional manufacturing methods. This study investigates the use of the high-performance polymer, polyetherketoneketone (PEKK) for advanced AM applications in the growing field of in-space manufacturing (ISM), where lightweight recyclable metal alternatives can greatly reduce launch payloads. Utilising a response surface methodology, this research examines the effects of print speed, layer thickness, nozzle temperature, and build platform temperature on PEKK's mechanical, physical, and thermal properties. Optimum print conditions for maximising the flexural modulus were identified as 30 mm/s print speed, 0.1 mm layer thickness, 380 degrees C nozzle temperature, and 140 degrees C build platform temperature. These parameters improve the material's crystallinity by extending its residence time in the printer's heated chamber. This prolonged exposure facilitates better molecular alignment and reduces thermal gradients, leading to a 30 % enhancement in crystallinity compared to conditions with higher print speeds and greater layer thicknesses. Scanning Electron Microscopy (SEM) and micro- computed tomography(mu CT) analyses revealed that layer thickness significantly influences void formation, with thinner layers yielding superior interlayer bonding and reduced void volume. Differential Scanning Calorimetry (DSC) confirmed that increased crystallisation had a direct impact on flexural modulus, increasing it to 3682 MPa, approaching 80 % of PEKKs injection moulding performance. This study highlights the complex relationships between the FFF parameters and PEKK's mechanical properties, highlighting its potential for industrial and ISM applications.

Leading-edge erosion (LEE) of wind-turbine blades, driven primarily by rain erosion, particulate erosion, and environmental ageing, remains one of the most pervasive causes of performance loss and maintenance cost in offshore and onshore wind farms. Self-healing coatings, which autonomously or semi-autonomously restore barriers and mechanical function after damage, promise a paradigm shift in blade protection by combining immediate impact resistance with in-service reparability. This review surveys the state of the art in self-healing coating technologies (intrinsic chemistries such as non-covalent interactions or dynamic covalent bonds; extrinsic systems including micro/nanocapsules and microvascular networks) and evaluates their suitability for anti-erosion, mechanical robustness, and multifunctional protection of leading edges. The outcomes of theoretical, experimental, modelling and field-oriented studies on the leading-edge protection and coating characterisation identify which self-healing concepts best meet the simultaneous requirements of toughness, adhesion, surface finish, and long-term durability of wind blade applications. Key gaps are highlighted, notably trade-offs between healing efficiency and mechanical toughness, challenges in large-area and sprayable application methods, and the need for standardised characterisation and testing of self-healing coating protocols. We propose a roadmap for targeted materials research, accelerated testing, and field trials. This review discusses recent studies to guide materials scientists and renewable-energy engineers toward promising routes to deployable, multifunctional, self-healing anti-erosion coatings, especially for wind-energy infrastructure.

A fabric orientation angle has a significant influence on the failure mechanisms at the lamina level. Any change in this angle can lead to a sudden reduction in strength, potentially resulting in catastrophic failures due to variations in load-carrying capacity. This study examined the impact of off-axis fabric orientation angles (0°, 15°, 30°, 45°, 60°, and 90°) on the flexural properties of non-crimp basalt-fibre-reinforced acrylic thermoplastic composites. The basalt/Elium® composite panels were manufactured using a vacuum-assisted resin transfer moulding technique. The results show that the on-axis (0°) composite specimens exhibited linear stress–strain behaviour and quasi-brittle failure characterised by fibre dominance, achieving superior strength and failure strain values of 1128 MPa and 3.85%, respectively. In contrast, the off-axis specimens exhibited highly nonlinear ductile behaviour. They failed at lower load values due to matrix dominance, with strength and failure strain values of 144 MPa and 6.0%, respectively, observed at a fabric orientation angle of 45°. The in-plane shear stress associated with off-axis angles influenced the flexural properties. Additionally, the degree of deformation and the fracture mechanisms were analysed.

Repairing large bone defects remains a significant clinical challenge due to the limitations of current treatments, including infection risk, donor site morbidity, and insufficient vascularization. The autograft is still the gold standard for large bone defects. In this study, we developed chitosan-based (CS-based) scaffolds, incorporating with hydroxyapatite (HAp) and fluorapatite (FAp) ceramics, fabricated by UV crosslinking and freeze-drying, and loaded with P28 peptide, alone or in combination with vascular endothelial growth factor (VEGF), to evaluate the effect of dual bioactive factor delivery. We hypothesized that CS-based scaffolds would optimize ceramic composition and co-delivery of P28 and VEGF, and can enhance early-stage osteogenic differentiation and support bone regeneration. The CS-based scaffolds were characterized by their physicochemical properties, including swelling behavior, mechanical strength, porosity, and in vitro degradation. Biological evaluations were performed including cell proliferation assays, ALP activity, ARS staining, and RT-qPCR, to assess osteogenic differentiation. The results showed that the scaffolds had high porosity, excellent swelling behavior, and degraded within 8 weeks. Dual delivery of P28 and VEGF significantly enhanced early osteogenic markers, indicating a complementary effect. These findings demonstrated that CS-based scaffolds with an optimized ceramic ratio and bioactive factor incorporation have the potential to facilitate bone regeneration.

Reusable packaging offers a promising solution to reducing plastic waste and promoting the sustainable and cleaner use of plastic materials. However, most plastic packaging is designed for single use and may lack the durability required to withstand repeated use under demanding conditions. In this study, we evaluate the performance of different polymer materials under repeated use conditions, focusing on changes in their appearance, material properties, and food contact safety. The investigated materials include the commodity polymers polypropylene (PP) and semi-crystalline polyethylene terephthalate (CPET), as well as the technical materials polybutylene terephthalate (PBT) and Tritan™ copolyester. Each material was subjected to simulated real-world conditions, including contamination with food, exposure to microwave heating or long-term cold storage, and repeated cleaning cycles. This methodology replicates the wear and tear experienced in everyday reuse scenarios. The results demonstrate that all tested materials maintained their dimensions, mechanical performance, and chemical migration. However, notable changes in visual quality and wettability were observed, which should be carefully considered for specific applications. Overall, this study provides valuable insights into the suitability of plastic materials for reusable food packaging, supporting the development of more sustainable products that align with cleaner production principles, and informing future reusable food packaging regulations.

Injection moulding (IM) is a precise manufacturing process capable of producing tight-tolerance, functional plastic components with high-quality surface finishes. However, the growing use of stereolithography (SLA) 3D printing for rapid, low-cost mould fabrication presents a challenge, as the layer-by-layer process produces a stair-step geometry that promotes a keying effect, leading to reduced surface quality, premature tool wear and poor part release during moulding. The study addresses the problem by examining the influence of print orientation on the stair-step effect on SLA-printed tooling by assessing how post-processing (bead blasting, polishing) and CAD-applied textures can improve surface integrity and tool longevity. A short production trial using polypropylene (PP) coupons measured surface roughness, contact angle and tool degradation. Post-processed and CAD-textured moulds effectively masked the stair-step effect and improved lifespan, achieving Ra values consistent with IM standards (0.2-2.5 mu m). In contrast, untreated moulds exhibited progressive wear and chipping before 20 cycles. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy confirmed mould material transfer causing surface contamination, while CT scans revealed warpage and dimensional variation of up to 13% due to print orientation. These findings demonstrate that targeted surface modification strategies significantly enhance the performance of SLA-printed moulds, providing a viable solution for short-run IM applications.

This research paper employed novel sustainable alternative materials to reduce the environmental impact of thermoset/synthetic fibre composites. The effect of seawater hydrothermal ageing at 45 °C for 45 and 90 days on the physical and interlaminar fracture toughness (mode I and mode II) of a semi-unidirectional non-crimp basalt fibre (BF)-reinforced acrylic matrix and epoxy matrix composites was investigated. Optical and scanning electron microscopes were used to describe the fracture and interfacial failure mechanisms. The results show that the BF/Elium composite exhibited higher fracture toughness properties compared to the BF/Epoxy composite. The results of the mode I and mode II interlaminar fracture toughness values for the BF/Elium composite were 1280 J/m2 and 2100 J/m2, which are 14% and 56% higher, respectively, than those of the BF/Epoxy composite. The result values for both composites were normalised with respect to the density of each composite laminate. The saturated moisture content and diffusion coefficient values of seawater-aged samples at 45 °C and room temperature for the BF/Elium and BF/Epoxy composites were analysed. Both composites exhibited signs of polymer matrix decomposition and fibre surface degradation under the influence of seawater hydrothermal ageing, resulting in a reduction in the mode II interlaminar fracture toughness values. Enhancement was observed in mode I fracture toughness under hydrothermal ageing, particularly for the BF/Epoxy composite, due to matrix plasticisation and fibre bridging.

The photopolymerisation-based 3D printing technique is widely used as a novel route for developing photosensitive resins for biomedical applications by incorporating nanoparticles. However, commercial resins are still limited with the high demand in the global market especially in medical devices, dentistry and tissue engineering. In this experimental research, functionalised graphene nanoplatelets (mGNP) are used as modifiers for a commercial photocurable resin to investigate chemical, thermal, mechanical, shape memory, antimicrobial and cytotoxicity characteristics. Flexural and hardness tests were used to study the mechanical properties. The fracture surface of the failed flexural sample was observed by scanning electron microscopy (SEM). The shape memory (SM) behaviour in terms of shape fixity and shape recovery was obtained using dynamic mechanical analysis (DMA). Contact angle goniometry is used to evaluate its hydrophilicity. The ISO 22196 standard method was conducted to evaluate the antibacterial activity of the 3D-printed nanocomposite surfaces. Results showed enhancement in the flexural, hardness, thermal conductivity, shape memory and antimicrobial behaviour for the nanocomposites modified with mGNP by 0.03, 0.06 and 0.1 wt%. In terms of antimicrobial efficacy, the nanocomposite with 0.1 wt% showed a significant reduction in bacterial count for both E. coli (Escherichia coil) and S. aureus (Staphylococcus aureus). The cell viability of all samples remained above 80% indicating the samples were non-toxic, which has the potential to be used for biomedical applications.