Search Results (344)

Alternating glycopolymers bearing periodically arranged pendant carbohydrate residues were synthesized by reversible addition–fragmentation chain transfer (RAFT) copolymerization of maltose-containing vinyl ether (MalVE) and ethyl maleimide (EtMI). The resulting trithiocarbonate-terminated polymers were subsequently converted into thiol-terminated glycopolymers through post-polymerization end-group transformation. These structurally well-defined alternating glycopolymers were immobilized onto gold nanoparticles (AuNPs) via Au–S interactions to construct glycopolymer-functionalized glycointerfaces. Surface functionalization of the AuNPs was confirmed by an increase in hydrodynamic diameter from approximately 42 to 59 nm after polymer immobilization. The resulting glycopolymer-functionalized AuNPs exhibited concentration-dependent lectin-mediated aggregation behavior in the presence of concanavalin A, accompanied by characteristic red shifts and broadening of the localized surface plasmon resonance (LSPR) band arising from multivalent carbohydrate–lectin interactions at the nanoparticle interface. Although the apparent association constants obtained for free alternating glycopolymers using fluorescently labeled lectin cannot be directly compared with those obtained from LSPR-based aggregation assays of AuNP-immobilized glycopolymers, the values increased from the order of 10⁵ L mol⁻¹ in solution to the order of 10⁷ L mol⁻¹ at the nanoparticle interface. This trend suggests that immobilization onto AuNPs enhances multivalent carbohydrate–lectin interactions through multivalent presentation of the glycopolymer chains at the nanoparticle interface. As a control experiment, peanut agglutinin (PNA), which does not recognize maltose residues, was added to the glycopolymer-functionalized AuNPs. No significant LSPR shift or spectral broadening was observed, indicating that nanoparticle aggregation was not induced by nonspecific lectin addition but arose from specific interactions between maltose residues and Con A. Quantitative analysis suggested that polymer chain length may influence the aggregation behavior. These results demonstrate that alternating glycopolymers provide a useful platform for constructing sequence-regulated glycointerfaces and for investigating multivalent biomolecular interactions at nanoparticle surfaces. Full article

Flexible strain sensors have attracted considerable attention in gait recognition owing to their ability to adhere directly to the skin near joints and transduce local deformation. In existing work, however, sensor placement and orientation are largely determined by anatomical experience, while multi-channel classification still relies on back-end digital processors, whose power consumption and latency constrain system practicality in wearable scenarios. This paper presents an integrated design path that proceeds from skin-mechanics theory through sensor-layout optimization to analog-domain front-end inference. On the layout side, the lines-of-non-extension (LoNE) theory is employed to convert the selection of sensor attachment angles from empirical judgment into a calculable mechanics problem; guided by the spatial course of LoNE in the ankle and knee regions, the positions and angles of the nine sensors are determined individually—channels perpendicular to the LoNE capture maximum strain, channels offset by 45 degrees supplement non-sagittal-plane information, and a channel aligned along the LoNE provides a near-zero-strain reference. On the circuit side, the mathematical equivalence between the weighted summation of a linear classifier and Kirchhoff’s current law (KCL) nodal current superposition is exploited to map the classification operation onto current aggregation in an analog circuit, yielding an in-sensor computing (ISC) front end in which the nine-channel weighted summation is completed in a single analog step. The sensors are fabricated by screen-printing a liquid-metal–polymer composite conductive ink onto a TPU film substrate, with a gauge factor RSD of $6.8\%$ and a tensile linearity $R^2>0.99$. Using walking, running, and stair descent as verification targets, the analog classifier reaches 99% accuracy at the circuit-level functional-verification stage. On real multi-subject data, it achieves $87.0\%\pm 8.4\%$ accuracy under intra-subject cross-session validation, with an analog-domain inference response faster than $100\mathsf{\mu }\mathrm{s}$. This design path is not bound to a specific joint or sensor material; when the layout methodology is extended to additional joint regions and the circuit architecture incorporates multiple outputs to cover more classification categories, the same workflow remains applicable, offering a promising low-power, lightweight technical solution for wearable motion monitoring. Full article

Due to the environmental concerns associated with petroleum-based plastics, industry and academia have directed increasing attention toward marine-derived biodegradable biopolymers, particularly those obtained from seaweed. In line with global efforts to enhance resource efficiency and sustainability by introducing non-fossil raw materials into the circular economy, seaweed valorization has emerged as a promising pathway. Seaweeds are attractive feedstocks due to their biodegradability, non-toxicity, antioxidant activity, and excellent film-forming capacity. This review provides a critical and application-oriented overview of seaweed biomass for food packaging applications by comparatively discussing the relationship between seaweed composition, extraction technologies, material functionality, packaging performance, and regulatory considerations. Emphasis is placed on the role of structural biopolymers and bioactive compounds in the development of passive, active, and intelligent packaging systems. Recent advances in extraction technologies, polymer modification strategies, and incorporation of functional additives are critically discussed in relation to their influence on the physicochemical, mechanical, barrier, antioxidant, and antimicrobial properties of seaweed-based composites. Furthermore, the review highlights key challenges limiting industrial implementation, including high hydrophilicity, high variability between the batches, energy-intensive drying processes, regulatory compliance, migration safety, and long-term material stability. Overall, seaweed-derived materials demonstrate strong potential as sustainable alternatives to conventional packaging systems, particularly in food applications. However, further optimization of processing technologies, material standardization, techno-economic feasibility, and end-of-life management are still required before large-scale commercialization can be achieved. Full article

The exponential growth of the global textile industry, largely driven by the demand for synthetic polymers such as poly(ethylene terephthalate) (PET), polyamides, and polyurethanes, has led to severe environmental consequences, notably the accumulation of persistent microplastics and solid waste. While conventional mechanical and chemical recycling methods are widely employed, they are often hindered by harsh processing conditions and the deterioration of material properties. Consequently, there is a critical need for sustainable end-of-life management strategies. This review provides a comprehensive analysis of the biodegradability of synthetic textile fibres, with a primary focus on emerging biotechnological and enzymatic recycling approaches. It systematically examines the intrinsic polymer characteristics that govern biodegradation—including molecular orientation, crystallinity, functional groups, and fibre chemistry—as well as extrinsic factors such as textile finishings, yarn twist, polymer blends, and chemical additives. Furthermore, the current landscape of microbial and enzymatic degradation routes is critically assessed, highlighting the specific mechanisms of biocatalysts (e.g., lipases, cutinases, PETase, and MHETase) in depolymerising complex synthetic matrices into recoverable monomers. Finally, this review identifies the existing literature gap between bulk plastic and textile-specific biodegradation, discussing future perspectives. By bridging polymer science and textile engineering, this work underscores the potential of enzymatic recycling to close the loop in synthetic fibre production and advance the transition toward a circular economy. Full article

Magnesium hydroxide is attracting growing interest as a versatile, halogen-free flame retardant, and this review surveys its production routes, structure–property relationships and use in polymer systems from commodity polyolefins to advanced bio-based materials. Industrial Mg(OH)₂ is still predominantly obtained from mining or hydration of MgO, but increasing attention is being devoted to recovery from seawater and saltwork brines, where precipitation from Mg²⁺-rich streams followed by controlled rehydration or direct precipitation yields fine, high-purity powders suitable for flame retardant use and simultaneously valorizes saline wastes. In parallel, hydrothermal synthesis has been extensively explored to tailor particle size and morphology by adjusting the precursor, solvent, temperature and time, enabling high-surface-area Mg(OH)₂ or MgO with narrow size distributions that are attractive for high-performance composites also evaluated via ball milling, crushing and refining. More recently, process intensification strategies such as microwaves and ultrasounds have been proposed to shorten reaction times, lower temperatures and better control nucleation and growth, opening paths toward energy efficient production of structured Mg(OH)₂ from both conventional and brine-derived precursors. The second part of the review analyzes how the intrinsic endothermic decomposition and basic character of Mg(OH)₂ can be utilized across a broad range of polymer matrices and how surface functionalization strategies extend its applicability. In addition to “as received” powders, stearic acid and other fatty acids, metal soaps and various organic coupling agents are widely used to render the surface more hydrophobic, enhance dispersion and interfacial adhesion, and in some cases introduce additional char-forming or barrier functionality. In terms of the application, the review methodically synthesizes and contrasts fire and mechanical data for Mg(OH)₂-containing polyolefins (HDPE, LLDPE, PP and EVA) utilized in cables and building products, expandable polymers and foams, biopolymers (PLA and PBS), and elastomers. The review places particular emphasis on the balance between loading level, processability, flame performance and mechanical integrity. This review aims to provide a comprehensive framework for designing next-generation Mg(OH)₂-based flame-retardant systems for both conventional and emerging polymer technologies. To this end, it integrates advances in sustainable feedstocks, controlled synthesis and surface engineering with the rapidly expanding application space. Full article

The linear economic model continues to drive multidimensional environmental problems, as it generates large volumes of plastic waste, as well as agricultural by-products, such as coconut husks. On the other hand, the maritime industry still relies on conventional materials such as wood, steel, and fibre-reinforced plastics, which have several usage challenges, including corrosion, toxicity, and difficulties associated with end-of-life management. These issues point to the need for more sustainable material options. This review examines the potential of combining coconut fibre (coir) with recycled plastics to produce a functional material for use in the maritime sector. The material is designed to add value to waste streams by providing a practical approach to reducing dependence on conventional and less sustainable resources. The review discusses fibre treatments (alkali, silane, acetylation) and fabrication methods (compression moulding, extrusion) and evaluates their impact on mechanical performance and durability. The studies show that coir–plastic composites possess highly tuneable mechanical properties. Tensile strengths are reported to range from approximately 2.4 MPa for natural resin matrices to 78 MPa for polyester hybrids, while the flexural modulus can be increased by up to 99% compared to the neat polymer blend. Fibre treatments (e.g., alkali) and fabrication methods are crucial, as they have been shown to improve tensile and flexural strength by over 40% and impact strength by 150%. However, the composites produced still show vulnerability to water absorption, UV radiation, and biofouling, which could limit their application in marine environments. To this end, several issues require further study, including long-term field validation, enhanced understanding of material fatigue, and scalable manufacturing. Full article

Achieving a circular and climate-neutral bioeconomy by 2050 requires not only high-quality recycling but also the large-scale integration of renewable carbon from biomass and atmospheric CO₂ into material systems. Plastics represent the world’s largest and most rapidly growing carbon sink, positioning them as a critical intervention point for replacing fossil-based feedstocks with renewable alternatives. Because plastic packaging is one of the most visible material streams encountered by consumers in daily life, a transition toward sustainable, recyclable bioplastics has the potential to deliver both meaningful environmental benefits and strong societal impact, accelerating public awareness and acceptance of renewable carbon solutions. Poly(ethylene furanoate) (PEF)—a fully bio-based polyester synthesized from plant-derived 2,5-furandicarboxylic acid (FDCA) and monoethylene glycol (MEG)—offers a promising pathway toward more sustainable packaging due to its superior mechanical strength and gas-barrier performance relative to polyethylene terephthalate (PET). This study presents a cradle to grave life cycle assessment (LCA) of PEF resin production and PEF bottle applications, using industrially relevant, at-scale process data covering biomass feedstock conversion, polymer synthesis, packaging manufacture, use phase, and end of life. Bottle applications were selected as a focal point due to their technical maturity, commercial relevance, and suitability for direct comparison with incumbent PET systems. The results indicate that PEF can reduce greenhouse gas emissions by up to 71% and fossil resource depletion by 26% compared to PET at the resin level when biogenic carbon uptake is included. Moreover, the material’s enhanced functional properties enable lightweight, recyclable bottle designs with carbon footprint reductions of up to 88% for 500 mL formats under a baseline recycling rate scenario of 72%, with the remaining share directed to municipal solid-waste incineration with energy recovery. Sensitivity analyses reveal that virgin PEF maintains environmental advantages over PET even when PET incorporates high levels of recycled content, highlighting the complementary roles of renewable carbon and circular material strategies. Prospective scenario modeling underscores the importance of sustainable feedstock selection and process electrification, with sucrose-based routes offering the largest potential for further decarbonization. Overall, the findings demonstrate that PEF is a scalable biopolymer capable of delivering substantial climate benefits while supporting circularity objectives. By targeting a highly visible consumer application—plastic packaging—this transition amplifies the societal impact of adopting renewable carbon materials. The study provides actionable insights for policymakers, industry stakeholders, and sustainability practitioners working to advance a more resilient, renewable, and consumer-recognizable plastics economy. Full article

Life Cycle Assessment (LCA) is extensively employed to support sustainability evaluation in waste management and manufacturing systems; however, outcomes are highly sensitive to methodological decisions, particularly end-of-life (EoL) allocation approaches. This study examines how cut-off and substitution approaches affect the energy performance and decarbonisation potential of high-density polyethylene (HDPE) injection moulding systems. A dual framework is adopted: first, a literature review examines methodological sensitivities in EoL modelling; second, a quantitative case study assesses industrial-scale primary data for the production of durable HDPE bottles (300 mL). The LCA model integrates specific technical parameters, including a 220 °C melt temperature and a 36 s cycle time, ensuring a realistic representation of manufacturing conditions. The results indicate that allocation choices significantly influence calculated impacts, sometimes reversing the relative ranking of configurations. Substitution-based approaches report higher benefits by crediting avoided primary production, while cut-off logic provides more conservative estimates. Quantitative analysis shows that transitioning from open-loop to fully closed-loop configurations reduces cumulative energy demand by 3.2% and freshwater emissions per functional unit by 2.8%. Furthermore, the study identifies a ‘landfill paradox’ specific to HDPE waste within transitional energy systems: due to the carbon sequestration effect of landfilled polymers and current grid emission factors, landfilling exhibits a lower net carbon footprint (0.03 kg CO₂-eq./kg) than high-efficiency incineration (1.54 kg CO₂-eq./kg). These findings highlight that circular economy evaluations are strongly shaped by methodological assumptions, with direct implications for energy policy. Bridging the gap between specific industrial processing parameters and end-of-life allocation logic underscores the need to incorporate primary industrial data and transparent allocation frameworks to support reliable decision-making in the transition toward low-carbon and energy-efficient manufacturing systems. Full article

Aluminum multifunctional housings can enhance circularity in electronics by replacing polymer enclosures while integrating heat sinking and electronic functions via laser direct structuring (LDS). Within the ALU4CED concept, we applied an IR-compatible LDS lacquer on aluminum, formed conductive tracks by electroless Cu/Ni/Au metallization, assembled components, and assessed end-of-life recyclability. Controlled remelting trials compared three disassembly levels: complete housings with PCBs and components, housings without PCBs, and housings with only integrated tracks. Metal yield rose from 81.4% for complete assemblies to 93.2% after PCB removal, while leaving integrated LDS tracks did not measurably penalize recovery. Only the complete electronics variant showed critical contamination (Cu = 1.64 wt.% vs. 0.25 wt.% limit for EN AC 4343); after PCB removal, composition remained close to the reference and major elements (Si, Mg, Fe) stayed within specification. Prefil testing indicated very low total inclusion content (0.006/0.001/0.002 mm²·kg⁻¹), confirming high melt cleanliness despite coatings. Following remelting → billet casting → extrusion, tensile properties (Rm ≈ 120–123 MPa, Rp0.2 ≈ 59–61 MPa, A ≈ 29–33%) were comparable to the reference profile. These results demonstrate the technological feasibility of closed-loop recycling for LDS functionalized aluminum housings and inform clear Design-for-Recycling guidance: design for rapid PCB removal, allow LDS layers to remain during melting, and maintain compatibility with the 4343 family to enable efficient internal recycling. Full article

High-efficiency energy storage technologies have become particularly crucial with the ever-increasing demand for energy in recent years. Research on polymer nanocomposite dielectric materials has emerged as a prominent focus. Particularly, there is an urgent demand for the development of advanced dielectric film materials that exhibit superior energy storage performance over a wide temperature range. To this end, this study aims to investigate the effect of the molecular weight of reduced polyaniline (R-PANI) on the dielectric properties of all-organic composite films based on high-temperature-resistant polyetherimide (PEI). All-organic R-PANI/PEI composite films were fabricated by blending PEI matrix with R-PANI of varying molecular weights. Through combined density functional theory (DFT) calculations and experimental measurements, the blocking mechanism of R-PANI on charge carrier migration within the composite films was elucidated, showing a significant enhancement in the discharge energy density of PEI polymers while maintaining high charge–discharge efficiency. With charge–discharge efficiency maintained above 95%, R-PANI3/PEI achieved a discharge energy density of 2.36 J cm⁻³ at room temperature, nearly double that of pristine PEI (1.2 J cm⁻³). At 150 °C, the 1.0 wt% R-PANI3/PEI composite film retained a discharge energy density of 2.27 J cm⁻³ with a charge–discharge efficiency of 89.2%, outperforming pure PEI (1.1 J cm⁻³, 85.1%). These findings provide a new strategy for the design of all-organic composite dielectric films and demonstrate the potential of R-PANI in the application of high-performance capacitors and electrical energy storage. Full article

Ultra-high-speed cutting (UHSC) has emerged as a transformative manufacturing technology aimed at overcoming the long-standing machining challenges associated with high-performance difficult-to-machine composites (HPDMCs). These materials—comprising silicon-based, metal matrix, and carbon fiber-reinforced polymers—are critical to strategic sectors such as aerospace and high-end equipment. This review adopts a distinctive “material-tool-process-equipment” synergistic innovation framework as its core analytical lens. Within this framework, it systematically outlines advances in UHSC, including the fundamental mechanisms of damage suppression and surface integrity enhancement under ultra-high strain rates. Innovative process methods such as laser-assisted and ultrasonic-assisted machining are examined in detail. This review also provides a mechanistic analysis of two key enabling technologies—tool micro-texturing and functional coatings—highlighting their roles in interfacial tribological regulation and physicochemical protection. Furthermore, dedicated equipment systems and stability optimization strategies essential for technological implementation are presented and evaluated. By synthesizing the current state of the field, this review identifies persistent bottlenecks and, guided by the proposed framework, suggests targeted future research directions: deep integration of smart manufacturing technologies, development of synergistic multi-energy-field processing, and enhanced adaptability to extreme service environments. This work not only consolidates the current knowledge in UHSC but also outlines a clear pathway for its evolution into a fully autonomous, efficient, and reliable manufacturing paradigm. Full article

Background: The transition from fossil-derived polymer additives to renewable alternatives is essential to mitigate environmental persistence and ensure chemical safety within the plastics industry. This review provides a comprehensive overview of recent developments in bio-based functional additives and their integration into circular economy frameworks. Methods: Following PRISMA guidelines, a systematic literature search was conducted using the Scopus database for studies published between 2023 and 2026. Search terms targeted bio-based plasticizers, flame retardants, antioxidants, and compatibilizers. Studies were screened against predefined inclusion criteria, specifically focusing on experimental validation in polymer matrices, while data mining was employed to map emerging research fronts. Results: From an initial 996 records, 54 studies were selected after removing duplicates and ineligible articles. The findings highlight a paradigm shift from passive physical fillers toward active, multifunctional macromolecular agents. Recent literature demonstrates that targeted molecular interventions, such as phosphorylated lignin and biomimetic structures, can resolve trade-offs between ductility and thermal stability at low loadings (<5 wt%). Synthesis routes, performance outcomes, and end-of-life trajectories for each additive class are summarized. Conclusions: Bio-based additives have evolved from simple substitutes into strategic tools for the molecular programming of sustainable polymers. Although challenges regarding scalability and high-temperature processing persist, their integration into circular economy strategies establishes a clear roadmap for next-generation bioplastics. Full article

This work explores a sustainable route for producing recycled AlNiCo-based magnetic composites by incorporating end-of-life AlNiCo-5 particles into a polyamide 12 (PA12) matrix, thereby eliminating conventional debinding requirements. The study emphasizes material circularity through the reuse of mechanically recovered magnetic waste and polymeric residues. Virgin PA12 powder was used as the matrix material for high magnetic filler loadings of 40, 60, and 70 wt.% AlNiCo-5, while stearic acid was introduced to enhance interfacial compatibility and overall processability. The resulting composites were shaped into filaments and processed via material extrusion additive manufacturing, demonstrating that commercially available fused filament fabrication systems can successfully handle highly filled metal-polymer blends when supported by appropriate formulation and process parameter optimization. The findings confirm the feasibility of manufacturing flexible, functional, and resource-efficient magnetic components using widely accessible equipment, highlighting a promising pathway toward the cost-effective recycling and reuse of AlNiCo magnetic materials. Full article

Although polylactic acid (PLA) and acrylonitrile–butadiene–styrene (ABS) are among the most widely used polymers in material extrusion, their limited toughness and energy-absorption capacity often restrict the structural performance of 3D-printed functional components. To address the limited comparative understanding of how thermoplastic polyurethane (TPU) modifies the deformation behavior and phase characteristics of these two polymer systems, this study presents a multi-analytical evaluation of TPU-reinforced PLA and ABS blends. To this end, both polymers were blended with TPU at 10–50 wt% and processed into filaments via single-screw extrusion. The resulting filaments were used to fabricate ASTM D638 Type I tensile specimens via material extrusion under matrix-specific, but internally consistent, printing parameters. For each composition, five specimens were tested to obtain representative values of tensile strength, elongation at break, and toughness. In addition to conventional tensile testing, the evolution of strain during deformation was monitored using digital image correlation (DIC), enabling full-field characterization of local deformation behavior. To ensure experimental reliability, specimen masses were carefully controlled, and the datasets were analyzed using MATLAB. Thermal properties were investigated by differential scanning calorimetry (DSC) to determine the influence of TPU on glass transition, melting behavior, and phase mobility, and to relate these thermal characteristics to the mechanical response of the blends. The incorporation of TPU significantly increased ductility and energy absorption in both polymer matrices, although the magnitude of improvement differed. ABS/TPU blends exhibited the highest toughness enhancement, reaching 221.4% at 30 wt% TPU, while PLA/TPU systems showed nearly a twofold increase at 20 wt% TPU. DIC analysis further revealed a transition from localized brittle deformation in neat polymers to more distributed plastic deformation with increasing TPU content. DSC results indicated reduced crystallinity in PLA-rich blends and enhanced segmental mobility in ABS-based systems, consistent with the observed mechanical behavior. Overall, the combined mechanical, optical, and thermal analyses demonstrate that the optimal TPU content is matrix-dependent, providing practical guidelines for tailoring PLA- and ABS-based filaments to achieve a controlled balance between stiffness, ductility, and energy absorption in material extrusion applications. Full article

Metal packaging materials remain fundamental across food, beverage, pharmaceutical, cosmetic, and technical sectors owing to their combination of mechanical robustness, total light and gas barrier performance, thermal resistance, and established recyclability. Aluminum alloys, tinplate, tin-free steel (TFS/ECCS), stainless steels, metal–matrix composites (MMCs), and metal–polymer or metal–paper laminates define distinct metal-based packaging architectures whose metallurgical and interfacial design governs forming behaviour, corrosion and migration pathways, coating integrity, and mechanical reliability. In this review, these architectures are examined from a materials- and systems-oriented perspective, linking composition, microstructure, processing routes, and surface engineering to functional performance across rigid, semi-rigid, and flexible formats. The analysis also considers the ongoing transition from bisphenol A (BPA)-based epoxy linings to BPA-free and hybrid coating chemistries, the use of nano-structured metallic and metal-oxide surfaces, and the role of composite laminates in which thin metallic foils are combined with polymeric or paper-based structural layers. These material and architectural aspects are discussed together with safety, regulatory, and circularity considerations that increasingly influence the design and selection of metal-based packaging. Ion migration, coating degradation, and corrosion under realistic storage environments are considered in relation to EU, FDA, ISO, and sector-specific requirements, while attention is also paid to the contrast between well-established closed-loop recycling infrastructures for aluminum and steel and the more complex end-of-life management of coated metals and multilayer laminates. The review provides a unified framework connecting materials selection, metallurgical design, processing, performance, regulatory compliance, and sustainability in metal-based packaging systems. Applications spanning consumer goods, pharmaceuticals, cosmetics, and advanced electronics are integrated to support an overall understanding of how metallic and hybrid metal-based architectures underpin functional reliability and life-cycle sustainability. Full article