The use of natural resources for the production of biodegradable packaging is currently the focus of extensive scientific research aimed at providing a sustainable alternative to petrochemical‐derived plastics. In this context, this study investigates a biocomposite film using Manihot esculenta starch (MS) as the matrix, reinforced with Rhecktophyllum camerunense (RC) fibers. The RC fibers were extracted via stagnant water retting for 12 days. The composites were fabricated using the solution casting method, with MS as the matrix, glycerol as the plasticizer, and RC fibers (mesh size ≤ 0.30 mm) as reinforcement. Three fiber content levels were studied (3, 6, and 9 wt% relative to the dry starch weight). The glycerol‐to‐starch and water‐to‐starch mass ratios were set at 30 wt% and 2000 wt%, respectively. The composites’ physical, chemical, and mechanical properties were characterized according to standardized protocols. The results revealed comparable chemical structures across all formulations. Notably, the composite containing 3 wt% RC fibers (ARC3) demonstrated optimal strength and flexibility, with a tensile strength of 19.99 MPa, a Young’s modulus of 395.25 MPa, and an elongation at break of 47%, making it the most balanced in terms of mechanical performance. Consequently, the ARC3 formulation is recommended for biodegradable packaging applications.
Although air layers are known to improve thermal protection, the influence of engineered air‐cavity volume in double‐layer polyimide/wool fabrics on the combined flame‐retardant, thermal‐insulating, and comfort performance remains poorly understood. This study addresses this gap by systematically designing hexagonal air‐cavity structures through the differential shrinkage of polyimide and wool fibers. Experimental characterization and finite element analysis demonstrated that optimizing cavity volume significantly improved multifunctional performance. The fabric with the largest air cavity exhibited a 30%–40% reduction in damage length, a 32.2% decrease in peak heat release rate (PHRR), and a 59.6% reduction in smoke production. Infrared thermography and thermal protection tests further showed a 13.0% improvement in insulation rate and a 15.8% increase in thermal protection performance (TPP). Air and moisture permeability were also enhanced, demonstrating improved wearer comfort without compromising protection. These findings establish the critical role of engineered air‐cavity volume in balancing thermal insulation, flame retardancy, and comfort, providing a practical design strategy for advanced protective textile systems.
Rubber matrix was controlled to be hydrophilic, swellable, and conductive, by mixing with varied amounts of epichlorohydrin rubber (GECO), polyethylene oxide (PEO), and ethylene–vinyl acetate (EVA) polymers, et cetera. Higher concentration of the epichlorohydrin rubber (GECO) resulted in higher curing times (ts2 and t90), high torque values (ML, MH, and ∆M), high crosslinking density, and higher stiffness (MPa). Sample GP1 recorded highest strength due to the high content (70 part per hundred of rubber [phr]) of the epichlorohydrin rubber (GECO). All the compositions exhibited wetting and hydrophilic behavior, with contact angle < 80°, upon submerging into petrol, diesel, kerosene, cooking oil, and water, respectively. The swollen composites resulted in volume increase, and dramatic drop in the electrical resistances. Based on volume strain (∆V/Vo), the gauge factor (GF = [∆R/Ro/(V/Vo]) deduced for the compounds was within approximately 1.3 × 103–9.6 x 103, which is the first to be reported for liquids (petrol, diesel, kerosene, cooking oil, and water), to the best of our knowledge. These GF values were higher and comparable to many other strain gauges made of rubber-reinforced/coated with graphene, and carbon nanotubes (CNTs), et cetera. Thus, the current compositions exhibit multifunctional capabilities for liquid/chemical sensing, soft robotics, agro-mulching, and real-time soil moisture monitoring applications.
Due to the fascinating behavior of the late-transition-metal (LTM) catalysts for co-/homo-polymerization of olefins, especially polar monomers, they have consistently attracted researchers’ attention. Synergistic effects between the active metal centers have further augmented this interest. Among these structures, oxo-nitrogenated cobalt (II) catalysts are widely used for the polymerization of dienes. Herein, we report the synthesis of an oxo-nitrogenated dinuclear Co(II) catalyst, which was carefully characterized using 1H NMR, Fourier transform infrared (FT-IR), energy dispersive X-ray (EDX), mass, atomic force microscopy (AFM), and scanning electron microscopy (SEM). The catalyst was tested for the polymerization of methyl methacrylate (MMA), a widely used monomer for producing polymethyl methacrylate (PMMA), a transparent thermoplastic with high chemical and thermal stability used in coatings, optics, and biomedical applications, in the presence of a modified methylaluminoxane (MMAO), the cocatalyst. The highest activity was obtained at an [Al]/[Co] molar ratio of 1000:1, Tp = 40°C, and tp = 2 h, giving 66.9 g PMMA/mmol Cat h. Interestingly, the morphology of the given sample particles was spherical under specific conditions. The microstructure study of the PMMA made by the catalyst showed syndiotactic at 57.3%, atactic at 29.5%, and isotactic at 13.1%, respectively. In addition, the microstructural analyses of PMMA exhibited branching densities in the range of 221–330/1000C, a narrow PDI of 1.93, and a molecular weight of M¯w = 1.180 × 105 g/mol for the given samples. Although no evidence of a cooperative effect was observed in terms of selectivity, the reasonable activity of the catalyst may suggest the presence of such an effect.
In this study, a systematic investigation was conducted to identify the critical BaTiO3 (BT) loading in electrospun poly(vinylidene fluoride) (PVDF) nanofibers under controlled processing conditions for developing high-performance wearable piezoelectric sensors. Composite nanofiber mats with loadings of 0, 5, 10, and 15 wt% BT were fabricated and comprehensively characterized using field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile testing. The piezoelectric performance of the sensors was evaluated by measuring the output voltage under applied calibrated mechanical forces. Results indicated that the sample containing 10 wt% BT offered the best balance between structural integrity and electromechanical performance. This sample maintained uniform morphology and prevented defect formation, such as beading, while significantly increasing the β-phase content to 86.62% and the degree of crystallinity to 49.67%. Furthermore, tensile strength and elongation at break improved by 68% and 65%, respectively, compared to neat PVDF. In terms of sensing performance, this identified composition achieved a peak sensitivity of 1.420 V/N (a 40% increase) with a high correlation coefficient (R2 = 0.9959) across the tested force range, indicating a stable linear response and high reliability for pressure-sensing applications. The findings demonstrate that a 10 wt% BT loading creates a balanced formulation by maximizing synergistic effects of β-phase formation and mechanical reinforcement of the PVDF matrix, while preventing nanoparticle agglomeration. The resulting nanocomposite provides a simultaneous combination of high sensitivity, broad linear response, and suitable mechanical flexibility for wearable sensors.
Rubber products are widely used in various fields because of its excellent elasticity, but aging will seriously affect the performance of rubber parts, reduce economic benefits, and bring safety hazards. Many traditional organic antioxidants in rubber industry have biotoxicity, thus developing new antioxidants is urgent. Cerium dioxide containing rare earth elements shows unique advantages in improving the resistance of rubber to thermal oxidation and ultraviolet aging due to cerium’s strong ability to store and release oxygen, as well as its ability to combine with free radicals and its ability to absorb ultraviolet light. In this work, cerium dioxide nanoparticles with uniform size, homogeneous dispersion, and regular morphology were prepared by hydrothermal method and added into rubber as reinforcing filler to obtain butyl rubber/cerium dioxide nanoparticles (butyl rubber/CeO2 NPs) composites. Compared to pure butyl rubber, the thermal stability, and damping properties of butyl rubber/CeO2 NPs composites were improved, and the composites showed an increase in tensile strength of 13.4% and 12.5% and elongation at break retention of 10.3% and 2.2% after thermo-oxidative and UV aging, respectively. These results confirm that nano-CeO2 significantly improves thermal-oxidative and UV aging resistance, showing great potential as a new eco-friendly antioxidant for the rubber industry.
The food packaging sector widely employs injection-molded items, which are often used only once before disposal. The use of polyhydroxyalkanoates (PHAs) to fabricate these items may represent an effective solution to reduce the amount of plastic waste, but it is currently limited by their high cost, narrow processing window, and poor thermal properties. Three different blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), amorphous poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), and talc were produced via compounding and injection molding. The inclusion of an amorphous PHA in the blend improves the mechanical properties but leads to a drastic worsening of the processability via injection molding at 30 wt.%. Rheological, mechanical, and thermal characterizations of the blends were performed, along with Fourier transform infrared (FTIR) and XRD analyses. Talc serves as a multifunctional agent, improving compatibility, enhancing rigidity and thermal resistance, and reducing costs. Its primary advantage is the increase in heat deflection temperature (HDT), which can reach up to 95.7°C with the addition of 10 wt.% talc. The elastic modulus of the compound with talc nearly doubles compared to the unfilled version, reaching ~835 MPa. The MFR of the compounds remained in the range 8.8–11 g/10 min after compounding. This study underscores the potential of PHAs as materials for producing injection-molded single-use items in the food packaging sector, where biodegradability and high thermal resistance are essential.
While microplastics (MPs) derived from most petroleum-based plastics persist in the environment, their counterparts made of bioplastics such as poly(lactic acid) (PLA) offer the potential for biodegradation. However, their actual environmental fate is not solely dictated by degradation conditions, but it is also critically influenced by their processing and fabrication history, which governs their physicochemical properties. This study specifically investigates how the fabrication method of PLA MPs controls their enzymatic degradation. MPs produced through different manufacturing protocols were subjected to degradation by a commercial lipase enzyme from Aspergillus oryzae. After 28 days of enzymatic hydrolysis at pH 8.0, noticeable changes in the surface morphology of MPs were observed due to the emergence of pores ranging from hundreds of nanometers to less than two micrometers. Detailed characterizations reveal that the MPs’ fabrication pathway is a key determinant of degradation performance. Despite comparable particle size, MPs produced via different methods exhibited distinct degradation responses, as evidenced by variations in carbonyl index (CI, up to 12.0%) and crystallinity (up to c.a. 43.0%) and a decrease of the polymer’s molecular weight of up to c.a. 17.5% depending on the sample type. This study confirms the capability of the lipase enzyme to degrade PLA and underscores that the degradation performance is governed by the formation process of the polymeric particles. This highlights a critical and often overlooked aspect in MP and nanoplastic (NP) research: particles with identical chemical composition but different formation histories can exhibit markedly different biodegradation behaviors. Therefore, careful consideration of the fabrication route is essential for the accurate interpretation and comparison of biodegradation studies.
Rubber O-rings are vital sealing components in petrochemical and refinery applications, where reliable performance under harsh conditions is essential. This study employs a multianalytical approach to investigate the material composition, curing system, and performance of an industrial O-ring. Fourier transform infrared (FTIR) spectroscopy identified characteristic bands at 1394 cm-1, confirming the O-ring as a fluorocarbon elastomer (FKM), with a peak at 3428 cm-1 (attributed to N-H groups) diminishing post-Soxhlet extraction, indicating an amine-based curing system. Thermogravimetric analysis (TGA) revealed a 91.69% weight loss up to 700 degrees C, with significant degradation at 493 degrees C (58.37% loss between 400 and 550 degrees C) and a residual mass of 8.31%, suggesting minimal filler content. Mechanical testing demonstrated a modulus of 4.60 MPa, tensile strength of 5.86 MPa, strain at break of 165%, and a compression set of 41%, reflecting robust material properties. The O-ring was identified as Viton A (a vinylidene fluoride [VDF]/hexafluoropropylene [HFP] copolymer) with a diamine curing system, typical of early FKM grades used in demanding chemical environments. While FTIR identifies key functional groups, its integration with TGA (for thermal stability and filler content), Soxhlet extraction (for additive isolation), and mechanical testing provides a practical, accessible framework for reverse engineering industrial elastomers-offering actionable insights into material suitability for petrochemical sealing applications.
Conductive hydrogels have emerged as a research hotspot in the field of flexible sensing. However, existing materials commonly suffer from insufficient adhesion and limited sensitivity. In this study, a novel polyacrylic acid (PAA)-based composite conductive hydrogel (PHCP) was prepared. Hydroxypropyl methylcellulose, chitosan, and conductive polydopamine-modified polypyrrole composite particles were incorporated into the PAA hydrogel matrix to obtain a stable multidimensional crosslinked network through the synergistic effects of dynamic hydrogen-bonding and electrostatic interactions. The resulting PHCP hydrogel exhibits outstanding performance, with a fracture strain of up to 1205.5%, a tensile strength of 129.7 kPa, and a maximum adhesion strength of 21.6 kPa on substrates such as wood. The sensor demonstrates a gauge factor of 2.63 in the 150%-400% strain range and a sensitivity of 2.16 kPa-1 in the 0-10 kPa pressure range, with both response and recovery times being as short as 0.33 s. Notably, it endures 150 stretching cycles without fracture. In practical applications, the hydrogel can stably monitor joint movements of fingers, wrists, and elbows; accurately distinguish motion signals; and recognize handwritten characters such as "A," "T," "C," and "OK." Through a synergistic multicomponent design, this study addresses the challenge of simultaneously achieving mechanical stability and high sensitivity in flexible sensors, offering a novel material solution for electronic skin, wearable devices, and human-machine interaction applications.
Replacing toxic organotin catalysts in polyurethane (PU) synthesis remains a critical challenge, as current alternatives suffer from either low activity or diminished product performance. Herein, we report a new class of dual-cation Fe/Zn complexes through strategic integration of imidazolium frameworks with transition metal centers, characterized by FT-IR, nuclear magnetic resonance (NMR) spectroscopy, and single crystal X-ray diffraction (SC-XRD). These catalysts exhibit activities higher than commercial organotin and tertiary amines while maintaining excellent biocompatibility as well. Mechanistic investigations establish a 7.4-fold enhancement in conversion rates through synergistic cooperation, as imidazolium cations and Zn2+ centers both activate isocyanate groups, while coulombic repulsion between cationic moieties effectively prevents metal aggregation. This work provides both a sustainable alternative to tin catalysts for PU synthesis and a general design principle for multifunctional polymerization catalysis strategies.
Croton macrostachyus (CM) is rich in bioactive compounds, including carbohydrates, saccharides, phenolic acids, and diterpenes, known for their antibacterial, wound-healing, and anti-inflammatory properties. This study aims to leverage these properties by incorporating CM leaf extract into polycaprolactone-cellulose acetate (PCL-CA) nanofibers to develop advanced wound dressings that prevent infection and promote healing. For the first time, CM leaf extract was successfully integrated into PCL-CA nanofibers via electrospinning. The resulting composite nanofibers were subjected to a comprehensive analysis of their morphology, porosity, crystallinity, thermal stability, hydrophilicity, and mechanical strength. In vitro evaluations assessed antibacterial efficacy, wound healing, cytotoxicity, and drug release profiles. The results demonstrated that PCL-CA-CM nanofibers form interconnected, bead-free structures with fiber diameters of 326 +/- 85 nm to 374 +/- 92 nm and a porosity of 61-80%. The mats exhibited significant antibacterial activity, reducing Staphylococcus aureus (S. aureus) by 66.77-99% and Escherichia coli (E. coli) by 58.18-99%. Cytotoxicity assays confirmed minimal toxicity with cell viability exceeding 70%. Furthermore, nanofibers significantly enhanced cell migration. The incorporation of CM also improved hydrophilicity, swelling capacity, and mechanical strength of the mats. These findings collectively highlight the potential of CM-loaded PCL-CA nanofibers as an effective advanced wound care application.
The need to find sustainable substitutes for conventional plastics made from petroleum has been heightened by the global problem of plastic pollution and the depletion of fossils. Natural polymer-based bioplastics are among the most promising answers because they can lessen dependency on fossil fuels while providing cleaner and greener end-of-life (EOL) alternatives. This study provides a thorough and critical examination of the formation, functionality, and alignment of circularity of natural polymers, including cellulose, starch, chitosan, lignin, alginate, and gelatin. It also evaluates popular bioplastics, such as polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and polyhydroxyalkanoates (PHAs), pointing out their advantages and disadvantages in different industrial domains. In order to improve material functioning, the paper also examines novel blending processes, bio-based plasticizers, and new monomers. Life cycle assessment (LCA), circular design concepts, and the real-world difficulties of manufacturing scalability are given particular attention. Through creative diagrams, comparison tables, and a radar chart showing EOL paths, this paper presents a unique integrated viewpoint on the role of natural polymers in the shift to a circular bioeconomy. A critical evaluation of present policy frameworks and tactical suggestions to get beyond obstacles to broad adoption are included in the study’s conclusion. Computational material science-assisted advances in polymer chemistry and applications pave the way for a complete approach to these problems by designing for biodegradability and recyclability. This review examines the ways in which advancements in science, new legal frameworks, societal norms, and economic constraints pave the way for the shift to a circular economy of polymers.
The proliferation of single-use plastics (SUPs) has raised concerns about waste management and environmental sustainability. Polylactic acid (PLA) can be used as a green alternative, but its high cost and brittleness have hindered its widespread adoption. This paper explores the use of compatibilizer and plasticizer to enhance the compatibility and flexibility of PLA/tapioca starch (TS) biocomposites. Maleic anhydride (MA) was grafted to form PLA-g-MA and used as a compatibilizer followed by the addition of epoxidized palm oil (EPO) as a plasticizer. Results demonstrated an overall positive impact, indicating the opportunity to develop an optimized blend composition. Fourier transform infrared (FTIR) confirmed the presence of new functional groups, while thermal analysis indicated successful compatibilization. Plasticization was verified by a reduced Tg. Rheology confirmed pseudoplastic behavior with n value of 0.510 < n < 0.552 and activation energy (Ea) of 25.25 kJ/mol. Tensile tests showed that the addition of 5% PLA-g-MA improved the tensile strength by 13%, while the addition of 2% of EPO doubled the elongation at break. The Young’s modulus of the plasticized blend observed a decrease, which indicated improved ductility. Morphology confirmed compatibilization and demonstrated microfibrils. Overall, the PLA/tapioca biocomposite exhibited favorable properties, high quality, and cost-effectiveness, indicating good potential in short-term food packaging applications.
Chitosan (CS) is a cationic biopolymer that has shown unique opportunities in tissue engineering. The well-defined geometry, porosity, easy processability, and antimicrobial and antifungal properties are particularly beneficial for tissue regeneration. This review outlines the progress made in the preparation of bioinspired electrospun CS for tissue regeneration. The article concentrates on bioinspired electrospun CS and CS-based composites which have appeared in a good number of publications in the literature and enriched the field of tissue engineering. It also highlights the upscaling of electrospun nanofibers with recent advanced technologies. Finally, the overall summary, challenges, and future perspective in tissue regeneration based on bioinspired CS and related composite materials is presented.
Recent advances in flexible sensor technology have driven the widespread adoption of smart wearable devices. Pulse sensors, which monitor heartbeats, provide essential information about human health and serve as vital tools in personal health management, disease prevention, and medical diagnosis. However, developing sensor materials with high reproducibility for the precise detection of weak pulse signals remains challenging. In this work, a pulse-sensing composite conductive hydrogel (PCP) was fabricated via a five-cycle freeze-thaw method for application in traditional Chinese medicine (TCM) pulse diagnosis. The hydrogel was composed of polyvinyl alcohol (PVA), chitosan quaternary ammonium salt (CHACC), and PEDOT:PSS in an optimized mass ratio of PVA:CHACC = 7:3. It exhibits outstanding tensile strain (567%), a broad sensing range (0%-250%), fast response (0.7 s), excellent repeatability (over 1000 cycles), and high conductivity (1.5 S/m). These properties allow precise monitoring of motion signals from different body regions with sustained stability. Furthermore, the hydrogel showed antibacterial activity against Staphylococcus aureus with an inhibition zone diameter of 18.2 +/- 0.5 mm, indicating enhanced biosafety. An integrated three-channel wristband sensor based on this hydrogel was also developed, enabling real-time and accurate detection of human pulse signals. This system provides a promising platform for digitized pulse diagnosis in wearable health monitoring.
Disruptions in the skin restoration process can impair wound healing and lead to severe clinical complications, particularly in environments prone to microbial colonization and biofilm formation. Modern wound dressings are, therefore, designed not only to restore tissue integrity but also to actively modulate the wound microenvironment and mitigate infections caused by multidrug-resistant microorganisms. In this context, polymeric matrices play a fundamental role by providing structural support, moisture regulation, and controlled delivery capabilities that guide cellular responses and tissue regeneration. Recent advances have focused on integrating naturally derived bioactive agents, such as stem cell-derived components, vitamins, growth factors, and phytochemicals, into polymer-based systems to enhance their therapeutic performance due to their effectiveness depending strongly on the protective and regulatory functions of the polymeric carrier. Polymeric platforms enable stabilization, sustained release, and targeted activity of these molecules, thereby improving their bioavailability and functional impact within the wound site. This review examines the wound healing process from a polymer engineering perspective and discusses emerging strategies for incorporating natural and bioactive molecules into polymeric wound dressings to address the dual challenge of tissue regeneration and antimicrobial resistance (AMR). Emphasis is placed on how polymer properties govern therapeutic outcomes. Finally, we outline current advantages, limitations, and future directions in the design of advanced polymer-based wound dressings capable of enhancing healing while combating resistant microbial infections.
Electrospinning (ES) techniques produce fibrous scaffolds that closely mimic the three-dimensional architecture of the extracellular matrix (ECM), providing a favorable microenvironment for cell proliferation, migration, differentiation, and function within a supportive framework. Replicating this native structure with nontoxic materials is essential for tissue regeneration (RG). Polyhydroxyalkanoates (PHAs), particularly polyhydroxybutyrate (PHB), are a class of natural polymers that have been extensively studied for applications in tissue engineering (TE). The inherent biocompatibility, biodegradability, piezoelectric properties (PEs), and mechanical strength of this biological macromolecule make it an attractive candidate for scaffold fabrication, as its degradation by-products exhibit very low cytotoxicity. Despite these advantages, PHB exhibits intrinsic limitations such as hydrophobicity, slow degradation rate, and brittleness, which restrict its broader applicability. To overcome these challenges, various modification strategies, including blending, nanocomposite (NC) incorporation, and surface modification, have been developed to enhance its physicochemical and biological performance. This review comprehensively presents recent advancements in the design and fabrication of PHB-based electrospun scaffolds (ES-Ss), highlighting their structural, mechanical, and biological properties. Additionally, it explores their diverse in vitro and in vivo outcomes across multiple tissue types, including bone, cartilage, skin, cardiac, and neural tissues. This study further addresses current challenges and future perspectives to optimize PHB-based scaffolds for clinical translation in regenerative medicine.
Polymer composites and polymer solutions are extensively studied in polymer science. For polymer solutions, the viscosity is a key property relevant for many applications, where the intrinsic viscosity plays an important role. A recent self-consistent theoretical description revealed a novel equation relating solution viscosity to concentration and intrinsic viscosity together with characteristic scaling exponents, depending on the concentration regimes. In particular, for small concentrations, an exponent of 3 is predicted. The focus of this work is to challenge this novel description, in particular, the exponent 3. Therefore, a huge amount of data from the literature is reanalyzed, and a novel equation is fitted to the data. Some older data are only accessible from graphs given in the publications; nevertheless, a digitization tool was applied to access these data for analyzing.
High-velocity fragment impact on aircraft thin-walled aluminum alloy structures typically induces severe debris cloud generation, which causes widespread secondary damage to internal equipment and greatly impairs structural survivability and post-damage repairability. Polyurea, as a lightweight hyper-elastomeric protective material, shows great potential in mitigating impact-induced damage, while its inhibitory effect and underlying mechanism on post-target debris cloud effects remain to be fully elucidated. In this study, we designed and fabricated polyurea-coated aluminum plate specimens with different coating configurations (rear-face single-sided coating and double-sided sandwich coating) and conducted systematic ballistic impact tests under 1300-1400 m/s fragment impact using a 14.5 mm ballistic gun system. The optimized test setup enabled direct and quantitative observation of the regulation effect of polyurea coatings on post-target debris cloud evolution. Experimental results show that polyurea coatings can effectively suppress debris cloud diffusion and reduce secondary damage, and the rear-face coated configuration (Type A) exhibits optimal post-target effect mitigation performance: the debris cloud dispersion angle is reduced from 67.5 degrees +/- 1.2 degrees (uncoated plate) to 58.2 degrees +/- 1.1 degrees, and the maximum distribution radius of secondary impact craters on the witness plate is reduced by 46.7% compared with the uncoated specimen. Furthermore, a finite element model coupled with the adaptive FEM-SPH method was established and validated against experimental data to reveal the physical mechanism of polyurea's protective effect. The results demonstrate that the excellent hyperelasticity, high fracture strain, and energy absorption capacity of polyurea are the core factors for debris suppression: the polyurea coating achieves debris entrapment through large deformation and contraction, dissipates impact energy via viscoelastic dissipation, and modulates stress wave propagation to reduce aluminum substrate spalling and debris generation. This study clarifies the inhibitory mechanism of polyurea coatings on post-target secondary effects under high-velocity impact and provides valuable experimental and theoretical guidance for the lightweight protective design of aircraft thin-walled structures using polyurea materials.
