ABSTRACT A worldwide consensus has been reached that waste recycling and reuse play a crucial role in carbon emission reduction. Recently, growing interest has emerged in developing sandwich structures using recyclable items by leveraging their intrinsic structural benefits. In this study, a novel eco‐friendly honeycomb sandwich panel was designed adopting widely consumed beverage bottle caps. The assembled core layer was fabricated by a simple interlocking method with minimal machining process, while the face sheets were manufactured using carbon fiber‐reinforced polymer to provide excellent load resistance. Quasi‐static compression and three‐point bending experiments were conducted to characterize the mechanical performance, and the life cycle assessment methodology was employed to quantify the environmental footprints. The results indicated that the interlocking assembly strategy of the core layer effectively enhanced the load capacity through structural interaction mechanisms. Meanwhile, the reuse of bottle caps combined with the minimal machining concept reduced the environmental impacts. Although the eco‐mechanical efficiency of the current sandwich panel was constrained by the significant environmental burden associated with the production of virgin carbon fiber prepreg, future research will investigate the potential benefits of adopting the reuse strategy in face sheet preparation.
ABSTRACT To resolve the conflict between flame retardancy and mechanical properties in glass fiber (GF)‐reinforced polyamide 6 (PA6) composites, a synergistic strategy combining bulk synergy and interfacial functionalization was developed. A flame‐retardant system comprising melamine polyphosphate (MPP) and aluminum diethylphosphinate (ADP) as the main agents, together with polytetrafluoroethylene (PTFE) as an anti‐dripping agent, was incorporated to promote char formation and gas‐phase inhibition within the PA6 matrix. The composites were prepared via melt blending followed by injection molding. To further suppress the “wick effect” of GF, MPP was covalently grafted onto the GF surface via a silane coupling agent, constructing a multifunctional interface that enhances both flame retardancy and mechanical performance. A synergistic strategy combining bulk flame retardancy (MPP/ADP/PTFE) and interfacial MPP‐grafted GF is developed for PA6/GF composites, achieving UL‐94 V‐0, LOI 29.2%, reduced heat release, and improved mechanical properties (tensile 133.2 MPa, flexural 157.2 MPa, impact 10.7 kJ/m 2 ). Finite element analysis validates optimized stress dispersion. This work offers an effective approach for designing high‐performance PA6/GF composites with integrated flame retardancy and mechanical robustness.
ABSTRACT To clarify the applicability of double‐double (DD) lay‐ups in open‐hole fiber metal laminates (FMLs), this study investigates glass laminate aluminum reinforced epoxy (GLARE) laminates with conventional QUAD lay‐ups and stiffness‐equivalent DD lay‐ups under different 0° fiber contents. The open‐hole tensile response, damage evolution mechanisms, and size effects are systematically examined. The results show that both QUAD and DD laminates exhibit a progressive damage process involving strain concentration around the hole, intralaminar damage initiation, interfacial delamination growth, and final through‐thickness fracture. However, their damage organization mechanisms are markedly different. In QUAD laminates, continuous 0° fiber plies enhance the load‐bearing capacity but intensify the stress concentration around the hole, thereby accelerating matrix damage and delamination in the composite layers and further inducing deflected fracture of the aluminum layers. In contrast, DD lay‐ups promote load redistribution among plies with different orientations, thereby modifying the spatial evolution of matrix and interfacial damage and maintaining a more stable fracture path close to the net‐section direction. As the 0° fiber content decreases, the governing role of fiber fracture in final failure gradually weakens, while matrix damage and delamination become increasingly dominant.
ABSTRACT This study investigated the short‐term salt‐fog response of carbon/basalt hybrid fiber reinforced epoxy composite laminates with different fiber volume fractions and carbon/basalt interface numbers. Tensile and three‐point bending tests, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) were used to evaluate the mechanical response and associated mechanisms. Fiber volume fraction significantly affected tensile strength, whereas the number of carbon/basalt interfaces showed no monotonic effect. Most laminates exhibited an increase in tensile strength during the first 6 h of exposure, after which tensile strength remained statistically stable, with changes within approximately ±6%. In contrast, flexural properties were more sensitive to stacking architecture and salt‐fog exposure. The laminate with 10 carbon/basalt interfaces exhibited the highest initial flexural strength and modulus, 421.60 MPa and 33.22 GPa, respectively, but also the largest reductions after 96 h of exposure, with strength and modulus decreasing by 32.10% and 17.17%. FTIR indicated moisture‐related changes in hydrogen‐bonding environments without extensive destruction of the epoxy backbone. DSC results demonstrated that short‐term salt‐fog behavior is governed by competing thermal‐conditioning and moisture‐related effects, while fiber volume fraction and through‐thickness stacking architecture control the tensile and flexural responses, respectively.
ABSTRACT Epoxy‐based carbon‐fiber‐reinforced polymer (CFRP) composites are increasingly used in high‐performance applications, yet their highly cross‐linked and chemically resistant matrices remain difficult to recycle sustainably. Conventional recycling methods typically depend on high temperatures, aggressive chemicals, or intensive mechanical processing, which can degrade fiber integrity and impose substantial environmental burdens. Here, we report a hybrid bio‐enabled recycling strategy that integrates targeted physicochemical pretreatments, fungal‐mediated epoxy degradation, and low‐temperature thermal post‐processing to selectively weaken and remove epoxy matrices under comparatively mild conditions. Acetic‐acid solvolysis, ultraviolet irradiation, and oxidative pretreatments increased epoxy bioavailability through surface oxidation, bond cleavage and defect formation. Among four fungal strains investigated, Aspergillus flavus exhibited the highest degradative activity, achieving 15.5% composite mass loss within 30 days following solvolysis pretreatment, compared with 2.1% for Aspergillus niger . Microscopic and spectroscopic analyses revealed progressive resin thinning, fiber exposure and oxidative–hydrolytic depolymerization, with cumulative mass loss reaching 25.5% over 60 days. The 24–48 h high‐rate interval informed a cyclic treatment that produced increased matrix erosion and fiber exposure. Subsequent low‐temperature treatment at 425°C enabled clean fiber recovery with reduced volatile formation. These findings establish a mechanistically informed biological‐thermal pathway for CFRP recycling that supports progress toward circular composite material systems.
ABSTRACT Carbon fiber reinforced polymer composites (CFRPs) have attracted increasing attention for their superior properties. However, the insufficient thermal stability and structural discrepancy of conventional commercial epoxy‐based sizing agents lead to inherent limitations in the manufacture and application of CFRPs employing thermoplastic matrices such as polyamides and poly (ether‐ether‐ketone) (PEEK) resins. Towards this end, an epoxy‐terminated cross‐linkable emulsion sizing agent was prepared to improve heat resistance and interfacial matching with the PEEK matrix. This strategy utilizes aqueous diazonium reactions to decorate carbon fibers (CFs) surfaces with aniline ancillaries, which undergo chemical bonding with epoxy groups in Epoxy‐terminated bisphenol fluorene and 4,4′‐difluorobenzophenone binary copolymer (EP‐PBEK) to effectively improve the interfacial wettability between CFs and Poly (ether‐ether‐ketone) (PEEK) resin. The aqueous EP‐PBEK sizing agent which was formulated through an emulsion technique is environmentally sustainable and yields uniformly distributed nanoparticles with a mean diameter of roughly 192.7 nm. Experimental findings revealed that CF/PEEK composites modified with 1.5 wt.% EP‐PBEK possessed optimal interfacial performance. The values of interlaminar shear strength (ILSS), interfacial shear strength (IFSS) as well as flexural strength were measured at 94.29, 93.63 and 992.63 MPa separately, which were enhanced by 75.72%, 96.71% and 57.30% in contrast to DCF/PEEK composites. This study presents a green and efficient strategy to tailor high‐temperature‐resistant interfaces in CF/PEEK composites.
ABSTRACT Agricultural‐residue fillers can lower the material footprint of biodegradable composites, but their hydrophilic surfaces often weaken polyester interfaces. This study resolved the individual and combined effects of maleic‐anhydride‐grafted poly(lactic acid) (MAH‐g‐PLA) and a multifunctional epoxy chain extender (ADR) in a 70/30 poly(lactic acid)/poly(butylene adipate‐co‐terephthalate) blend containing Zizania latifolia leaf powder (ZLP). Low‐filler prescreening, single‐factor gradients, and factorial controls were assessed by tensile testing, melt mass‐flow rate (MFR), dynamic rheology, Fourier‐transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, and thermogravimetry. The balanced formulation contained 5 wt% ZLP, 5 wt% MAH‐g‐PLA, and 0.5 wt% ADR. MAH‐g‐PLA increased tensile strength from 17.75 ± 0.81 to 26.54 ± 1.94 MPa and raised the onset degradation temperature from 294.64°C to 306.72°C. Subsequent ADR addition increased elongation at break from 9.97% ± 0.71% to 43.76% ± 5.44%, reduced MFR from 18.97 ± 0.60 to 15.13 ± 0.35 g/10 min, and increased G ′ from 65 to 160 Pa at 0.1 rad s −1 . The combined evidence indicates complementary interfacial‐load‐transfer and melt‐viscoelastic effects, establishing a factor‐resolved composition–structure–property framework for reactively compatibilized ZLP/PLA/PBAT biocomposites.
ABSTRACT Accurate prediction of the tribological behavior of fiber‐reinforced polymer composites is essential for assessing their performance under different service conditions. This study presents an integrated statistical and machine learning framework for analyzing the dry sliding tribological behavior of carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) composites under different environmental conditions, aging durations, and applied loads. A previously published dataset comprising 60 observations was analyzed using exploratory data analysis, four‐factor analysis of variance (ANOVA), and five machine learning algorithms. Model performance was evaluated through hyperparameter optimization, nested cross‐validation, repeated k ‐fold validation, and leave‐one‐out cross‐validation (LOOCV), while feature importance and SHAP analyses were used for model interpretation. Aging duration was identified as the dominant factor affecting specific wear rate (SWR), whereas coefficient of friction (COF) was primarily influenced by reinforcing fiber material. Gradient boosting provided the best SWR predictions, while linear and ridge regression produced the most reliable COF predictions. The agreement between ANOVA and interpretable machine learning analyses demonstrated physically meaningful predictive relationships. The proposed framework integrates statistical inference, predictive modeling, and interpretability to support tribological assessment and data‐driven engineering decisions.
ABSTRACT To address the challenges of insufficient thermal conductivity, unstable friction behavior, and interfacial wear of carbon fiber‐reinforced friction composites (CFRFCs), multiscale GNPs/nano‐SiO 2 and VGCFs/nano‐SiO 2 composite coatings were fabricated on preform surfaces by air spraying, followed by resin impregnation, hot pressing, and curing to obtain CFRFCs. The dimensional synergy between zero‐dimensional nano‐SiO 2 and carbon fillers with different geometries was systematically investigated. Results showed that nano‐SiO 2 played distinct roles in the two systems. In GNPs/nano‐SiO 2 , nano‐SiO 2 acted as point‐like spacers and defect fillers between two‐dimensional GNP sheets, forming a point–plane structure that promoted heat‐transfer pathways and lubricating film stability. In VGCFs/nano‐SiO 2 , nano‐SiO 2 was embedded in the one‐dimensional VGCF network, forming a line–point interlocking structure that enhanced interfacial anchoring and shear resistance. At a GNPs/nano‐SiO 2 mass ratio of 5:5, CFRFCs showed the best overall balance. Compared with the single GNPs‐reinforced composite, the GNPs/nano‐SiO 2 hybrid composite achieved a dynamic friction coefficient of 0.118, a dynamic/static friction coefficient ratio of 0.92, and a shear strength of 1.37 MPa at 2.96 MPa, representing increases of 9.3%, 24.32%, and 5.3%, respectively. The in‐plane thermal conductivity reached 0.51 W/(m·K), and the wear rate remained low at 0.92 × 10 −12 m 3 /(N·m). This work provides a multiscale dimensional‐synergy strategy for designing friction‐stable and wear‐resistant CFRFCs.
ABSTRACT To address the sedimentation and instability of cement slurries under the high‐temperature and high‐pressure conditions of deep and ultra‐deep well cementing, a novel organic–inorganic hybrid suspension stabilizer, LXCH, was designed and synthesized. Four functional monomers were copolymerized in situ with modified nano‐montmorillonite to construct a hybrid framework combining rigid inorganic components with flexible polymer chains. The target structure was confirmed by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and X‐ray photoelectron spectroscopy, while thermogravimetric analysis demonstrated excellent thermal stability, with no obvious degradation below 282°C. At 210°C and 90 MPa, the incorporation of LXCH significantly improved slurry suspension stability, resulting in a hardened cement column density difference below 0.04 g/cm 3 , without adversely affecting rheological properties, thickening behavior, or compressive strength. Rheological frequency sweeps, hydrodynamic radius and zeta potential measurements, environmental scanning electron microscopy observations, and molecular dynamics simulations revealed a dual‐network stabilization mechanism. Partial polymer crosslinking forms an initial chemical network at relatively low temperatures, while hydrophobic association at elevated temperatures generates a dynamic physical network. Together with electrostatic adsorption and steric hindrance, these networks effectively maintain slurry stability, providing a promising strategy for high‐performance stabilizers for deep and ultra‐deep well cementing.
ABSTRACT In this study, the role of carbon‐basalt hybridization in improving the impact resistance and damage tolerance of bonded single lap joint has been evaluated. Therefore, four configurations of unidirectional plies stacked in cross ply sequence have been experimentally evaluated under low‐velocity impact and tensile‐after‐impact (TAI) loading. The configurations consist of two pure laminates (CCCC and BBBB) and two inter‐ply hybrids (CBBC and BCCB). Impact testing was performed using a drop‐weight apparatus, and residual strengths were measured through tensile testing on pre‐impacted samples. Results at 2.5 J impact show that (CCCC) laminates exhibit the highest peak impact forces, i.e., (1968.9 N) and residual strengths (3371.2 N), while (BBBB) and BCCB demonstrate lower stiffness but greater damage diffusion and energy absorption. The CBBC hybrid achieved the most effective balance, retaining tensile capacity close to (CCCC) joint configurations, (3360 N) at low energies and exhibiting enhanced impact resistance (2503.3 N, 27.14% increase), due to synergistic stress redistribution between carbon and basalt layers. SEM images further support these results by showing that the sandwiched basalt layers diffuse and spread damage, preventing cracks from directly reaching the adhesive layer, as occurs in (CCCC) joints, and thereby shifting the failure mode toward adhesive‐dominated behavior under tensile loading.
ABSTRACT Glass fiber‐reinforced polymer (GFRP), as an advanced transparent composite, has attracted considerable attention in architectural decoration. However, its highly directional light‐transmission characteristics limit its application in aesthetically demanding environments. In this study, sandwich‐structured transparent composites were fabricated using glass fiber fabric, plain woven silk fabric, and recycled curtain fabric. The effects of the stacking sequence on the optical and mechanical properties and flexural failure mechanisms of the composites were investigated. Optical performance analysis revealed that when the light‐transmitting composite was configured with recycled curtain fabric as the core layer, silk fabric as the intermediate layers, and glass fiber fabric as the outermost layers, the transmitted light exhibited quasi‐isotropic scattering, resulting in a more uniform and softer visual appearance. Compared with GFRP, G/S/P/S/G composite exhibited 18.9% and 48.3% reductions in light transmittance and average luminance, respectively, while maintaining a stable color rendering index of 93.0 Ra. Three‐point bending tests demonstrated that high‐modulus glass fibers in the outer layers effectively sustained tensile and compressive stresses, while the high toughness and damping capacity of silk fibers inhibited crack propagation. Consequently, G/S/P/S/G composite achieved the highest flexural strength and modulus of 434.4 MPa and 19.0 GPa, respectively, representing increases of 76.9% and 84.5% over S/G/P/G/S composite. Combined camera imaging, acoustic emission, and Micro‐CT analyses revealed dense high‐amplitude signals of 80–100 dB during flexural loading, indicating efficient stress transfer from the matrix to the fibers. Fiber fracture was identified as the dominant damage mechanism, further confirming the superior flexural performance of G/S/P/S/G composite.
ABSTRACT This study examines how five veil interlayer materials fine glass (FG), polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polyetherimide (PEI), and polyimide (PI) affect the mechanical performance of carbon and glass fiber/epoxy composites when placed at two laminate positions (near‐surface, 8/2–1; near‐neutral axis, 8/2–2). Composites were fabricated by Vacuum Assisted Resin Transfer Molding (VARTM). Interlaminar shear strength (ILSS) and flexural properties by three‐point bending tests were evaluated per ASTM D2344 and ASTM D790 while the buckling response was evaluated under axial compression in a purpose‐built free‐clamped fixture and reported as the buckling peak force (BPF) at collapse. Fracture surfaces were examined by scanning electron microscopy (SEM). In carbon fiber composites, PEEK at the 8/2–2 position gave the highest ILSS gain (10.9%) and PEI at 8/2–1 produced the largest flexural strength increase (7.16%). The most pronounced buckling improvements came from FG veils at the near‐neutral axis: 17.33% for carbon and 34.83% for glass fiber systems. Near‐neutral axis placement (8/2–2) generally favored buckling resistance and often improved ILSS though material specific exceptions were observed; surface adjacent placement (8/2–1) was more effective for flexural strength in carbon fiber composites. SEM observations associated the performance gains with interfacial morphology, matrix retention, and mechanical interlocking rather than thickness or density changes alone. Carbon fiber composites showed larger ILSS and flexural strength improvements than glass fiber systems whereas the largest buckling gain was obtained in the glass fiber/FG configuration. These results offer practical guidance for veil selection and laminate positioning in composite interfacial engineering.
ABSTRACT To investigate the coupled effects of interface treatment and casting thickness on the flexural behavior and load‐transfer mechanism of T‐rib GFRP‐mortar composite beams, three‐point bending tests integrating digital image correlation (DIC) and strain measurements were conducted. The results show that interface treatment mainly affects interfacial stress transfer and failure‐mode evolution, whereas casting thickness primarily determines global stiffness and load‐carrying capacity. Increasing the casting thickness increased the peak load by 67% and reduced the corresponding deflection by 86%, while improving interface roughness increased the peak load by 127% and reduced deflection by 56%. Further sectional analysis revealed that increasing casting thickness reduces interfacial shear demand through an increased moment of inertia, whereas enhanced interface roughness improves interfacial shear resistance through stronger mechanical interlocking. Based on this mechanism, a dimensionless coupling criterion Ω was proposed to characterize the balance between interfacial shear resistance and sectional geometric effects, providing a quantitative interpretation of the transition from interface‐dominated to mortar‐dominated failure.
ABSTRACT High‐modulus carbon fiber/epoxy resin (HMCF/EP) composites are promising lightweight materials for critical components in new energy vehicles. However, their practical use is hindered by brittle‐fiber processability, weak interfaces, and insufficient multifunctional integration. Here, a nano‐SiC regulated in situ 3D printing strategy is developed to fabricate sandwich‐structured HMCF/SiC/EP composites. During continuous deposition, SiC nanoparticles are selectively enriched at fiber and EP interfacial gaps. This interfacial enrichment densifies the interphase, suppresses void formation, bridges adjacent fibers, and constructs coupled pathways for thermal transport and electromagnetic attenuation. The optimized composite with 5 wt.% SiC achieves a flexural strength of 784.2 MPa and an interlaminar shear strength of 63.2 MPa, corresponding to improvements of 34.8% and 17%. The in‐plane thermal conductivity reaches 33.65 W/(m K), which is 66% higher than that of the unmodified composite. Meanwhile, the through‐plane thermal conductivity reaches 1.27 W/(m K), showing a remarkable 354% enhancement. The X‐band electromagnetic interference (EMI) shielding effectiveness reaches 56.44 dB, a 241% improvement. These results identify targeted interfacial enrichment as a decisive factor in resolving the structure–function incompatibility of brittle continuous fiber composites beyond indiscriminate filler loading. These results demonstrate a potential interfacial engineering strategy for additive manufacturing of lightweight multifunctional composites with enhanced mechanical, thermal management, and EMI shielding capabilities.
ABSTRACT This study presents a tufting‐enabled through‐thickness reinforcement approach for enhancing the performance of 3D composite lap joints manufactured using resin‐infused and prepreg systems. Similar to stitching and z‐pinning, tufting can introduce local fiber distortion and resin‐rich regions; however, it offers the advantages of single‐sided access and improved manufacturability for complex geometries. A custom‐designed in‐house pin mold was developed to facilitate tufting in dry‐fiber preforms and enable consistent fabrication of composite lap joints. A systematic experimental programme was conducted to evaluate the effect of tuft spacing and off‐edge distance on the mechanical performance of resin‐infused and prepreg lap joints. Mechanical testing under quasi‐static lap shear and three‐point bending conditions demonstrated significant improvements in joint performance. Tufting increased lap shear strength by up to 39% and 37% in resin‐infused and prepreg joints, respectively, while bending strength improved by up to 36% and 20%. Energy absorption analysis showed that tufted joints exhibited approximately 38% higher tensile energy absorption than untufted configurations, while flexural energy absorption increased by approximately 50% and 27% in resin‐infused and prepreg joints, respectively. Microscopic and fractographic analyses revealed modified failure mechanisms characterized by crack bridging, crack arrest, crack branching, and suppressed delamination. These findings demonstrate that tufting is an effective through‐thickness reinforcement strategy for improving the strength, energy absorption, and damage tolerance of composite lap joints while providing a practical manufacturing route for lightweight structural applications.
ABSTRACT This work studied how hybridization between natural and synthetic fibers influences the structural tensile performance, viscoelastic response, and residual stress distribution in fiber–metal laminates (FMLs). Two groups of laminates were produced: (i) fiber‐reinforced polymer (FRP) composites made from carbon, glass, and sisal fibers and (ii) FMLs, including nonhybrid and hybrid configurations with alternating natural and synthetic FRP layers. Tensile properties were determined using digital image correlation (DIC), and failure mechanisms were characterized by x‐ray microtomography. The viscoelastic response was analyzed by multifrequency dynamic mechanical analysis (DMA), while residual stresses were quantified using the layer removal method. The results showed that hybridization did not significantly affect tensile strength but increased strain capacity and energy dissipation due to sisal fibers. DMA indicated higher T g (up to 108°C) and E a (up to 520 kJ mol −1 ) when sisal plies were placed at the laminate core, reflecting enhanced confinement. Residual stress analysis confirmed reduced tensile stresses in aluminum and compressive stresses in FRP layers, leading to a more homogeneous stress state. These findings show that integrating natural fibers improves structural stress distribution and viscoelastic stability while reducing the synthetic fiber content in hybrid composite structures.
ABSTRACT This work developed thermally responsive carbon fiber/epoxy laminates based on PCL@PEBA core‐shell electrospun nanofiber interleaves to improve both interlaminar toughness and post‐damage performance recovery. The core‐shell nanofibers were prepared by coaxial electrospinning, where the low‐melting PCL core was designed to flow into damaged interlaminar regions during low‐temperature thermal treatment, while the PEBA shell helped maintain the fibrous interleaf structure during composite curing and provided an additional thermoplastic phase during higher‐temperature recovery. After being introduced into the interlaminar region of CFRP laminates, the nanofiber interleaf altered crack propagation during delamination and assisted crack filling after damage. The optimized NF‐6.24 laminate increased G IC,ini and G IC,prop by 63.59% and 86.57%, respectively, compared with the control laminate. Its initial ILSS also increased by 22.2%. After cyclic short‐beam shear damage, the NF‐6.24 laminate retained 91.8% and 70.9% of its initial ILSS after the first and second recovery treatments at 65°C, respectively. A subsequent treatment at 150°C increased the ILSS retention to 85.4%, indicating the staged thermal recovery behavior of the PCL@PEBA interleaf. These results suggest that core‐shell electrospun nanofiber interleaves can provide a practical route for combining interlaminar toughening with thermally assisted post‐damage recovery in CFRP/epoxy laminates.
ABSTRACT The present study deals with polypropylene (PP) nanocomposites reinforced with multi‐walled carbon nanotubes (MWCNTs) and reduced graphene oxide (RGO). A constant low filler loading of 1.5% was used individually and in hybrid combinations with different ratios. Twin‐screw extrusion was utilized to fabricate the PP nanocomposites to achieve uniform dispersion. The performance of nanocomposites and their structural property relationships were established via morphological, mechanical, thermal, rheological, and tribological characterizations. Morphological analysis showed better dispersion and formation of a percolated hybrid network at an optimized hybrid filler (MWCNT: RGO) ratio of 80:20. X‐ray diffraction analysis confirmed the retention of the α‐crystalline phase of PP. Differential scanning calorimetry (DSC) analysis revealed increased crystallinity (35.72%), and thermogravimetric analysis (TGA) showed improved thermal stability (degradation temperature of 468.4°C) for the hybrid system. Increased viscosity and strong shear‐thinning behaviors are confirmed through rheological analysis, which indicates the formation of a filler‐induced microstructural network. The hybrid nanocomposite exhibited a 45.3% increase in Young's modulus and a 32.2% increase in tensile strength compared to neat PP. The optimized hybrid system achieved a coefficient of friction of 0.41 ± 0.02 and approximately 97% reduction in wear. The developed material system shows strong potential for advanced lightweight engineering applications.
ABSTRACT Biodegradable PLA/PBS composites reinforced with lignocellulosic fibers remain limited by poor fiber–matrix compatibility, moisture sensitivity, interfacial defects, and wear. The specific knowledge gap addressed here is whether coordinated GPTMS modification of microscale Borassus palm fiber and rice‐husk‐derived nanosilica can establish a hierarchical interphase that improves durability while retaining biodegradability. A 70/30 PLA/PBS blend containing 30 wt% GPTMS‐treated Borassus fiber and 0–2.0 wt% silanized rice‐husk nanosilica was prepared by melt compounding. FTIR, XRD, SEM, and XPS supported surface modification and formation of a silicon‐containing interphase. The 1.5 wt% nanosilica composite exhibited optimal performance, achieving tensile and flexural strengths of 72.60 and 111.60 MPa, respectively, and a storage modulus of 4860 MPa, representing a 64% increase over the untreated fiber composite. It also showed 0.92% void content and a 91.4° water contact angle, while its specific wear rate decreased by 72%. After 180 days of soil burial, it retained 77% of its tensile strength and achieved 46% CO 2 ‐based mineralization. Property deterioration at 2.0 wt% nanosilica identified an optimum loading threshold. These findings demonstrate that coordinated micro‐ and nanoscale interfacial engineering balances mechanical durability, moisture resistance, tribological performance, and biodegradation in waste‐derived PLA/PBS biocomposites.
