Search Results (405)

Polylactic acid (PLA) is a widely used bio-based polymer, although its application is limited by mechanical brittleness and low thermal resistance. PLA-based biocomposites reinforced with waste materials are gaining attention due to their sustainability, but their durability under degradation conditions remains a key concern. In this work, PLA biocomposites containing 0, 1, and 3% wt. of Olive-stone Biomass Ash (OBA) were manufactured and characterized both (1) after manufacture and (2) after laboratory-accelerated weathering (including UV exposure, heat, and humidity). The results obtained were analyzed to evaluate the influence of ash incorporation on degradation resistance (measured through Carbonyl Indices, CI), mechanical properties (tensile strength), thermal (Thermogravimetric Analysis—Differential Scanning Calorimetry, TGA-DSC), structure (Fourier Transform Infrared Spectroscopy, FT-IR), morphology (Scanning Electron Microscopy, SEM) and appearance (colorimetry and gloss). Key quantitative findings include a 35% reduction in tensile strength for raw PLA after 1000 h weathering exacerbated to 48% and 50% with 1% and 3% OBA incorporation, respectively. Degradation indices showed increased hydroxyl formation, with HI values ranging from 0.38 to 2.80 for PLA, while for biocomposites HI rose up to 5.85 for PLA with 3% OBA. Subsequently, a solid-state reaction was model-fitted from experimental data obtained by means of TGA analysis for determining the kinetic triplet (pre-exponential factor, the activation energy, and the reaction mechanism). Finally, the Acceleration Factor (AF), which combines the effects of radiation, temperature, and humidity to predict long-term material performance, is addressed analytically. Full article

Biocomposites based on natural fibres represent a promising solution for the circular economy. The aim of this study was to develop and characterise a biodegradable composite based on sheep wool from herds raised in the Kyrgyz Republic and polylactide (PLA 4032D). Composite samples with a wool–PLA ratio of 50:50 were fabricated by thermoforming at a temperature of 168 °C for 30 s (n = 10). Mechanical properties tests were performed (PN-EN ISO 604—compression tests), for impact resistance (Charpy method), differential scanning calorimetry (DSC), and measurements of density and thermal conductivity. Biodegradation samples were subjected to enriched soil conditions for 6 weeks in two variants (with and without irrigation). The results showed that the addition of sheep wool to the PLA matrix significantly increased compressive strength (23.56 ± 5.23 MPa) and impact energy absorption (226.2 ± 23.8 kJ/m²) compared to neat PLA. After biodegradation, a 59% reduction in compressive strength was observed while maintaining an increase in fracture energy, suggesting a change in the failure mechanism. The density (0.27 ± 0.02 g/cm³) and the thermal conductivity (0.127 W/m·K) comparable to polymer foams indicate potential for thermal insulation applications. Microscopy and DSC analysis confirmed complete biodegradation under soil conditions. The developed biocomposite from Kyrgyz sheep wool demonstrates the potential for valorisation of local fibrous waste for biodegradable materials with functional insulation properties. Full article

Natural resources, such as wood components (cellulose, hemicellulose, and lignin) and plant oils, have drawn significant interest for the development of polymeric biocomposites. Despite some advantages of soybean hull (SH) and soybean meal (SM), such as high abundance, low cost, and high functionality, both materials lack film-forming properties and mechanical performance and are highly hydrophilic, which makes them incompatible with most polymer matrices. This study demonstrates the suitability of using various ratios of SH and SM in combination with other soy-based derivatives—soy oil-derived polymers—simultaneously in the development of cross-linked biocomposites. For this purpose, we reacted SH or SM with maleic anhydride (via hydroxyl groups) to introduce reactive sites for free-radical polymerization, followed by the bulk polymerization of the maleinized SH and SM in the presence of high-oleic soybean oil-based acrylic monomer (HOSBM). As a result, simultaneous “grafting from” polymerization on the filler surface and formation of the HOSBM homopolymer occur. The synthetic procedure results in a homogeneous distribution of fillers, both modified with soy-derived polymeric chains in the biocomposite matrix (polyHOSBM). In the study, up to 35 wt.% of total SH and SM was incorporated into the biocomposites, further cross-linked via post-polymerization autoxidation of polyHOSBM unsaturated functionalities. The mechanical characterization shows that incorporating 25 wt.% soybean hull leads to an enhanced Young’s modulus and tensile strength in comparison to other investigated biocomposites. Overall, the resulting cross-linked biocomposite films exhibit Young’s modulus in a range of 50–140 MPa, tensile strength of 1–2.9 MPa, and elongation at break of 18–55%. This work demonstrates the potential of the developed synthetic procedure to homogeneously distribute two abundant natural fillers simultaneously in cross-linked biocomposites. Full article

Citrus fruits are among the most important global crops, with annual production exceeding 160 million tons. Processing produces significant waste, mainly peels, seeds, and pulp, which can make up to fifty percent of the fruit’s mass. This review critically examines innovative ways to valorize these byproducts. Recent research shows that peels, seeds, and pulp can be converted into high-value materials, including biocomposites and biomaterials, marking a shift from traditional uses like animal feed and biogas production. Notable innovations include smart packaging, pectin-based wound dressings, and biodegradable polymers for sustainable electronics. Advanced green extraction methods, such as deep eutectic solvents, have achieved extraction yields over 85% for flavonoids. Additionally, multifunctional biorefineries processing citrus and olive residues have increased biogas yields by 38–42%. The review explores emerging applications in nanotechnology, nutraceuticals, biodegradable polymers, and functional coatings, all aligned with principles of circular economy and green chemistry. These advances suggest that citrus waste can play a significant role in sustainability efforts and new market development. The review also discusses barriers to adoption, including scalability challenges, regulatory limits, and consumer acceptance, from both global and regional viewpoints. Full article

There is a growing interest in the application of natural and waste-derived biofillers for reinforcing thermoplastic polymers, as their utilization helps to reduce the carbon footprint and therefore enhances sustainable development. The aim of this study is to synthesize and characterize a biocomposite based on PP reinforced with OS particles derived from biomass in order to reduce plastic shrinkage after injection molding and to assess their viability as environmentally sustainable materials. The addition of OS particles (10 wt.% and 30 wt.%) significantly reduces the crystallinity of the PP, thereby improving its rigidity, its tensile strength, and its thermal stability. DSC analysis and TGA validated superior thermal properties, whereas mechanical and dynamic mechanical assessments indicated augmented stiffness and energy storage capacity with increasing filler content. The utilization of OS waste, abundant in CaCO₃, facilitates a circular economy model, minimizing environmental impact and enhancing waste valorization. The findings underscore the viability of PP/OS biocomposites as sustainable substitutes for traditional mineral-filled polymers in engineering applications. Full article

The growing demand for sustainable materials in construction and sanitation has increased interest in natural fibre-reinforced polymer composites. Rice husk, an abundant agricultural by-product, offers a promising alternative as a reinforcing filler in polypropylene (PP) composites. This study aims to assess the suitability of PP composites reinforced with micronised rice husk particles for application in sanitary components. Two formulations containing 20% and 30% rice husk were developed and characterised. Comprehensive analysis included morphological, thermal, rheological, mechanical, hygroscopic, and tribological testing. Results showed that particles incorporation enhanced thermal stability and crystallinity due to a nucleating effect, with the 30% composite showing higher crystallinity. Thermogravimetric analysis showed that although the T₅% decreased from 374.1 °C for neat PP to 309.2 °C and 296.2 °C for the 20% and 30% composites, respectively, the DTG peak temperatures increased by 15.9 °C and 17.6 °C, indicating a delayed main decomposition stage of PP matrix and enhanced overall thermal stability. Rheological behaviour revealed increased viscosity and pseudoplasticity at higher particle content Mechanical characterisation showed an increase in Young’s modulus from 1021 MPa for neat PP to 1065 MPa (+4%) and 1125 MPa (+10%) for PP_Rice_20% and PP_Rice_30%, respectively. In contrast, the nominal strain at break dropped sharply from 238% (PP) to 30% (PP_Rice_20%) and 16% (PP_Rice_30%). Shrinkage decreased from 1.31% (PP) to approximately 1.05% in both composites, indicating improved dimensional stability. However, water absorption rose from 0.015% (PP) to 0.111% (PP_Rice_20%) and 0.144% (PP_Rice_30%), accompanied by an increase in surface roughness (Sa from 0.34 µm to 0.78 µm and 1.06 µm, respectively). The composite with 20% rice husk demonstrated better filler dispersion, reduced water uptake, and smoother surfaces, making it more suitable for injection-moulded components intended for use in humid environments. Overall, the study supports the use of agricultural residues in high-performance biocomposites, contributing to circular economy strategies and the development of more sustainable polymer-based materials for technical applications. Full article

A promising strategy for pancreatic cancer therapy involves developing nanocarriers capable of simultaneously delivering various antitumor substances with diverse physicochemical properties, often resulting in synergistic effects. In the present work, novel biocomposites were developed using amphiphilic N-vinylpyrrolidone polymer incorporating bortezomib (BTZ) and modified with either the DR5-selective TRAIL cytokine (DR5-B) or its fusion with the iRGD effector peptide (DR5-B-iRGD), resulting in AmphPVP-BTZ-DR5-B and AmphPVP-BTZ-DR5-B-iRGD formulations. The release of BTZ was most extensive at acidic pH 5.6, mimicking endolysosomal compartments, while at near-neutral pH 7.4 and alkaline pH 8.2 the release was slower and less complete, indicating a smart pH-responsive behavior suitable for triggered release in the tumor microenvironment. Both AmphPVP-BTZ-DR5-B and AmphPVP-BTZ-DR5-B-iRGD significantly inhibited the growth of pancreatic adenocarcinoma cell lines PANC-1, BxPC-3, and MIA PaCa-2 and induced more rapid internalization of the DR5 receptor in MIA PaCa-2 cells than unmodified particles and free DR5-B or DR5-B-iRGD. Importantly, AmphPVP-BTZ-DR5-B-iRGD exhibited a more pronounced DR5 internalization rate and cytotoxic effect than AmphPVP-BTZ-DR5-B owing to the presence of fusion protein with internalizing iRGD peptide. Both biocomposites induced cell death via the apoptotic pathway while exhibiting minimal cytotoxic effects on healthy cells. Therefore, biocomposites incorporating BTZ and functionalized with DR5-selective TRAIL variants DR5-B or DR5-B-iRGD represent a promising avenue for future studies in pancreatic cancer animal models. Full article

Biopolymers such as chitosan and gelatin are emerging as leading alternatives to traditional plastic packaging due to their enhanced capabilities and biodegradability. Blends of chitosan and gelatin combine chitosan’s antimicrobial and film-forming properties with gelatin’s biocompatibility and flexibility. These biomaterials possess tunable mechanical, biological, and physicochemical properties, making them suitable for biomedical, pharmaceutical, food packaging, environmental, and agricultural applications. This study investigates the preparation and characterization of composite biopolymer films based on chitosan and gelatin, incorporating coffee silverskin extract (SSE) as a natural bioactive additive. Coffee silverskin, a by-product of coffee roasting, is rich in phenolic compounds and demonstrates notable antioxidant potential. The objective of this work was to enhance the antioxidant, mechanical, and physicochemical properties of chitosan–gelatin films through the integration of SSE. The biocomposite materials were prepared using solvent casting, followed by extensive characterization techniques, including Fourier-transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, and UV–Vis spectroscopy. Additionally, color measurements, mechanical properties, and physicochemical properties were assessed. The transmission rates of oxygen and water vapor were also examined, along with the antioxidant activity of the films. The inclusion of coffee silverskin extract facilitated intermolecular interactions between the polymer chains, resulting in improved structural integrity. Furthermore, films containing CSE exhibited enhanced antioxidant activity (up to 28.43% DPPH radical scavenging activity), as well as improved water vapor barrier properties and mechanical strength compared to the pure chitosan–gelatin. The films showed a yellowish appearance. There was a noticeable reduction in the rate of oxygen transmission through the films as well. These results highlight the potential of coffee silverskin as a sustainable source of functional compounds for the development of bioactive materials suited for biodegradable packaging and biomedical applications. Full article

The aim of the work was to obtain poly(butylene succinate)—a PBS biocomposite material with an addition of natural sodium montmorillonite (Na-MMT) modified with two selected terpenes: pinene (P) and limonene (L) or their mixture (PL)—and examine their physico-chemical, rheological, and antiviral properties. Na-MMT was effectively hydrophobized and intercalated (confirmed with FTIR, TGA, and XRD analysis results) with the terpenes via the solventless method. The materials were obtained via extrusion, and the films were formed using thermo-compression molding. The addition of the fillers slightly increased mechanical properties, but barrier properties towards oxygen and water vapor were significantly improved (OTR from 52 to 28 cm³/m²∙24 h and WVTR 21 to 11 g/m²∙24 h for PBS and composite, respectively) without alteration of polymer morphology (SEM, XRD, FTIR) or thermal and thermomechanical properties, despite high filler content (10 wt%) in the polymer matrix. Surface contact angle values of PBS/M, PBS/M-L, and PBS/M-PL exhibited antiviral properties and were tested using Φ6 bacteriophage. The composites can be used for materials in medical and food packaging applications. Full article

Background/Objectives: Regenerating critical-sized bone defects is a significant clinical challenge. Autogenous bone grafts are the gold standard but have limitations, including donor site morbidity. As an alternative, this study introduces a novel biocomposite combining an ethyl cyanoacrylate (ECA) polymer with Hancornia speciosa (Hs) latex. The ECA acts as a scaffold and delivery vehicle for the latex, which contains phytochemicals with known angiogenic properties. Methods: We created 5 mm critical-sized calvarial defects in 36 Wistar rats, which were divided into four experimental groups. Bone regeneration was evaluated at 30, 60, and 90 days using micro-computed tomography (micro-CT) for morphometric analysis and hematoxylin and eosin staining for histology. Results: The composite-treated group (Hs+ECA) showed significantly higher bone volume (57.2; IQR: 56.7–61.2) than the control (53.9; IQR: 49.4–56.4) and ECA-only (48.4; IQR: 47.2–59.9) groups at 90 days (p < 0.05). By day 60, the bone volume in the Hs+ECA group was statistically similar (p > 0.05) to that of the autogenous bone group. Histological analysis revealed an organized repair process with neoangiogenesis observed only in the Hs+ECA group, confirming the material’s strong bioactivity. Conclusions: The Hs+ECA composite is a promising biomaterial that acts as an effective delivery system for the bioactive components of the latex. The induced angiogenesis was critical to its regenerative success. This cost-effective material warrants further investigation for clinical applications in regenerative dentistry. Full article

In this study, aiming to develop novel biocomposites that offer competitive properties while retaining their renewable and biodegradable characteristics, a biodegradable polymer matrix (Mater-Bi^® HF51L2) was reinforced with natural particles extracted from the culm and leaf of Cymbopogon flexuosus (lemongrass). Particles (<500 µm) were incorporated at 10 and 20 wt.% via twin-screw extrusion followed by compression moulding. Morphological analysis via SEM revealed distinct structural differences between culm- and leaf-derived particles, with the latter exhibiting smoother surfaces, higher density, and better dispersion in the matrix, resulting in lower void content. Quasi-static mechanical tests showed increased stiffness with filler content, particularly for leaf-based composites. This material, at 20 wt.% filler loadings, enhanced the tensile and flexural moduli of the neat Mater-Bi approximately three and two times, respectively, a result attributed to enhanced interfacial adhesion. Rheological measurements (rotational and capillary) indicated significant increases in complex viscosity, particularly for leaf-filled systems, confirming restricted polymer chain mobility and good matrix–filler interaction. Dynamic mechanical thermal tests (DMTA) results showed an increased storage modulus and a shift in glass transition temperature (T_g) for all biocomposites in comparison to Mater-Bi matrix. Specifically, the neat matrix had a T_g of −28 °C, which increased to −24 °C and −18 °C for the 20 wt.% culm-reinforced and leaf-reinforced biocomposites, respectively. Overall, the leaf-derived particles demonstrated superior reinforcing potential, effectively improving the mechanical, rheological, and thermal properties of Mater-Bi-based biocomposites. Full article

Arthroscopic shoulder surgery has undergone significant evolution over the past decades, particularly in the materials used for suture anchors. The transition from metallic to bioabsorbable polymer anchors has revolutionized soft tissue-to-bone repair procedures, offering distinct advantages in terms of biocompatibility, imaging compatibility, and reduced complications. This comprehensive review examines the current state-of-the-art in anchor polymers used in arthroscopic shoulder surgery and their biocomposite formulations. Additionally, we explore the role of biostable polymers and emerging technologies in anchor design. The review synthesizes clinical outcomes, degradation kinetics, biocompatibility profiles, and mechanical properties of various anchor polymer systems. We also discuss the challenges associated with each material type, including osteolysis, cyst formation, premature degradation, and osseointegration. Recent advances in biocomposite anchors demonstrate promising solutions to address these limitations, offering controlled degradation rates and enhanced osteoconductivity. This review provides clinicians and researchers with a comprehensive understanding of anchor polymer technologies, their clinical applications, and future directions in arthroscopic shoulder surgery. Nevertheless, potential publication bias and heterogeneity among studies should be considered when interpreting comparative data. Full article

Thermoplastic starch (TPS) is a biodegradable polymer from renewable sources, but its limited mechanical and thermal properties restrict wider industrial use compared to petroleum-based plastics. In this study, TPS-based biocomposites were developed and optimized by incorporating agricultural and mineral Residues: coffee husks (CH), potassium feldspar (PF), and Bahia Beige marble (BB) as reinforcements. Mechanical, thermal, and morphological characterizations were carried out, and a simplex–lattice mixture design was applied to optimize the formulations. The 70/20/5/5 (TPS/CH/PF/BB, wt.%) composition achieved the highest tensile strength (2.0 MPa) and elastic modulus (70.2 MPa), while the 90/0/5/5 formulation showed superior impact resistance. FTIR and SEM analyses confirmed effective filler dispersion and strong matrix–filler interactions. Scheffé polynomial models (R² > 87%) accurately predicted performance, highlighting the reliability of the statistical approach. From a sustainability perspective, this work demonstrates that upcycling coffee husks and mineral residues into TPS-based biocomposites contributes to waste reduction, landfill diversion, and the development of cost-effective biodegradable materials. The proposed systems offer potential for eco-friendly packaging and agricultural applications, reducing dependence on fossil-based plastics and mitigating the environmental footprint of polymer industries. Statistical optimization further enhances efficiency by minimizing experimental waste. Moreover, this research supports circular economy strategies and provides scalable, sustainable solutions for waste valorization. Full article

This study focuses on the development, characterization, and numerical simulation of novel composite materials based on natural vegetable fibers for applications in civil engineering. Three different bio-based composites were formulated using Alfa plant fibers, wood waste, and an equal mixture of both (50% Alfa, 50% wood), with polyvinyl acetate (PVAc), a non-polluting polymer matrix, as the binder. The performance of these composites is strongly influenced by the fiber morphology, structural characteristics, and the nature of the matrix. Thus, understanding and optimizing these parameters is crucial for tailoring materials to meet specific design requirements. The experimental approach began with the morphological and structural characterization of the raw and treated fibers, followed by the evaluation of the thermal a properties of the resulting composites. Furthermore, thermal conductivity simulations were performed using COMSOL Multiphysics to validate the experimental results and gain deeper insights into heat transfer behavior within the composites. A comparative analysis with conventional synthetic insulation materials revealed that the developed bio-composites offer competitive thermal performance while being more environmentally sustainable. These findings highlight the potential of Alfa and wood waste fibers as effective, eco-friendly alternatives for thermal insulation in building applications. Full article

Starch is a promising alternative to petroleum-based polymers due to its biodegradability and renewable nature. However, its widespread use in non-food applications raises ethical concerns. Mango kernels, a major byproduct of mango processing, represent an abundant yet underutilized starch source. However, conventional starch extraction requires costly purification steps with significant environmental impact. This study explores the development of extruded biocomposites, using corn starch and mango kernel flour (MKF) as a more sustainable alternative. The influence of lignin, extractives, amylose, and amylopectin content on the material properties was assessed. MKF was obtained by removing both tegument and endocarp from the mango kernels, grinding them in a colloidal mill, and finally drying the ground kernels. The resulting flour was blended with corn starch, processed in an internal mixer, and injection-molded. The composites were characterized through mechanical testing, water absorption analysis, colorimetry, and UV absorption assays. Notably, the composite containing ~20% MKF exhibited mechanical properties comparable to commercial polyethylene (PE-PB 208), with a tensile strength of 9.53 MPa and a Young’s modulus of 241.41 MPa. Additionally, MKF enhanced UVA protection. These findings suggest that mango kernel flour can partially replace starch in the production of injection-molded biopolymers, offering a more sustainable approach to biodegradable plastic development. Full article