Search Results (4,987)

This study analyzes the effect of two bioactive additives—caffeic acid and natamycin (Natamax^®)—on the properties of poly(butylene succinate) (PBS) in the context of applications in biodegradable active packaging. Materials containing 1, 3, and 5 wt.% of the additives were prepared by melt blending and characterized in terms of density, rheological behavior (MFR), mechanical properties, thermal stability (TGA), and thermal behavior and crystallization (DSC). Caffeic acid strongly reduced the melt viscosity (reflected by a significant increase in MFR) and, at higher concentrations, led to material stiffening and increased strength at the expense of a pronounced reduction in deformability. Natamycin exhibited a milder rheological effect; at 1 wt.% it simultaneously improved strength and elastic modulus, whereas at higher loadings it deteriorated mechanical performance due to structural effects. Both additives were thermally compatible with PBS; caffeic acid introduced an additional degradation step, while Natamax^® did not significantly alter the degradation mechanism. The results indicate that both the type and concentration of the additive govern the structure–property–function relationships and enable the design of PBS-based packaging materials with controlled performance and functional characteristics. Full article

Growing demand for sustainable materials has intensified research into eco-friendly alternatives to conventional and synthetic leathers. Traditional bovine leather and its chromium-tanning process heavily contribute to water pollution, toxic waste generation, and carbon emissions, while synthetic leather derived from Polyvinyl Chloride (PVC) and polyurethane (PU) presents challenges related to fossil fuel dependence and non-biodegradability. This review explores bio-based and sustainable leather substitutes that are made of plants, microbial cellulose, and mycelium fungi. Plant-based leather substitutes such as Vegea^®, Desserto^®, and Piñatex^® use agricultural waste products to create durable, partially biodegradable composites. Microbial cellulose from kombucha fermentation offers material with good physical and aesthetic properties. Mycelium leather, derived from fungal biomass, demonstrates potential for scalable and low-impact production. Comparative analyses of mechanical and physical properties show that mycelium composites are approaching industrial standards, though challenges remain regarding tensile strength, water resistance, and process standardization. Despite current limitations, bio-based leathers, particularly mycelium composites, offer a promising way toward circular material innovation and carbon-neutral manufacturing in fashion, automotive, design and other industries. Full article

Effective management of acute, complex, and chronic wounds requires constructs that simultaneously support tissue repair and provide sustained infection control. Biologic-derived materials, despite their regenerative potential, are limited by insufficient long-term antibacterial activity and susceptibility to enzymatic degradation. To overcome these limitations, a fully absorbable synthetic matrix composed of electrospun composite fibers functionalized with polyhexamethylene biguanide (PHMB) (hereafter, PHMB Matrix) was developed to mimic extracellular matrix architecture while enabling durable antibacterial performance. Quantitative assessment per AATCC 100 demonstrated robust broad-spectrum efficacy (>99.99% reduction) against six clinically relevant Gram-positive and Gram-negative pathogens, with potency retained after 15 months of real-time aging. The matrix’s interconnected fibrous architecture enables a controlled, biphasic PHMB release coordinated with biodegradation, sustaining antibacterial protection throughout a 28-day healing period. In porcine full-thickness wound models, the PHMB Matrix achieved 63.53% ± 12.0% wound area reduction by Day 22, demonstrating accelerated mid-phase healing compared to an antibacterial collagen control (p < 0.05 on Day 22), with both treatments achieving comparable near-complete closure by Day 28. Pharmacokinetic analysis confirmed localized drug enrichment with negligible systemic exposure. These findings establish the PHMB-functionalized synthetic matrix as a safe, effective, fully absorbable alternative to biologic-derived materials for soft tissue repair, offering sustained antibacterial efficacy and a favorable safety profile. Full article

The development of bio-based functional materials through the upcycling of agri-food residues represents a sustainable strategy to reduce environmental impact and promote circular economy. This study achieved valorization by combining two tomato by-products: peels exhausted after supercritical fluid extraction and harvest residues mainly composed of stems and field wastes. Polyphenol-rich extract (TPPf) was obtained from peels through ultrasound-assisted maceration and solid-phase extraction, while cellulose from tomato harvest residues (THRs) was converted into carboxymethyl cellulose (THR-CMC, degree of substitution 0.76), as confirmed by structural analyses. Functional bioplastic films were prepared by solvent casting THR-CMC, plasticized with glycerol, and enriched with different TPPf concentrations (0–100 mg/100 mL). Increasing TPPf content enhanced mechanical strength and UV-blocking efficiency, while moderate loading improved moisture barrier properties. The films exhibited notable antioxidant activity (ABTS, DPPH assays) and biodegradability, demonstrating biofunctional performance suitable for food packaging. This integrated valorization strategy highlights the potential of combining agricultural and industrial tomato residues to develop sustainable, biodegradable, and active packaging materials, supporting waste reduction and circular bioeconomy objectives. Full article

Biodegradable nanocomposite materials possessing self-healing behavior are emerging as an attractive option of being used in advanced mechatronic systems. The current study is focused on a thorough examination of the micromechanical properties of graphene–reinforced polylactic acid (PLA)/polycaprolactone (PCL) composite samples, followed by estimation of their self-healing behavior upon heating. Polymer blend–based nanocomposite materials were prepared using the green and reliable in terms of good nanofiller dispersion melt extrusion method. 3D printed nanocomposite specimens with impeccable flatness were subjected to fine microscratch testing by applying a constant force experimental mode. The surface resistance of the three-component polymer materials against the lateral movement of the stylus fulfilling the scratch and the impact of the dual-phase PLA/PCL ratio on the nanocomposite mechanical performance were estimated by calculation of the coefficient of friction (COF = F_x/F_z). COF values in the range of 0.8–1.4 indicated excellent nanocomposite resilience against scratch. Creating a heterogeneous polymer system that combines phase-separated soft and hard domains with close melt and glass transition temperatures, respectively, may facilitate the physical flow of macromolecular chains into voids or free volume areas. This aspect can be critical in the achievement of thermally–induced self-healing properties of the composite material. Scanning electron microscopy (SEM) imaging of the microscratches, made before and after Joule heating of the polymer samples, revealed a significant degree of surface recovery and a sensible reduction in the width of the adjusted scratch grooves. Full article

Agro-industrial waste-derived materials are promising candidates for short-cycle packaging applications. Here, we report a proof-of-concept for biodegradable biocomposites formulated with cassava residue (CR), sugarcane bagasse (SCB), and bacterial cellulose (BC) produced by symbiotic fermentation (SCOBY). This approach addresses the mechanical limitations typically associated with cassava starch-based matrices by introducing natural reinforcements to improve structural integrity and cohesion. A set of formulations with varying CR/BC/SCB ratios was processed and assessed through tensile and flexural testing, elongation at break, thermal analysis, and water-related behavior (sorption, absorption, and contact angle). Among the evaluated blends, formulation F1 (80% CR, 5% BC, 15% SCB) delivered the best overall balance between performance and moldability, achieving a tensile strength of 11.97 MPa and showing good dimensional stability. Biodegradability was confirmed by composting, reaching 72.74% mass loss after 84 days. Overall, BC incorporation improved matrix cohesion and enabled control of mechanical integrity and wettability in the blends, as highlighted for F1 (tensile strength 11.97 MPa; peak force 560.32 N; contact angle 65°; water absorption rate, WAR, 58.68%; sorption time 5.4 s). Given the abundance of sugarcane and cassava residues in Northeast Brazil, this low-complexity route leverages locally available feedstocks to add value to regional waste streams and support the partial replacement of synthetic polymers. Full article

Biodegradable zinc (Zn) has attracted increasing interest as a material for temporary implants, primarily due to its moderate degradation kinetics. In recent years, additive manufacturing of Zn alloys using the laser powder bed fusion method (L-PBF) has shown promising results. Compared to as-cast Zn alloys, it offers preferable customized solutions for patient-specific temporary biomedical implants. Due to the novelty of these printed degradable biomaterials and due to reported cytotoxic effects of Zn alloys, this study investigates additively manufactured ZnAgCu, ZnAgCuMn, and ZnAgCuTi alloys, both in as-printed and post-processed conditions, with a focus on L929 and SAOS-2 biocompatibility. In this work, we demonstrate that the increased porosity and therefore larger surface areas compared to polished Zn-alloy samples affect their biocompatibility. Minimal to no cell proliferation was observed on and near the Zn-alloy test plates after 24 h. Undiluted extracts from as-cast Zn and L-PBF-manufactured plates were initially cytotoxic to SAOS-2 cells. However, as passivation proceeded, cytocompatibility was significantly increased from day 3 onward. Zn²⁺ ion release peaked at 24 h and declined significantly from day 2 to day 10. Compared to the other Zn alloys, ZnAgCuMn exhibited the lowest cytocompatibility. Most intriguingly, 3-month surfaces exhibited reduced cytocompatibility to osteoblasts compared to freshly polished samples. The observed in vitro cytotoxicity motivates further investigation of as-printed and post-processed L-PBF-manufactured Zn alloys, aiming to develop novel surface modification strategies to mitigate the initial ion burst responsible for reduced cytocompatibility and to adjust and tailor the overall degradation kinetics to physiologically tolerable levels tailored to the intended clinical application. Full article

Aquifers are increasingly threatened by the uncontrolled release of non-biodegradable chemicals derived from anthropogenic activities. The development of new remediation strategies has therefore focused on the use of sustainable adsorbent materials, including synthetic organic hydrogels and biochars produced from agricultural residues. In this study, the removal of two organic pollutants, the herbicide Metribuzin (MEB) and Propyl Paraben (PrP), from aqueous environments was investigated using negatively charged hydrogels and biochars derived from lime peel, respectively. Propyl Paraben (PrP) and Metribuzin (MEB) are among the pollutants frequently found in aquatic environments, and the effective and sustainable removal approaches remain under investigation. The hydrogels studied (P(DMAM co-ANax)) were based on sodium methacrylate (ANa) copolymerized with N,N-dimethylacrylamide (DMAM). The adsorption performance of the materials was evaluated through UV-Visible absorption spectrophotometry and High-Performance Liquid Chromatography (HPLC). The results of this study showed that the hydrogel achieved a very high removal efficiency for MEB, which was over 80% for the concentration range studied (max $Q_e$ = 0.386 mg/g). Similar behavior was also recorded for the biochar from lime peel, which achieved almost complete removal of PrP (~100%) at the lowest concentrations of the contaminant (5 mg/L) and maintained high removal rates (78%) at 10 mg/L (max $Q_e$ = 0.187 mg/g). These results demonstrate the potential of both types of materials to efficiently remove the studied contaminants from water, indicating their suitability for environmental remediation applications. This work contributes to the development of cost-effective and eco-friendly adsorbents for the treatment of water pollution caused by emerging organic compounds. Full article

The global demand for sustainable and effective food preservation techniques has spurred significant interest in biodegradable packaging materials, with chitosan films emerging as a promising solution for extending the shelf life of highly perishable seafood products such as shrimp. This review systematically summarizes recent advances in the development, characterization, and functional enhancement of chitosan-based films for shrimp. Chitosan, derived from chitin, has inherent antimicrobial, antioxidant, and biodegradable properties, making it an ideal candidate for eco-friendly packaging. The key physicochemical and functional properties of chitosan films, including their mechanical strength, barrier performance, and structural characteristics, are discussed. Functional enhancements, such as the incorporation of natural bioactive compounds (e.g., essential oils and plant extracts) and nanofillers, have been shown to significantly improve the antimicrobial efficacy, oxygen and water vapor barrier properties, and mechanical stability of films. A critical aspect of this progress is the synergistic effect achieved by combining chitosan with other antimicrobials, which broadens the spectrum of activity against various bacterial strains and enhances overall preservation efficacy. Recent studies have demonstrated that functionalized chitosan coatings effectively inhibit microbial growth, retard lipid oxidation, and maintain sensory and nutritional quality during refrigerated storage of shrimp. In addition, this review evaluates current limitations related to large-scale production, cost-effectiveness, and regulatory approval for commercial applications. Overall, chitosan-based preservation systems represent a promising approach for sustainable seafood packaging. Future research may focus on industrial scalability, multifunctional film design, and integration with smart/active packaging technologies. Full article

The growing pollution caused by plastics with slow degradation kinetics is demanding the search for biodegradable alternatives. Starch-based films are a promising option, but their practical application may be limited by their potential susceptibility to rapid ultraviolet (UV) exposure degradation. This study evaluates the effect of prolonged UV-C irradiation (254 nm, 168 h) on plasticizer-free films derived from the starch of an Ecuadorian potato Solanum tuberosum (Chola variety). Films formulated at 3% and 5% (w/v) starch were characterized before and after UV exposure. The analysis includes the evaluation of optical, mechanical, and physicochemical properties, along with Fourier Transform Infrared spectroscopy (FTIR) and atomic force microscopy (AFM) for nanoscale surface inspection. UV irradiation increased the opacity of the films but reduced slightly their tensile strength, elongation at break, moisture content, and total soluble matter. In contrast, the elastic modulus remained relatively high. FTIR analysis revealed no significant formation of new functional groups. AFM measurements indicated that irradiation caused only minor nanoscale alterations in the same film regions. These alterations were more pronounced in films with higher starch concentrations. The results demonstrate that UV-C exposure induces minor structural adjustments in plasticizer-free starch films derived from the Chola variety, without compromising their fundamental integrity. Consequently, this work advances the understanding of the environmental stability of these films and supports their potential application as sustainable materials, even in conditions involving UV exposure. Full article

Alginate–chitosan composites are widely used bio-based materials due to their biocompatibility, biodegradability, and relatively simple processing methods. By combining the complementary properties of alginate and chitosan, these systems offer adjustable mechanical characteristics suitable for applications such as tissue engineering, wound healing, drug delivery, and sustainable packaging. However, although many studies report improved mechanical properties, the link between structural design and mechanical behavior is often discussed within specific applications rather than examined in a broader context. This review focuses on how polymer ratio, charge balance, crosslinking strategy, reinforcement approach, and processing conditions influence the mechanical properties of alginate–chitosan composites. Instead of considering these factors separately, the available studies are discussed in terms of how the internal structure of the composite affects stiffness, strength, deformability, and stability. This review brings together findings from various fields to highlight shared structure–mechanical relationships and to provide guidance for designing alginate–chitosan composites with specific mechanical properties. Full article

The growing interest in bio-based and biodegradable polymer composites reinforced with agricultural waste reflects global efforts to reduce dependence on fossil resources and improve the sustainability of materials. However, biocomposites are not necessarily more sustainable, and their environmental performance requires careful life cycle assessment (LCA). This review critically analyses recent LCA studies of biodegradable biocomposites reinforced with agricultural waste, focusing on methodological choices, data quality, results and limitations. A systematic literature review was conducted using the Scopus database, focusing on studies from the last five years. Selected studies were examined using a structure consistent with ISO 14040, with defined data extraction categories and key questions. The analysis shows that although biocomposites often demonstrate advantages in terms of climate change and fossil resource depletion compared to traditional materials, the results vary significantly depending on the definition of the functional unit, geographical context, processing pathways, and data assumptions. Limitations include reliance on laboratory data, uncertainties, incomplete system boundaries, inconsistent allocation methods, and limited end-of-life (EoL) modelling. Overall, the review highlights the need for improved data quality, performance-based functional units, geographically representative inventories, and more standardised LCA practices to ensure meaningful comparisons and support the sustainable development of biocomposites. Full article

Sustainable alternatives to synthetic polymer-based sanitary napkins are essential to reduce the environmental impact and health concerns. This study presents a method for using water hyacinth (Eichhornia crassipes), an invasive aquatic weed, as biomass to produce biodegradable absorbent material for sanitary pads. Water hyacinth fibers were treated with an alkaline solution and incorporated into the absorbent core. Morphological, chemical, structural, functional, microbiological, and biodegradability evaluations were then conducted systematically. Scanning electron microscopy showed that non-cellulosic components were successfully removed, producing a rougher surface topology and enhanced fiber interactions. Fourier-transform infrared spectroscopy confirmed structural changes in cellulose after treatment. Additionally, X-ray diffraction showed that the crystallinity index increased from 53.21% in untreated fibers to 62.56% in treated fibers, indicating improved order and stability. The developed absorbent sanitary pad showed rapid fluid uptake, absorbing 10 mL within three seconds while maintaining a skin-compatible neutral pH of 6.87, as specified in Indian Standard IS 5405:1980. Microbial contamination remained low, with a total bacterial count of 360 CFU/g, no yeast or mold at ≤1 CFU/g, and no presence of Staphylococcus aureus. Soil burial tests showed 70% biodegradability at 40 days and approximately 95% at 60 days, indicating high biodegradability. These findings demonstrate the potential of water hyacinth as an inexpensive and environmentally friendly material for manufacturing hygienic sanitary pads, highlighting the sustainability benefits of valorizing invasive biomass and reducing reliance on synthetic polymers. Full article

The environmental persistence of post-consumer plastics remains a critical challenge due to their chemical stability, the presence of additives, and prior environmental weathering. This study evaluates the partial biodegradation and chemical transformation of post-consumer low-density polyethylene (LDPE) and expanded polystyrene (EPS) by Tenebrio molitor larvae under uncontrolled environmental conditions. Four diets were tested, including LDPE+S and EPS+S (polymers supplemented with wheat bran), to assess the influence of a co-substrate on larval performance and polymer transformation. Fourier-transform infrared spectroscopy (FTIR) revealed the emergence of oxygen-containing functional groups (–OH and C=O) in the frass, which were absent or negligible in pristine materials, indicating oxidative modification of the polymer matrix. Gel permeation chromatography (GPC) revealed pronounced reductions in number-average molecular weight (Mn) and increased polydispersity for EPS-derived fractions, consistent with heterogeneous chain scission and partial depolymerization. For LDPE, GPC evidenced the formation of THF-soluble, low-molecular-weight polymer-derived fragments, indicating fragmentation despite the inability to quantify pristine LDPE due to its insolubility in the mobile phase. Gas chromatography–mass spectrometry (GC–MS) identified aromatic hydrocarbons, phthalate esters, organosiloxanes, and fatty acid derivatives, reflecting both degradation intermediates and migrated additives from post-consumer plastics. Together, these results provide integrated evidence that Tenebrio molitor can induce chemical transformation of post-consumer LDPE and EPS under non-controlled environmental conditions, offering mechanistic insight into a biologically mediated degradation pathway that is directly relevant to realistic plastic waste scenarios. Full article

Linear alkylbenzene (LAB) is the main raw material used to make biodegradable detergents, and its production process is based on aromatic alkylation. HY zeolites that have undergone controlled dealumination and desilication have led industrial standards amongst solid acid catalysts because of their controllable acidity and hierarchical pore structure. Coke formation in such systems can assume a dual role, which is dependent on its condition. Though the over-deposition is known to cause deactivation by blocking the micropores, Bronsted acid-site masking, and diffusion collapse, the low-level deposition could also be done to increase the monoalkylate selectivity by the pore mouth catalysis, steric modulation, and selective suppression of secondary alkylation pathways. The critical review is done on the structural-kinetic interaction that determines the coke evolution in HY-based catalysts. In order to moderate the acid-site density and enhance hydrothermal stability, dealumination (Si/Al optimization of about 2.5 to 30–100) occurs, but to reduce deep-pore coke formation, desilication (interconnected mesopores) is created. The bimodal porosity and regulated acidity are found to be synergistic, as hierarchical HY zeolites produced through successive cycles of steam and alkaline treatments not only show LAB selectivity in excess of 90% but also exhibit much longer catalyst lifetimes. Quantitative research on the beneficial coke regime revealed that it was composed of about 36 wt% hydrogen-rich species, which were localized at the pore mouths, hence enhancing monoalkylation selectivity by 15–40%. Beyond a critical transition window (e.g., 8–12 wt.%), coke formation to condensed polyaromatic and graphitic products leads to fast deactivated coke formation, which is due to percolation limits and transport-controlled kinetics. More advanced techniques of characterization of the coke, e.g., temperature-programmed oxidation (TPO), ²⁷Al MAAS NMR, and UV-Raman spectroscopy, indicate how the coke is changed to highly structured graphitic deposits of high oxidation activation energy. Activity recovery of 85–98% is obtained in regeneration processes, including controlled oxidative calcination, microwave-based and plasma-based processes, and thermal management protocols, and it would be determined by the chemistry of the coke, its spatial distribution, and the regeneration protocols. This paper has developed a mechanistic coke control system by cross-tuning the acidity and development of an effective pore network, which led to a sustainable aromatic alkylation reaction with minimal activity loss, high selectivity, and long life. Full article