Search Results (231)

In response to the growing demand for environmentally friendly and sustainable yet functional technical textiles, this research developed a spun-bonded nonwoven from the biodegradable thermoplastic starch-based biopolymer BIOPLAST^®, incorporating fruit extracts as natural sources of polyphenolic compounds and surface-active additives. Extracts from Vaccinium myrtillus L. and Sambucus nigra L. were applied onto a nonwoven’s surface via aerographic spraying using a water/ethanol system. The resulting materials were characterized in terms of morphology, physicochemical and mechanical behavior, surface characteristics, and stability under accelerated ageing and hydrolytic conditions. Treatment with the extracts increased the tensile strength by roughly 38% and elongation at break by about 50%, and it changed the surface from hydrophobic (contact angle of 115°) to hydrophilic, with contact angles of 83° for the blueberry-modified nonwoven and 55° for the elderberry-modified nonwoven. The modified nonwovens also showed sustained release of polyphenolic compounds over 72 h, which is beneficial for biomedical, healthcare, and cosmetic applications, where short-term use, controlled release of active compounds, and bioactivity are more important than long-term durability. Overall, the results indicate that BIOPLAST^®-based spun-bonded nonwovens can serve as fully bio-based carriers for fruit extracts in MedTech-related technical textiles, offering a straightforward way to introduce additional functionality into biodegradable nonwovens. Full article

Thermoplastic starch (TPS) nanocomposites with unprecedentedly high loadings of up to 15 wt.% of the nano-clays Laponite (LAP; a synthetic product capable of good dispersion in suitable media) or Montmorillonite (MMT; modified with dialkyldimethylammonium chloride) were prepared by means of our new, two-step TPS preparation protocol. In both the TPS/LAP and TPS/MMT composites, we achieved perfect dispersion and extensive exfoliation of the nano-clays, resulting in pronounced improvements in mechanical performance (modulus increased up to one order of magnitude) and in excellent gas-barrier properties (extremely small permeabilities for O₂, CO₂, and even H₂). MMT, owing to its larger platelet size and to the formation of partially exfoliated multi-layer structures, generated a percolating filler network that provided particularly strong reinforcement, especially at 15 wt.% loading. LAP, though more completely exfoliated, generated a somewhat smaller mechanical reinforcement, but it more strongly increased processing viscosity due to its high specific surface area, which generated highly stable physical crosslinking that persisted even at processing temperatures of T ≥ 120 °C. Efficient matrix–filler interactions were confirmed by thermogravimetric analysis, where the better-exfoliated LAP generated a higher stabilization. The combination of strong mechanical reinforcement with outstanding gas-barrier properties makes the TPS/MMT and TPS/LAP nanocomposites attractive for food-packaging applications, where their natural origin, non-toxicity, bio-degradability, and abundance of nanocomposite components are an additional bonus. Full article

Biodegradable starch-based films often suffer from insufficient mechanical strength, which limits their practical applications. To enhance film performance, this study optimized the preparation of composite thermoplastic starch (CTPS) films composed of corn starch, sorbitol, whey protein isolate (WPI), and gallic acid (GA). The optimized formulation—0.074 g/mL corn starch, 47.5% sorbitol, 5.6% WPI, and 2.0 mg/mL GA—yielded films with a tensile strength of 3.11 ± 0.31 MPa and an elongation at break of 43.35 ± 0.69%, achieving a desirable balance between flexibility and strength. Mechanistic investigations using in situ Fourier-transform infrared spectroscopy (FTIR), low-field nuclear magnetic resonance (LF-NMR), confocal laser scanning microscopy (CLSM), and molecular docking revealed a ternary interaction system among starch, WPI, and GA. These components primarily interacted through hydrogen bonding and van der Waals forces. Such non-covalent interactions enhanced the short-range molecular ordering of the starch matrix, stabilized the secondary structure of WPI, and facilitated water redistribution during film formation. The resulting interaction network among starch, proteins, and polyphenols significantly improved the mechanical properties and antioxidant capacity of the CTPS films. Full article

In this study, the authors focus on optimizing the processing parameters for the fabrication of biodegradable polymer filaments intended for subsequent 3D printing of biomedical structures and implants. Following extrusion and additive manufacturing, the produced materials underwent a comprehensive evaluation that included mechanical, microbiological, biofilm formation, and electron microscopy analyses. The complexity of these tests aimed to determine the potential of the developed materials for biomedical applications, particularly in the field of scaffold fabrication. At the initial stage, three types of filaments (technical designations 111, 145, and 146) were produced using Fused Filament Fabrication (FFF) technology. These filaments were based on a PLA/PHB matrix with varying types and concentrations of plasticizers. Standardized destructive tensile and compressive mechanical tests were conducted using an MTS Insight 1 kN testing system equipped with an Instron 2620-601 extensometer. Among the tested samples, the filament labeled 111, composed of PLA/PHB thermoplastic starch and a plasticizer, exhibited the most favorable mechanical performance, with a Young’s modulus of elasticity of 4.63 MPa for 100% infill. The filament labeled 146 had a Young’s modulus of elasticity of 4.53 MPa for 100% infill and the material labeled 145 had a Young’s modulus of elasticity of 1.45 MPa for 100% infill. Microbiological assessments were performed to evaluate the capacity of bacteria and fungi to colonize the material surfaces. During bacterial activity assessment, we observed biofilm formation on the examined sample surfaces of each material from the smooth and rough sides. The colony-forming units (CFUs) increased directly with the exposure time. For all samples from each material, the Log10 (CFU) value reached above 9.41 during 72 h of incubation for the activity of each type of bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans). Scanning electron microscopy provided insight into the surface quality of the material and revealed its local quality and purity. Surface defects were eliminated by this method. Overall, the results indicate that the designed biodegradable filaments, especially formulation 111, have promising properties for the development of scaffolds intended for hard tissue replacement and could also be suitable for regenerative applications in the future after achieving the desired biological properties. Full article

The use of biodegradable polymers in slow-release NPK fertilizers is gaining prominence for reducing overdosing, minimizing nutrient loss, and enhancing efficiency. This study prepared modified and unmodified thermoplastic starch (TPS) systems via extrusion, incorporating collagen and potassium phosphate. Controlled-release nutrient systems utilizing nitrogen from an organic source were developed and characterized. The materials were characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), contact angle measurements, and biodegradability in the soil. The biodegradability of the polymeric matrix was evaluated through mass loss, with up to 78.9% degradation observed after 60 days for TPS-based systems containing collagen. Structural modifications in the TPS matrix led to changes in crystallinity and hydrophilicity, which directly influenced degradation rates. The nutrient release effect was assessed by monitoring the growth of chili pepper seedlings over 15 days. Seedlings grown in soil containing polymeric systems with 20% collagen or 6.2% urea reached average heights between 5.2 and 7.8 cm, compared to 5.0 cm for the unmodified TPS and 0 cm in treatments with pure urea, which caused seedling mortality. The polymeric systems containing collagen exhibited superior performance as a sustainable nitrogen source, ensuring a slower and more controlled release while yielding positive outcomes for early plant development. Full article

The mechanical, thermal, physicochemical and structural properties of a thermoplastic cassava starch obtained by a twin-screw extrusion process were evaluated, using glycerol and isosorbide as plasticizers at different concentrations (30, 35 and 40% by weight) and storage times (1, 15 and 30 days) under controlled conditions of relative humidity of 47 ± 2% and temperature of 25 ± 2 °C. The results obtained show a decrease in tensile strength and modulus of elasticity and an increase in elongation in the initial measurements, suggesting that, in both cases, a plasticization phenomenon via absorption of humidity predominated in short times, while at prolonged times, a rigidification of the material occurred due to the generation of a retrogradation process. Likewise, a higher tensile strength and lower elongation were found in the materials plasticized with isosorbide. Finally, it was observed that the retrogradation phenomenon was more evident in the thermoplastic starch samples made with glycerol, and that the starches plasticized with isosorbide had lower moisture absorption, higher crystallinity and a predominantly Eh-type crystalline pattern, related to greater stability over time. Full article

In this work, microfibrillated cellulose (MFC) from ash branch wood was used as reinforcement in a thermoplastic starch matrix to develop environmentally friendly materials. Pulp fibers and MFCs were characterized by SEM, TEM, and FTIR. Corn starch biofilms were prepared via casting, formulating eight biofilms with 5 and 10 wt% of MFC. Also, extracts of Muicle and Hibiscus were added to incorporate antibacterial properties. The biofilms were evaluated for mechanical, thermal, and antibacterial properties. Also, properties such as color, opacity, morphology, electrical conductivity, contact angle, and solubility, among others, were evaluated. The reinforced biofilms were homogeneous, dimensionally stable, and transparent with slight color changes. MFC incorporation enhanced hydrogen bonding, which increased the ultimate tensile strength from 11.2 MPa to approximately 19–21 MPa and the Young’s modulus from 809 MPa to 1034–1192 MPa. The presence of MFC also reduced solubility from 48.7% to 38.7–39.8% and decreased water vapor permeability by about 20–23% in biofilms with 10 wt% MFC. Gas barrier properties and the glass transition temperature depended on extract type and fiber content, indicating greater rigidity. The use of ash-based MFC encourages the implementation of circular economy strategies and the development of sustainable biocomposites. Full article

C footprint is a feature used to search the integral life cycle of a product to predict its environmental impact. The packaging industry is changing rapidly to the production of biodegradable products to mitigate the negative environmental consequences of the use of single-use packages. It is thought that biodegradable packages should be more sustainable than traditional plastics due to the sources of the raw materials used to produce them, but this is not always true and depends on the issues considered, the methodology, and the scale analyzed. Limited research includes case studies from developing countries where waste management is less efficient and where the environmental impacts of single-use packaging can be more significant. This paper evaluates the C footprint of bags and dishes made from traditional or local biodegradable sources in an Amazonian settlement of Colombia, such as thermoplastic cassava starch and powdered plantain leaves, to evaluate the impact of locally made biodegradable packaging vs. imported petrochemical ones. Results show that using local raw materials and in situ production reduces the C footprint of biodegradable packages, considering that the energy source for production and transport are important contributors to the C footprint beyond the raw materials used, with ratios that can be between 0.1 and 7 times more kg CO₂ eq generated per functional unit. Full article

In this study, poly(butylene adipate-co-terephthalate) (PBAT), starch, glycerol, and grape seed extract (GSE) were blended and extruded to fabricate PBAT/thermoplastic starch(TPS)/GSE active films by blow molding. The interaction between GSE and TPS primarily occurred through hydrogen bonding, with little interaction observed with PBAT. The oxygen barrier property of the film was improved by the incorporation of GSE into the films, whereas the mechanical properties slightly decreased. The PBAT/TPS/GSE films had excellent UV blocking properties imparted by PBAT and visible light blocking properties endowed by GSE. The films containing GSE offered antimicrobial activity against Escherichia coli and Staphylococcus aureus by delaying bacterial growth. Also, the GSE-added films exhibited antioxidant activity with strong dose dependence due to the free radical scavenging ability of polyphenolic compounds in GSE. The shelf life of peanut butter packaged with the PBAT/TPS/GSE-5 film was expected to exceed 300 days, which was approximately twice that of LDPE film packaging. The proposed active films had good material properties, functional activities, and excellent ability to prolong the shelf life of peanut butter. Full article

This study aims to develop a modified starch with menthol (M) or sulfobetaine (S) using 1,6-hexamethyl diisocyanate (HMDI) as a linker to create biodegradable antibacterial materials for active packaging applications. The modification of potato starch is performed in a two-step reaction. First, the starch modifiers are synthesized through an equimolar reaction between HMDI and menthol or the sulfobetaine precursor. Next, the synthesized HMDI derivative is dissolved in a bio-based solvent (methyl-THF) with starch and K₂CO₃ (1:1 weight ratio) to chemically modify the starch. The chemical and thermal properties of the modified starch are analyzed. Starch films containing 25 wt.% glycerol and low amounts (0.5, 1, and 3% wt.) of M- or S-modified starch were successfully produced by extrusion. Although most film properties remain similar to the control, adding 3% of S-modified starch resulted in a 149% increase in Elastic Modulus and a 29% decrease in water vapor permeability. Additionally, just 0.5 wt.% of either M- or S-modified starch effectively inhibits S. aureus growth, indicating its potential as a bioactive compound for active packaging. 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

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

Although the strain hardening phenomenon has been studied in different types of materials, there are only a few such reports regarding flexible food packaging. To address this issue, nanoclay-reinforced and control starch-based films were subjected to sequential and weekly tension and the rheological index, defined as the ratio of the tensile strength observed under weekly to that under consecutive elongation, was measured. The results showed that the values of the rheological index were >1, implying a strain hardening effect that was more notable when nanoclay was added and when the stress duration was increased. Additionally, a cumulative damage test was conducted, involving the gradual increase of two factors in each step: the percentage of the elongation level and the duration of each step. The data were fitted to a linear model, describing the correlation between the ln failure time (μ) and the tensile strength (X), μ = 6.021 − 0.478 X. This model enabled the prediction of the failure probability and the hazard rate of the films that were studied. In addition, from the survival of the units in the initial steps of the cumulative damage experiment, it can be hypothesized that the elongation of the units under low stress levels, for prolonged periods of time, exhibits rheological memory properties, which leads to an increase in their mechanical strength. Full article

Biodegradable composites obtained by reinforcing thermoplastic starch (TPS) with lignocellulosic fibers show great potential, but their strong sensitivity to water still limits practical applications. Among possible reinforcements, Helianthus tuberosus (topinambur) represents an underutilized agricultural residue that has been scarcely explored in this context. In this work, we demonstrate for the first time that topinambur fiber can improve the water vapor barrier properties of cassava starch films, while also providing a detailed analysis of sorption isotherms and the humidity-dependent relationship between surface roughness and contact angle, aspects rarely addressed in previous studies. SEM revealed uniform fiber dispersion and integration. Water sorption kinetics showed that fiber addition reduces both hydration and sorption time constant, indicating lower water affinity and greater water mobility. Water sorption isotherms confirmed that fiber incorporation significantly alters overall hydration and water–matrix interactions, revealing reduced effective water solubility in films. Water vapor permeability also decreased with fiber addition, mainly due to decreased water solubility, rather than changes in water diffusivity. While fiber addition enhanced surface-water repellency across all humidity levels, roughness exhibited a humidity-dependent response FTIR analysis confirmed fiber–matrix compatibility and suggested new hydrogen bonding. Overall, these findings identify topinambur fiber as a novel reinforcement for designing biodegradable films with improved humidity resistance for agroecological 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