Resumen en Inglés:

Abstract To reduce reliance on transplants in cases of disease or trauma caused by accidents, biotechnologies in regenerative medicine and tissue engineering have emerged. The primary goal of tissue engineering is to fabricate devices that mimic the extracellular matrix of injured tissues, thereby facilitating their repair. The synthetic polymer poly(ε-caprolactone) (PCL) is recognized for its favorable mechanical properties, including load-bearing capacity, biocompatibility, and controllable biodegradability. Gelatin, derived from collagen, can replicate the natural extracellular matrix and is rich in amino acids that promote cell adhesion, proliferation, and differentiation, all of which contribute to tissue repair. This study aims to review the fabrication of fibrous scaffolds for tissue engineering, covering process from biomaterial conception to production and application. Conceptual challenges are discussed using gelatin as an example of a natural polymer and PCL as an example of a synthetic polymer.

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Abstract Polymeric composite materials reinforced with carbon fibers are widely used in the aeronautical, automotive, energy, and marine industries due to their excellent mechanical properties and low density. However, these materials are susceptible to defects introduced during manufacturing or service life, requiring reliable non-destructive testing (NDT) methods to ensure quality and structural integrity. Despite the widespread application of NDT , the literature lacks a critical and comparative overview of their limitations, and suitability for composites. This review provides an analysis of the main NDT methods for polymeric composites, including ultrasonic, X-ray, thermography, and microcomputed tomography testing. The study highlights the advantages and challenges of each method, discussing their suitability for different defect types. The findings indicate that combining multiple NDT methods enhances defect detection reliability, addressing the limitations of individual methods. This study provides a reference for researchers and engineers, supporting advancements in material inspection and structural health monitoring.

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Abstract Polypropylene (PP) is a promising insulation material for high-voltage direct current (HVDC) cables due to its electrical, thermal, and chemical stability. However, limitations such as high thermal expansion coefficient, low thermal conductivity, and poor flame retardancy restrict its direct application. This study investigates incorporating nano-scale oxide (MgO) and nitride (AlN) fillers into PP via solution blending to enhance dielectric performance. Nanocomposites with varying filler concentrations were prepared, and their AC breakdown strength and DC conductivity were evaluated. Results show that PP filled with 3 wt% AlN and 3 wt% MgO exhibited improvements in AC breakdown strength 15.4% and 13.82%, respectively compared to pure PP. DC conductivity analysis indicated reduced leakage current for nanocomposites at optimal filler concentrations, supporting their suitability for HVDC insulation. The incorporation of oxide and nitride nano-fillers into PP matrix enhanced electrical insulation characteristics, confirming these nanocomposites' potential for advanced HVDC cable applications

Resumen en Inglés:

Abstract Plastic pollution caused by synthetic polymers is a global concern demanding environmentally friendly alternatives. This study presents the development of a thermoformable bioplastic composed of shrimp-derived chitin, corn starch, sugarcane bagasse, glycerol, and acetic acid, integrated with polyethylene terephthalate (PET) and maleic anhydride as a compatibilizer. The composite underwent mechanical, thermal, and biodegradability assessments. The formulation containing 5% chitin achieved a tensile strength of 0.833 MPa and a density of 2780 Kg/cm3, highlighting its mechanical viability. Under controlled composting conditions, degradation was observed in 120 days. Although the primary polymer matrix consists of petroleum-based PET, the term "bioplastic" is justified by the presence of renewable constituents and proven biodegradability, following the definition by European Bioplastics. This structure supports partial replacement of fossil-derived plastics while promoting sustainable waste management. The study underscores the potential of integrating agro-industrial residues into polymeric systems aimed at contributing to circular economy in material science.

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Abstract This study investigates the mechanical behavior of biobased polyurethane (PU) composites reinforced with chemically treated sisal fibers. Two composites were fabricated: one reinforced with sisal fibers treated in a 10% NaOH solution and the other with fibers treated in a 10% Al(OH)3 solution. The novelty of this work resides in comparing how each treatment affects tensile performance and fracture characteristics. Tensile tests were conducted following ASTM D3039, and fracture surfaces were analyzed by scanning electron microscopy (SEM). The composite reinforced with Al(OH)3-treated fibers exhibited the highest tensile strength (15.14 MPa), followed by the NaOH-treated composite (14.09 MPa), both outperforming neat PU (6.46 MPa). SEM revealed mixed fracture modes, indicating improved fiber–matrix adhesion in treated systems. Results confirm that chemical treatment significantly enhances the mechanical properties of PU–sisal composites. Among the methods studied, Al(OH)3 treatment yielded the most favorable performance, highlighting the potential of treated fibers for sustainable high-performance composites.

Resumen en Inglés:

Abstract This study investigates the surface modification of gelatin films coated on stainless steel using radio-frequency plasma treatment, with a particular emphasis on O2-plasma. Gelatin films cross-linked with glutaraldehyde were subjected to radio frequency plasma modification using N2, O2, and Ar atmospheres. Results showed that O2-plasma was most effective, reducing the water contact angle from 97.3° to 24.9° after 600 seconds due to the introduction of hydrophilic functional groups (–OH, –COOH, –CONH2). Short O2-plasma treatments (10-30 s) significantly decreased bovine serum albumin (BSA) adsorption from 452.5 to 334.4 μg/L (P < 10−4), indicating improved anti-protein adsorption behavior. However, treatments exceeding 60 seconds caused surface cracking and increased BSA adsorption due to higher roughness. The study concludes that controlled short-term O2-plasma modification effectively enhances the surface performance of gelatin-coated stainless steel for biomedical applications.

Resumen en Inglés:

Abstract This study developed active low-density polyethylene (LDPE) packaging incorporating natural antioxidants from wine industry residues and compared them with synthetic antioxidant (BHT). The antioxidant extract (AE), obtained from wine residues, contained 15 phenolic compounds, with catechin (30.51 mg/100g) and epicatechin (22.40 mg/100g) as major flavonoids. Packaging films were produced via extrusion and characterized by FTIR, colorimetry and thermogravimetric analysis. The FE1 active packaging formulation with 12% AE, showed reduced light transmission and improved thermal stability. In peroxide index tests, FE1 preserved sunflower oil below the legal oxidation limit (10 mEq/kg) for up to 5 days, reduced oxidation by 67.90% compared to standard LDPE packaging and 67.71% compared to BHT packaging, maintaining peroxide levels below regulatory limits for a longer duration.The results indicate that incorporating natural antioxidant extracts into LDPE creates active packaging with promising antioxidant properties, with potential for developing innovative solutions through extrusion processes using residues from wine industry.

Resumen en Inglés:

Abstract Mechanical tests previously demonstrated that optimizing the dispersion of micro- and nanoparticulate CaCO3 in polypropylene (PP) composites was successfully achieved through a Design of Experiments (DOE), enabling the identification and guided processing parameters for further evaluation of thermal and barrier properties. The formulation with 1.2 wt% nanofiller exhibited enhanced crystallinity compared to hPP. The incorporation of ~4.0 wt% nanoparticulate CaCO3 increased the Heat Deflection Temperature (HDT) by 12 °C compared to neat homopolymer polypropylene (hPP), and by 3 °C relative to microfilled composites. Oxidation Onset Temperature (OOT) improved with increasing filler content, especially in nanocomposites. A slight reduction in flammability was observed for the composite with ~0.5 wt% nanofiller. Water Vapor Transmission Rate (WVTR) remained mostly unchanged in microcomposites, while a 1.5 wt% microfilled sample showed excellent Oxygen Transmission Rate (OTR) performance. Notably, nanocomposites containing 0.48wt% CaCO3 reduced OTR by 52%, confirming their thermal stability and barrier properties at low filler loadings.

Resumen en Inglés:

Abstract Slow-release urea fertilizer (SRUF) with gradual nitrogen release and high water absorption capacity was synthesized in situ by incorporating urea into a superabsorbent hydrogel matrix of h-collagen-g-poly(acrylic acid). The water absorption capacity of the product was 110 (g/g) times its weight in distilled water at room temperature over 90 minutes. Nitrogen content analysis indicated that the product contained 5.58% nitrogen. The water-holding properties of the product and nitrogen-release behavior in soil and water media were also investigated. The findings indicate that the product exhibits good slow-release properties and excellent water retention capacity. This will efficiently enhance fertilizer utilization and water resource management simultaneously.

Resumen en Inglés:

Abstract The development of functional textiles offers wide-ranging applications, with nanoencapsulation of essential oils emerging as a promising strategy for antimicrobial purposes. This study focused on biodegradable nanoparticles loaded with citronella essential oil (CEO), deposited on cotton textiles using three methods, with or without non-thermal plasma (NTP) treatment. The immersion method achieved the highest CEO content per textile area (5.9 µL cm -2). XPS and FT-IR analyses revealed that NTP treatment enhanced the hydrophilic functional groups through oxidation, as confirmed by contact angle assays and textile mass loss. Despite these changes, NTP treatment did not significantly alter the in vitro release profile of the CEO. Non-treated NTP samples were tested against S. aureus and P. aeruginosa, showing a stronger antibacterial effect against gram-positive S. aureus. These findings highlight the potential of these materials for use as functional antibacterial textiles with promising applications in health and hygiene products.

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Abstract Hybrid laminates are formed by layers of different reinforcements in a matrix to combine distinct properties. Hybridization aims to leverage the advantages of materials, creating a composite with greater mechanical performance and sustainability. This study investigates the replacement of synthetic reinforcements by natural ones. Six composite configurations are analyzed, using glass (G) and jute (J) fabrics with 145 GSM and 245 GSM, respectively, two pure (GGG and JJJ) and four hybrids (GJG, GVG, GGJ and JJG), produced by manual lamination followed by compression. The tensile strength tests (σ), according to ASTM D3039, revealed that the GJG (σ = 87.37 MPa) presented performance closer to the GGG (σ = 89.60 MPa), followed by the GGJ, JJJG, JGJ and JJJ. The resistance is mainly influenced by the sequence of layers, method of manufacture and volumetric fraction of reinforcements. Despite the manufacturing limitations, composites have demonstrated viability for applications with lower structural requirements.

Resumen en Inglés:

Abstract Replacing petroleum-based packaging with biodegradable materials encourages the development of polymers from renewable sources such as sodium alginate, which is biodegradable and abundant in brown algae. The goal of this study was to promote sustainable seedling packaging practices by producing sodium alginate films enriched with urea and glycerol as plasticizers, which were then cross-linked with calcium, fumaric acid, or adipic acid. In this study, both 27 wt% urea and 10 wt% glycerol was used, and the alginate films were prepared by casting with 3 or 10 wt% cross-linker. Thermogravimetric analysis showed that films containing urea exhibited greater thermal stability. FT-IR spectroscopy revealed the formation of partial cross-links between alginate and the cross-linkers, which improved the mechanical and viscoelastic properties. Films cross-linked with calcium ions suggesting that urea does not significantly alter alginate, but contributes to film rigidity, which limits their application for the intended purpose.