Iskanje po katalogu digitalne knjižnice

Opis: Polylactide (PLA) is the most widely used biopolymer, but its poor ductility and scarce gas barrier properties limit its applications in the packaging field. In this work, for the first time, the properties of PLA solvent-cast films are improved by the addition of a second biopolymer, i.e., poly(decamethylene 2,5-furandicarboxylate) (PDeF), added in a weight fraction of 10 wt%, and a carbon-based nanofiller, i.e., reduced graphene oxide (rGO), added in concentrations of 0.25–2 phr. PLA and PDeF are immiscible, as evidenced by scanning electron microscopy (SEM) and Fouriertransform infrared (FTIR) spectroscopy, with PDeF spheroidal domains showing poor adhesion to PLA. The addition of 0.25 phr of rGO, which preferentially segregates in the PDeF domains, makes them smaller and considerably rougher and improves the interfacial interaction. Differential scanning calorimetry (DSC) confirms the immiscibility of the two polymer phases and highlights that rGO enhances the crystallinity of both polymer phases (especially of PDeF). Thermogravimetric analysis (TGA) highlights the positive impact of rGO and PDeF on the thermal degradation resistance of PLA. Quasi-static tensile tests evidence that adding 10 wt% of PDeF and a small fraction of rGO (0.25 phr) to PLA considerably enhances the strain at break, which raises from 5.3% of neat PLA to 10.0% by adding 10 wt% of PDeF, up to 75.8% by adding also 0.25 phr of rGO, thereby highlighting the compatibilizing role of rGO on this blend. On the other hand, a further increase in rGO concentration decreases the strain at break due to agglomeration but enhances the mechanical stiffness and strength up to an rGO concentration of 1 phr. Overall, these results highlight the positive and synergistic contribution of PDeF and rGO in enhancing the thermomechanical properties of PLA, and the resulting nanocomposites are promising for packaging applications.
Ključne besede: nanocomposites, reduced graphene oxide, poly(decamethylene 2, 5-furandicarboxylate), furanoate polyesters, polylactic acid, compatibilization
Objavljeno v DKUM: 20.03.2025; Ogledov: 0; Prenosov: 1
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Opis: Furanoate polyesters are an extremely promising new class of materials for packaging applications, particularly furanoate-based nanocomposites, which have gained a high interest level in research and development in both academia and industries. The monomers utilised for the synthesis of furanoate-based polyesters were derived from lignocellulosic biomass, which is essential for both eco-friendliness and sustainability. Also, these polyesters have a lower carbon footprint compared to fossil-based plastics, contributing to greenhouse gas reduction. The furanoate-based nanocomposites exhibit enhanced performance characteristics, such as high thermal stability, excellent mechanical strength, superior barrier resistance, and good bacteriostatic rate, making them suitable for a wide range of industrial applications, especially for food-packaging applications. This paper reviews the recent trends in the synthesis routes of monomers, such as the various catalytic activities involved in the oxidation of 5(hydroxymethyl)furfural (HMF) into 2,5-furandicarboxylic acid (FDCA) and its ester, dimethyl furan-2,5-dicarboxylate (DMFD). In addition, this review explores the fabrication of different furanoate-based nanocomposites prepared by in situ polymerization, by melt mixing or solvent evaporation methods, and by using different types of nanoparticles to enhance the overall material properties of the resulting nanocomposites. Emphasis was given to presenting the effect of these nanoparticles on the furanoate polyester’s properties.
Ključne besede: 2, 5-furandicarboxylic acid, dimethyl furan-2, 5-dicarboxylat, furanoate polyesters, furanoate nanocomposites, thermal properties, mechanical properties, antibacterial properties, sustainable packaging
Objavljeno v DKUM: 10.03.2025; Ogledov: 0; Prenosov: 5
Celotno besedilo (4,54 MB)
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Ključne besede: biobased polymers, poly(ethylene furanoate), nanoparticles, nanocomposites, antimicrobial properties
Objavljeno v DKUM: 10.04.2024; Ogledov: 160; Prenosov: 19
Celotno besedilo (4,47 MB)
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Ključne besede: tissue engineering, nanocomposites, 3D printing, bioactive coatings, applications
Objavljeno v DKUM: 02.04.2024; Ogledov: 249; Prenosov: 17
Celotno besedilo (3,36 MB)
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Opis: Three different and very small amounts of alumina (0.2, 0.3 and 0.5 wt. %) in two sizes (approx. 25 and 100 nm) were used to enhance the wear characteristics of ZA-27 alloy-based nanocomposites. Production was realised through mechanical alloying in pre-processing and compocasting processes. Wear tests were under lubricated sliding conditions on a block-on-disc tribometer, at two sliding speeds (0.25 and 1 m/s), two normal loads (40 and 100 N) and a sliding distance of 1000 m. Experimental results were analysed by applying the response surface methodology (RSM) and a suitable mathematical model for the wear rate of tested nanocomposites was developed. Appropriate wear maps were constructed and the wear mechanism is discussed in this paper. The accuracy of the prediction was evaluated with the use of an artificial neural network (ANN). The architecture of the used ANN was 4-5-1 and the obtained overall regression coefficient was 0.98729. The comparison of the predicting methods showed that ANN is more efficient in predicting wear.
Ključne besede: ZA-27 alloy, Al2O3 nanoparticles, nanocomposites, wear, response surface methodology, artificial neural network
Objavljeno v DKUM: 20.03.2024; Ogledov: 239; Prenosov: 13
Celotno besedilo (14,10 MB)
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