Search the digital library catalog

Abstract: This study presents the synthesis and characterization of a series of multiblock copolymers, poly(ethylene 2,5-furandicarboxylate)-poly(ε-caprolactone) (PEF-PCL), created through a combination of the two-step melt polycondensation method and ring opening polymerization, as sustainable alternatives to fossil-based plastics. The structural confirmation of these block copolymers was achieved through Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), ensuring the successful integration of PEF and PCL segments. X-ray Photoelectron Spectroscopy (XPS) was employed for chemical bonding and quantitative analysis, providing insights into the distribution and compatibility of the copolymer components. Differential Scanning Calorimetry (DSC) analysis revealed a single glass transition temperature (Tg), indicating the effective plasticizing effect of PCL on PEF, which enhances the flexibility of the copolymers. X-ray Diffraction (XRD) studies highlight the complex relationship between PCL content and crystallization in PEF-PCL block copolymers, emphasizing the need to balance crystallinity and mechanical properties for optimal material performance. Broadband Dielectric Spectroscopy (BDS) confirmed excellent distribution of PEF-PCL without phase separation, which is vital for maintaining consistent material properties. Mechanical properties were evaluated using Nanoindentation testing, demonstrating the potential of these copolymers as flexible packaging materials due to their enhanced mechanical strength and flexibility. The study concludes that PEF-PCL block copolymers are promising candidates for sustainable packaging solutions, combining environmental benefits with desirable material properties.
Keywords: poly(ethylene furanoate), poly(ε-caprolactone), block copolymers, thermal properties, molecular dynamics, crystallinity, mechanical properties, flexible packaging
Published in DKUM: 13.03.2025; Views: 0; Downloads: 6
Full text (4,73 MB)
This document has many files! More...

Abstract: In recent years, bio-based poly(ethylene furanoate) has gained the attention of packaging industries owing to its remarkable properties as a promising alternative to fossil-based polymers. It is necessary to synthesize high-molecular-weight polymers using effective and straightforward techniques for their commercialization. In this present work, poly(ethylene 2,5-furan dicarboxylate) (PEF) was produced with a high molecular weight of 0.43 dL/g using 2,5-furan dicarboxylic acid (FDCA) or its derivative Dimethyl-2,5-Furan dicarboxylate (DMFD), followed by solid-state polymerization (SSP) conducted at different temperatures and reaction times. The intrinsic viscosity ([η]), carboxyl end-group concentration (–COOH), and thermal properties of the produced polyesters were evaluated using differential scanning calorimetry (DSC). The results indicated that the SSP process improved the melting temperature and crystallinity of both the PEF samples as the reaction times and temperatures increased, as corroborated by DSC and X-ray diffraction (XRD) analyses. Additionally, both intrinsic viscosity and number-average molecular weight saw an increase with longer SSP durations and higher temperatures, while the concentration of carboxyl end groups decreased, aligning with expectations. The overall results indicate that PEF (DMFD) samples exhibited a significant increase in crystallization and molecular weight, attributed to their lower degree of crystallinity and their monomer’s high purity.
Keywords: bio-based polymers, 2, 5-furan dicarboxylic acid, dimethyl 2, 5-furan dicarboxylate, poly(ethylene 2, 5-furan dicarboxylate), poly(ethylene furanoate), solid state polymerization, thermal properties
Published in DKUM: 10.03.2025; Views: 0; Downloads: 7
Full text (4,07 MB)
This document has many files! More...

Abstract: This work aimed to produce bio-based poly(ethylene furanoate) (PEF) with a high molecular weight using 2,5-furan dicarboxylic acid (FDCA) or its derivative dimethyl 2,5-furan dicarboxylate (DMFD), targeting food packaging applications. The effect of monomer type, molar ratios, catalyst, polycondensation time, and temperature on synthesized samples’ intrinsic viscosities and color intensity was evaluated. It was found that FDCA is more effective than DMFD in producing PEF with higher molecular weight. A sum of complementary techniques was employed to study the structure– properties relationships of the prepared PEF samples, both in amorphous and semicrystalline states. The amorphous samples exhibited an increase in glass transition temperature of 82–87 ◦C, and annealed samples displayed a decrease in crystallinity with increasing intrinsic viscosity, as analyzed by differential scanning calorimetry and X-ray diffraction. Dielectric spectroscopy showed moderate local and segmental dynamics and high ionic conductivity for the 2,5-FDCA-based samples. The spherulite size and nuclei density of samples improved with increased melt crystallization and viscosity, respectively. The hydrophilicity and oxygen permeability of the samples were reduced with increased rigidity and molecular weight. The nanoindentation test showed that the hardness and elastic modulus of amorphous and annealed samples is higher at low viscosities due to high intermolecular interactions and degree of crystallinity.
Keywords: bio-based polymers, poly(ethylene furanoate), polycondensation, thermal properties, mechanical properties, oxygen transmission rates
Published in DKUM: 13.02.2025; Views: 0; Downloads: 3
Full text (13,28 MB)
This document has many files! More...

Keywords: biobased polymers, poly(ethylene furanoate), nanoparticles, nanocomposites, antimicrobial properties
Published in DKUM: 10.04.2024; Views: 160; Downloads: 19
Full text (4,47 MB)
This document has many files! More...

Abstract: Poly(ethylene furanoate) (PEF)-based nanocomposites were fabricated with silver (Ag) and titanium dioxide (TiO2) nanoparticles by the in-situ polymerization method. The importance of this research work is to extend the usage of PEF-based nanocomposites with improved material properties. The PEF-Ag and PEF-TiO2 nanocomposites showed a significant improvement in color concentration, as determined by the color colorimeter. Scanning electron microscopy (SEM) photographs revealed the appearance of small aggregates on the surface of nanocomposites. According to crystallinity investigations, neat PEF and nanocomposites exhibit crystalline fraction between 0–6%, whereas annealed samples showed a degree of crystallinity value above 25%. Combining the structural and molecular dynamics observations from broadband dielectric spectroscopy (BDS) measurements found strong interactions between polymer chains and nanoparticles. Contact angle results exhibited a decrease in the wetting angle of nanocomposites compared to neat PEF. Finally, antimicrobial studies have been conducted, reporting a significant rise in inhibition of over 15% for both nanocomposite films against gram-positive and gram-negative bacteria. From the overall results, the synthesized PEF-based nanocomposites with enhanced thermal and antimicrobial properties may be optimized and utilized for the secondary packaging (unintended food-contact) materials.
Keywords: active agents, antimicrobial studies, biobased polymers, crystallinity, poly(ethylene 2, 5-furandicarboxylate)
Published in DKUM: 03.04.2024; Views: 214; Downloads: 20
Full text (3,13 MB)
This document has many files! More...