Role of Bio-Based and Petroleum-Origin Monomers on the Tailoring of Thermoplastic Elastomer (TPE) Properties and Structure as a Matrix for Composites with Plant-Based and Inorganic Fillers Sandra Paszkiewicz, Zaida Ortega, Izabela Irska, Konrad Walkowiak, Adam Piasecki, et al. Polymers, 2026 This study investigates how natural fillers of different origins and morphologies influence the structural, thermal, rheological, and mechanical properties of thermoplastic elastomers (TPEs). Two series of materials were prepared: one based on a biobased matrix, poly(butylene 2,5-furandicarboxylate)-block-poly(tetramethylene oxide) (PBF-PTMO), and one based on a petroleum-derived matrix, poly(butylene terephthalate)-block-poly(tetramethylene oxide) (PBT-PTMO). Both series incorporated a range of natural modifiers, i.e., lignocellulosic fibers and ground fractions of Arundo donax L., cyanobacterial biomass (Spirulina platensis), and silica-rich mineral dust originating from volcanic stone quarries. The materials were obtained via melt blending, while the reference matrices (neat block copolymers) were synthesized through melt polycondensation. The chemical structure and limiting viscosity number (LVN) of the neat matrices were confirmed, while differential scanning calorimetry (DSC) provided insight into their morphology and phase composition. Scanning electron microscopy (SEM) was employed to evaluate the morphology and distribution of the modifiers within the polymer matrices. To assess how the fillers influenced processing windows and performance, thermogravimetric analysis (TGA), oscillatory rheological measurements, and tensile testing were performed. The results provide insight into structure–property relationships governing natural filler–TPE interactions and support the development of more sustainable elastomeric composites with tailored performance.
Investigating Chemical Modifications in Furan-Based Polyesters Through Experimental and Mathematical Analysis Konrad Walkowiak, Sandra Paszkiewicz, Joanna Aniśko‐Michalak, Marta Safandowska, Artur Rozanski Macromolecular Materials and Engineering, 2026 Poly(trimethylene terephthalate) (PTT) is a widely used engineering polyester, but its petroleum‐derived monomers conflict with current efforts to reduce reliance on fossil feedstocks. Poly(trimethylene 2,5‐furandicarboxylate) (PTF), a fully bio‐based analogue with properties comparable to PTT, is a promising alternative, yet the impact of chemical modifications such as copolymerization remains poorly explored. This work combines mathematical modeling with experimental characterization to predict and validate key thermal and structural properties of bio‐based polyesters and copolyesters. This study underlined the successful synthesis of two series of bio‐based copolymers, i.e. poly(trimethylene terephthalate‐co‐trimethylene glutarate) PTT‐co‐PTG and poly(trimethylene 2,5‐furandicarboxylate‐co‐trimethylene glutarate) (PTF‐co‐PTG) via melt polycondensation. The chemical structure and composition of the copolymers were confirmed with the use of 1 H NMR spectroscopy. Limiting viscosity numbers (LVNs) ranging from 0.643 to 0.759 dL/g were obtained, indicating that the desired values were achieved. The influence of the incorporation of PTG units on thermal properties and morphology was investigated using differential scanning calorimetry (DSC). There were no significant differences in thermal stability and activation energy between the homopolymer and the corresponding copolymers.
Ecofriendly PEF- and PBF-Based Blends with Epoxidized Natural Rubber: Unraveling the Structure–Property Relationship Sandra Paszkiewicz, Konrad Walkowiak, Izabela Irska, Jakub Śmigielski, Elżbieta Piesowicz, et al. Materials, 2025 Two series of environmentally friendly polymer blends of bio-based poly(ethylene 2,5 furanoate) (PEF) and poly(butylene 2,5 furanoate) (PBF) with epoxidized natural rubber (epNR) have been prepared. Both bio-based polyesters were synthesized from dimethyl furan-2,5-dicarboxylate (DMFDC) and 1,2-ethylene glycol (EG) or 1,4-butylene glycol (BG) by a two-stage melt polycondensation process. The miscibility of the components in the blend was assessed using calculations based on Hoy’s method. The chemical interactions, presence of functional groups, miscibility, and possible reactions or cross-linking between polyesters and epNR were analyzed by Fourier Transform Infrared Spectroscopy (FTIR). A significant influence of epNR addition on the melt flow index (MFI), limited viscosity number (LVN), and apparent cross-link density values was also demonstrated. Phase transition temperatures and associated thermal phenomena in polyester/epNR blends were evaluated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Oxidation onset temperature (OOT) tests were performed to obtain valuable information about the thermal-oxidative stability of the blends. Tensile tests revealed that the addition of epNR to PEF increases flexibility but at the same time reduces stiffness and tensile strength, especially at higher contents of epNR. In the case of PBF, a gradual decrease in tensile strength and elastic modulus is observed with increasing epNR content. Additionally, hardness tests showed that the addition of epNR leads to a decrease in hardness for both PEF- and PBF-based compositions.
Sustainable and Eco-Friendly Single- and Multilayer Polyester Foils (Laminates) from Polylactide and Poly(Ethylene 2,5-Furandicarboxylate) Sandra Paszkiewicz, Izabela Irska, Konrad Walkowiak, Filip Włodarczyk, Magdalena Zdanowicz, et al. Molecules, 2025 Packaging materials mainly serve the function of protecting products. The most common representative of this group is poly(ethylene terephthalate) (PET), which is not biodegradable and therefore, its waste might be burdensome to the environment. Thus, this work aims to develop outlines for obtaining polyester-based systems, preferably biobased ones, intended for the packaging industry and their detailed characterization. The obtained multilayer systems based on two biobased thermoplastic polyesters, i.e., poly(ethylene 2,5-furandicarboxylate) (PEF) and the “double green” polylactide (PLA), were subjected to various analyses, i.e., UV-Vis spectrophotometry, microscopic evaluation, tensile tests, differential scanning calorimetry (DSC), oxygen transmission rate (OTR), water absorption tests, surface analyses, and biofilm formation. The best possible arrangement was selected in terms of the packaging industry. It was proven that the elastic modulus was significantly higher for multilayer systems, whilst higher-strength parameters were observed for PLA single foils. Regardless of thickness, PLA and PEF foils exhibit similar absorption values in cold water. Moreover, PEF foils demonstrated significantly better barrier properties towards oxygen gas compared to PLA foils of the same thickness. However, a multilayer system composed of two PLA foils with a single inner PEF foil had an OTR value only slightly higher than that of the PEF foil alone. PEF was also found to be a material that exhibited a limited formation of bacterial biofilm, particularly strains of S. aureus and E. coli. All of the above findings clearly confirm the sensibility of the research topic undertaken in this work on the application of biobased thermoplastic polyesters in the packaging industry.
Biobased polymer nanocomposites prepared by in situ polymerization: comparison between carbon and mineral nanofillers Sandra Paszkiewicz, Konrad Walkowiak, Mateusz Barczewski Journal of Materials Science, 2024 Two series based on poly(propylene 2,5-furandicarboxylate)-block-poly(tetramethylene oxide) (PPF-b-F-PTMO) containing carbon and mineral nanofillers that differ in shape (1D and 2D) were synthesized via in situ polymerization. The influence of the addition of the 1D-type nanoparticle, i.e., carbon nanofibers (CNFs) and halloysite nanotubes (HNTs), and the so-called 2D-type, i.e., graphene nanoplatelets (GNPs) and organoclay (C20A), on the properties of a biobased block copolymer was analyzed. The dispersion of nanoadditives in the nanocomposites was determined using a scanning electron microscope (SEM). The thermal properties were studied employing differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The introduction of nanoparticles increased the crystallinity (Xc) and the mean values of tensile modulus (E) of the bionanocomposites. In turn, one observed that the decrease in the limited viscosity number (LVN) was visible along with incorporating nanoadditives. The synthesized polymer bionanocomposites reveal the mechanical properties of elastomers during mechanical testing. Moreover, the good processability of the obtained materials by injection molding combined with the comprehensive ability to change mechanical and thermal properties of PPF-b-F-PTMO by tailoring the type and content of the nanofillers can indicate their possible applications in packaging, automotive, sports, construction, and many other industries.
Modifications of Furan-Based Polyesters with the Use of Rigid Diols Konrad Walkowiak, Sandra Paszkiewicz Polymers, 2024 The replacement of polymers derived from petrochemical resources has been a prominent area of focus in recent decades. Polymers used in engineering materials must exhibit mechanical strength and stiffness while maintaining performance through a broad temperature range. Most of the polyesters used as engineering materials are based on terephthalic acid (TPA) and its derivatives, which provide necessary rigidity to molecular chains due to an aromatic ring. Bio-based alternatives for TPA-based polyesters that are gaining popularity are the polyesters derived from 2,5-furandicarboxylic acid (FDCA). To broaden applicational possibilities, one effective way to achieve specific properties in targeted applications is to adjust the composition and structure of polymers using advanced polymer chemistry techniques. The incorporation of rigid diols such as isosorbide, 1,4-cyclohexanedimethanol (CHDM), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO) should result in a greater stiffness of the molecular chains. This review extensively explores the effect of incorporating rigid diols on material properties through a review of research articles as well as patents. Moreover, this review mainly focuses on the polyesters and copolyesters synthesized via two-step melt polycondensation and its alterations due to the industrial importance of this method. Innovative synthesis strategies and the resulting material properties are presented.
Influence of flexible segment length on the phase structure and properties of poly(hexamethylene 2,5-furandicarboxylate)-block-biopolytetrahydrofuran copolymers Sandra Paszkiewicz, Konrad Walkowiak, Izabela Irska, Zbigniew Rozwadowski, Jerzy Dryzek Journal of Applied Polymer Science, 2024 Two series of biobased poly(ether‐ester)s comprised of poly(hexamethylene 2,5‐furandicarboxylate) (PHF) as the rigid segments and biopolytetrahydrofuran (pTHF) with different molecular masses (1000 and 2000 g/mol) as the flexible segments were synthesized employing polycondensation in the molten state. The study mainly focuses on comparing these two series in terms of the length of the flexible segment. The content of pTHF segments in the copolymer chains varied from 25 to 75 wt.%. The molecular structure and composition, phase structure, and thermal and mechanical properties were characterized by nuclear magnetic resonance (1H NMR) and Fourier‐transformed infrared (FTIR) spectroscopies, differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and positron annihilation lifetime spectroscopy (PALS). In addition, mechanical performance and thermo‐oxidative and thermal stability have been investigated. Moreover, cyclic tensile properties were studied to evaluate the elastic properties. 1H NMR and FTIR spectroscopies demonstrate that the syntheses were correctly carried out, which made it possible to obtain the desired compositions of the block copolymers with high molecular masses. The decrease in Tm1, Tc1, and XcPHF values was visible, along with the increase in the flexible segment content. Moreover, the characteristic properties measured by PALS and the values of temperatures designated from TGA (inert and oxidizing atmosphere) did not vary between copolymer series PHF‐b‐F‐pTHF1000 and PHF‐b‐F‐pTHF2000. In turn, along with an increase in flexible segment content and the length of the pTHF, the values of tensile modulus, stress at break, and hardness decrease, while the value of elongation at break increases.
