Search Results (418)

This narrative review examines contemporary applications of polymeric materials in dentistry from 2020 to 2025, spanning prosthodontics, restorative dentistry, orthodontics, endodontics, implantology, diagnostics, and emerging technologies. We searched PubMed, Scopus, Web of Science, and Embase for peer reviewed English language articles and synthesized evidence on polymer classes, processing routes, mechanical and chemical behavior, and clinical performance. Approximately 116 articles were included. Polymers remain central to clinical practice: poly methyl methacrylate (PMMA) is still widely used for dentures, high performance systems such as polyether ether ketone (PEEK) are expanding framework and implant-related indications, and resin composites and adhesives continue to evolve through nanofillers and bioactive formulations aimed at improved durability and reduced secondary caries. Thermoplastic polyurethane and copolyester systems drive clear aligner therapy, while polymer-based obturation materials and fiber-reinforced posts support endodontic rehabilitation. Additive manufacturing and computer aided design computer aided manufacturing (CAD CAM) enable customized prostheses and surgical guides, and sustainability trends are accelerating interest in biodegradable or recyclable dental polymers. Across domains, evidence remains heterogeneous and clinical translation depends on balancing strength, esthetics, biocompatibility, aging behavior, and workflow constraints. Full article

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a biodegradable polyester considered for food packaging, though its mechanical and barrier limitations pose challenges. This study assessed PHBV/TiO₂ nanocomposites for packaging applications. Differential scanning calorimetry revealed reduced crystallinity and lower melting points with an increase in TiO₂ content. Thermal stability improved at 1% and 3% TiO₂, raising onset temperatures to 283 °C and 284 °C, respectively. Scanning electron microscopy and FTIR confirmed uniform nanoparticle dispersion without agglomeration. Tensile tests showed decreasing strength and modulus from 1% to 7% TiO₂, with peak elongation at 3%, whereas viscosity behavior declined with higher nanoparticle loading. Low portions of nanoparticles (1% and 3%) induced the improvement in barrier properties against oxygen and water vapor. The highest biodegradation rate occurred at 7% TiO₂. Overall, the nanocomposites’ properties tend to deteriorate with the addition of higher portions of TiO₂. Thus, despite some improvements, the nanocomposites did not deliver consistent, multi-property enhancements to justify use in food packaging. Key metrics like sealability and appearance were not evaluated. Future research should explore surface-treated TiO₂, alternative fillers, compatibilizers, and optimized processing, alongside standardized safety assessments for food-contact applications. Full article

Isosorbide-based aliphatic polyesters are a promising class of biodegradable polymers for biomedical applications, representing an attractive alternative to poly(α-hydroxy acids). Derived from the bio-based bicyclic diol, they combine structural rigidity, tunable hydrophilicity, and enhanced biocompatibility, making them suitable for drug delivery and sustainable medical devices. In this study, we developed novel in situ forming implant (ISFI) formulations composed of poly(isosorbide sebacate) (PISEB) and dimethyl isosorbide (DMI), and evaluated their applicability for local delivery of doxycycline hyclate (DOXY), minocycline hydrochloride (MIN), and/or eugenol (EUG). Basic characteristics of new ISFI formulations were investigated. Rheological analysis demonstrated that the liquid formulations exhibited shear-thinning behavior, which is advantageous for ISFI systems. However, the MIN-loaded formulation exhibited excessively rapid drug release, with a pronounced initial burst (86.4 ± 5.9%) within 24 h, whereas the DOXY-loaded system showed a lower burst of 41.1 ± 5.9% over the same period. The effect of EUG addition on depot morphology and antibiotic release profiles was also assessed. In vitro drug release studies demonstrated that EUG reduced the release rate of both antibiotics, increasing and prolonging their antibacterial activity. Eugenol co-released with antibiotics also reduced the pro-inflammatory effect of the released antibiotic doses by more than tenfold. Full article

Poly(hydroxyalkanoates) (PHAs) have garnered significant attention due to their biodegradable and biocompatible properties, making them promising alternatives to conventional petroleum-based plastics. As microbial-derived polyesters, PHAs offer a sustainable solution to plastic waste accumulation and microplastics because they can be produced from renewable resources, including food-related waste. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a copolymer in the PHA family, exhibits improved mechanical flexibility and thermal properties compared to poly(3-hydroxybutyrate), thereby broadening its potential applications. In this work, eight samples of PHBV, including those made from food waste and municipal waste streams, were studied by solid-state NMR. Information obtained includes the copolymer composition, chemical shifts due to crystalline lattices, crystallinity, and polymer chain mobility. The composition matches the results from the fatty acid feed and solution NMR analysis. The samples appear to be about 62–70% crystalline. No significant differences in mobility are observed from NMR relaxation data. These results indicate that PHBV materials generated from different food-related waste sources, despite their compositional differences, possess similar crystallinity and molecular mobility, suggesting their suitability as biobased semi-crystalline plastics. Full article

Polybutylene adipate terephthalate (PBAT), a flexible biodegradable polyester, has gained widespread use in packaging applications due to its ability to degrade under controlled conditions, producing non-toxic substances. While this property makes PBAT particularly attractive for the development of transient electronic devices, this potential application remains unexplored. To address this research gap, we developed PBAT-based composites and modified their electrical properties through CO₂ laser functionalization. Although laser treatment of neat PBAT primarily resulted in material ablation, the incorporation of lignin and silica-based fillers enabled the formation of electrically conductive pathways. Among the various fillers tested, dealkaline lignin (DEALK) and glass fibers (GFs) provided the optimal combination of electrical conductivity, mechanical properties, and processability. Characterization techniques (electrical measurements, optical microscopy, SEM, EDX, and TGA) highlighted that by optimizing laser treatment and the filler concentration, it is possible to produce conductive tracks with remarkably low sheet resistance. Hybrid composites containing 10–15 wt% of GF and 20–25 wt% of lignin demonstrated the best electrical performance with values as low as 3.5 Ω/sq, which were further reduced to 1.72 Ω/sq after laser process optimization. These findings establish PBAT composites as promising candidates for sustainable transient electronics. Full article

Different types of polymeric materials are used as footbeds in shoes. Environmental degradation behavior of polymeric footbed materials is an important parameter for understanding materials’ environmental footprint. Most of the previous studies focus on geotextiles, polymeric insulation materials, and exposure behaviors that are not the same due to the nature of applications of geotextiles and insulations being completely different from the footbeds. There is a lack of studies to understand artificial weathering, the influence of physical–chemical factors, and the subsequent behavior of different types of footbeds. In this paper, we have selected three needle-punched nonwoven footbed materials and studied their environmental degradation behavior by subjecting them to artificial weathering using different exposure durations, viz. 120 h, 240 h, and 360 h. The physical–chemical properties of polymeric footbed materials were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and thermogravimetric analysis (TGA). The selected polymeric footbed materials were made from recycled polyester (RPET), hemp, and shoddy fibers. Furthermore, the RPET footbed was tested for biodegradation in soil and compost conditions for 120 days. The footbed materials were also tested for physical and performance (tensile and abrasion resistance) properties. Hemp footbed materials undergo abiotic degradation after 120 h, but in the case of RPET, it undergoes abiotic degradation after 360 h, resulting in a fragmentation process due to synergistic effects of chemical and hydrolytic degradations. From the DSC results, RPET undergoes a slight thermal transition under abiotic degradation after 360 h, indicating that environmental abiotic factors influence degradation behavior. The tensile and abrasion resistance properties of RPET were the highest, followed by hemp and shoddy materials. The tensile strength range of the materials was between 50.74 and 851.44 N. The weight loss range after abrasion resistance was 0.016–0.014%. From the RPET biodegradation test in soil and compost conditions, the evolved CO₂ was 20% and 59%, respectively, after 110 days. The DSC and TGA results indicate that the hemp footbed materials have a higher rate of abiotic degradation as compared to the RPET and shoddy footbed materials. From the RPET biodegradation test in soil and compost conditions, the CO₂ degradation values were 20% and 59%, respectively. The obtained degradation results indicate that the synergistic effect of abiotic and biotic conditions greatly influences footbed materials’ biodegradation under natural environmental conditions. Full article

2,5-furandicarboxylic acid (FDCA), a high-value biomass-derived monomer, serves as a crucial building block for sustainable polymers including polyesters, polyamides, and polyurethanes. This study systematically investigated the catalytic oxidation of 5-hydroxymethylfurfural (HMF) to FDCA over Pt/Al₂O₃ and Pt–Bi/Al₂O₃ catalysts. The 5Pt/Al₂O₃ catalyst yielded 60.6% FDCA after 12 h under optimized conditions (80 °C, 0.1 MPa O₂, 1 equiv. Na₂CO₃). Remarkably, Bi-modified 5Pt–1Bi/Al₂O₃ catalyst dramatically enhanced catalytic performance, achieving 94.1% FDCA yield within 6 h under optimized conditions (80 °C, 1.5 MPa O₂, 2 equiv. Na₂CO₃). Comprehensive characterization revealed that the exceptional activity originates from Bi–O–Pt interactions that modulate the electronic structure and oxidation state of Pt active sites, which facilitates the oxidation of intermediate 5-formyl-2-furancarboxylic acid (FFCA) to FDCA, the rate-limiting step of HMF oxidation. This work demonstrates an efficient Bi-promoted Pt catalytic system for FDCA production with significant potential for industrial application. Full article

Clear aligners have gained popularity in orthodontics due to their aesthetics, comfort, and removability; however, their prolonged intraoral wear and frequent removal–reinsertion cycles create favorable conditions for microbial colonization. This in vitro study evaluated the efficacy of seven commercially available mouthwash formulations in inhibiting biofilms of Streptococcus mutans, Streptococcus oralis, and Candida albicans formed on four different clear aligner materials. Standardized aligner fragments were incubated for 24 h with microbial suspensions to allow biofilm formation, treated for 1 min with one of the mouthwashes, and then assessed for residual viability through spectrophotometric optical density measurements after a further 24 h incubation. Biofilm inhibition varied according to both mouthwash composition and aligner material. The chlorhexidine-based rinse (MW-D) consistently showed the highest inhibition across microorganisms, while the fluoride–cetylpyridinium chloride rinse (MW-B) performed strongly for S. oralis and C. albicans. An essential oil-based formulation with xylitol (MW-G) showed notable antifungal activity against C. albicans. Monolayer polyurethane aligners generally achieved higher inhibition rates than multilayer or copolyester-based materials. These findings indicate that antimicrobial efficacy on aligners depends on both mouthwash type and material, supporting a tailored approach to biofilm management in clear aligner therapy to reduce the risk of caries, periodontal disease, and candidiasis. Full article

This study evaluated the impact of cotton (CO) and polyester (PES) fabric support modules on the filtering efficiency of chitosan/silver nanoparticles/graphene oxide (CS/AgNP/GO). The experimental results showed that both CO and PES fabrics may serve as excellent support modules for CS/AgNP/GO composite membranes, enhancing water permeability and greatly improving the filtration process. The effectiveness of the membrane separation process depends on how the molecules in the composite structure interact with the supporting components. Both fabric-supported modules improved the wettability of the membrane; however, the CO is more hydrophilic than the PES of roughly the same thickness. This was attributed to improved wettability and capillary pore diameters inside the molecular structure of the CO-supported membrane, in contrast to the PES-supported modified CS composite within the same timeframe, confirming a higher adhesive force resulting from heightened hydrophilicity. The improved chemical bonding between the CS composite and the support materials resulted in an increase in mechanical properties. The maximum tensile strength of 48.46 MPa was attained by the CO-supported composite, followed by the PES-supported modified CS filtration membrane (43.73 MPa), while the non-fabric-supported membrane exhibited the lowest tensile strength of 37.23 MPa with the highest elongation at break (64.2%). Full article

This work presents the design, fabrication and characterisation of an improved textile energy storage device implemented in a single layer of polyester cotton and silk fabric. To achieve this, the energy storage device has evolved from an electrical double-layer (EDL) supercapacitor to a zinc-ion supercapacitor (ZHSC) with an optimised co-polymer membrane containing a polyethene oxide (PEO) additive and a polyvinylidene (PVDF)-based organic electrolyte. The flexible textile ZHSC achieved an areal capacitance of 159.5 mF cm⁻² and an energy density of 52.3 µWh cm⁻² (increasing by a factor of 4 and 1.8, respectively, on the previous work) with a power density of 0.27 mW cm⁻² and good bending stability. Full article

Phoenix Dancong tea essential oil possesses unique aroma characteristics and bioactivities, offering broad application potential in the food, pharmaceutical, and daily chemical fields. To achieve efficient extraction and expand its use in functional textiles, supercritical CO₂ (SC-CO₂) extraction was employed to optimize the extraction process of Phoenix Dancong tea essential oil. Based on single-factor experiments, the optimal extraction conditions were determined as follows: pressure of 25 MPa, temperature of 50 °C, CO₂ flow rate of 8 L/h, and extraction time of 3 h, resulting in an essential oil yield of 1.12%. Response surface methodology (RSM) revealed that the experimental data fit the regression model well (R² = 95.49%, R²Adj = 89.69%). Furthermore, the extracted essential oil was blade-coating to cotton, nylon, polyester, and wool fabrics to evaluate its aroma retention performance. Results indicated that cotton fibers exhibited the best absorption and sustained fragrance retention, maintaining a high odor grade even after 8 weeks. This study provides a theoretical basis and practical reference for the green extraction of Phoenix Dancong tea essential oil and its application in smart aromatic textiles. Full article

Triaxial electrospinning was used to fabricate fiber membranes composed of polycaprolactone (PCL), poly(lactic-co-glycolide) (PLGA), and gelatin (GT), designed as carriers for curcumin (Cur) delivery. Here, synthetic polyesters acted as core and shell layers, while GT formed the middle layer containing Cur at varying concentrations. This paper aimed to demonstrate the effect of a shell layer by rearranging the core and shell layers on the kinetics of model drug delivery. In vitro release results indicated the shell layer considerably affected the release behavior, reducing the initial burst release by up to 28% in triaxial fibers compared to coaxial fibers in PLGA-shell forms. The release kinetics were interpreted using the Gallagher–Corrigan model. The membranes were also evaluated for their morphological properties. PLGA-shell-layered triaxial fibers exhibited pore sizes up to approximately 11 µm, small enough to prevent cell migration, while providing higher permeability. The surface wettability analysis of the developed fibers showed that all forms exhibited hydrophilic properties. Furthermore, the cytocompatibility of the fiber membranes was confirmed with the relative cell viability of over 80%. Triaxial fibers with different shell layers displayed similar release trends, yet fibers with the PLGA shell layer demonstrated more favorable performance, attributed to its layer configuration. These findings suggest that the strategic positioning of polymers in triaxial electrospun membranes could be pivotal in optimizing drug delivery systems. Full article

Developing sustainable textile finishes that enhance moisture management and breathability remains a significant challenge in designing high-performance apparel. In this study, we propose an eco-friendly coating strategy utilizing an aqueous dispersion of poly(3-hydroxybutyrate)-diol (PHB.E.0), a member of the polyhydroxyalkanoate (PHA) family. This coating was applied to woven polyester (PES) and cotton (CO) fabrics using a low-impact spray-coating technique, aiming to improve functional properties while maintaining environmental sustainability. This solvent-free process significantly reduces chemical usage and energy demand, aligning with sustainable manufacturing goals. Successful deposition of the coating was confirmed by scanning electron microscopy (SEM), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), elemental (C/O) analysis, and thermogravimetric analysis (TGA), which also revealed substrate-dependent thermal behaviour. Wettability, water absorption, and permeability tests showed that the coated fabrics retained their hydrophilic character. PHB.E.0 coatings led to a significant reduction in air permeability, particularly after hot pressing at 180 °C, from ≈670 to ≈171 L·m⁻² s⁻¹ for PES and from ≈50 to ≈30 L·m⁻²·s⁻¹ for CO, without compromising water vapor permeability. All coated samples maintained high breathability, essential for wearer comfort. These results demonstrate that PHB.E.0 coatings enhance wind resistance while preserving moisture vapor transport, offering a sustainable and effective solution for functional sportswear. Full article

A versatile, sustainable feedstock pathway to bio-based polymeric materials was developed utilizing lignin biomass and the ring-opening copolymerization (ROCOP) of cyclic anhydrides and epoxides to synthesize functional, lignin-derived, fully bio-based polyester polyols. The initial goal was to make the ROCOP reaction more applicable to bio-derived starting materials and more attractive to commercialization by conducting the polymerization under less constrained and industrially relevant conditions in air and without the extensive purification of reagents, catalysts, or solvents, typically used in the literature. A refined ROCOP system was applied as a powerful tool in lignin valorization by successfully synthesizing the lignin-derived copolyester prepolymers from lignin models and depolymerized native lignin sourced from the reductive catalytic fractionation of Pinus radiata wood biomass. After mechanistic studies based on NMR characterization, an alternative ROCOP-style mechanism was proposed. This was found to be (1) contributing to the acceleration of the observed reaction rates with added [PPNCl] organo-catalyst and (2) ‘self-initiation/self-promoted’ ROCOP without any added external [PPNCl] catalyst, likely due to the presence of inherent [OH] groups/ species in the lignin-derived glycidyl ether monomer promoting reactivity. As a final goal, the potential of these lignin-derived polyesters as intermediate polyols was demonstrated by applying them in the synthesis of polyurethane (PU) film materials with a high biomass content of 75–79%. A dramatic range of thermomechanical properties was observed for the resulting materials, demonstrating how the ROCOP reaction can be used to tailor the properties of the functional polyester and PU material based on the nature of the epoxide and anhydride substrates used. These findings help endeavors towards predicting the relationship between chemical structure and material thermomechanical properties and performance, relevant for industrial applications. Overall, this study demonstrated the proof of concept that PU materials can be prepared from lignocellulosic biomass utilizing industrially feasible ROCOP of bio-derived cyclic anhydrides and epoxides. Full article

A series of PTT-b-PTMG copolyesters was synthesized via direct esterification followed by melt polycondensation using purified terephthalic acid (PTA), bio-based 1,3-propanediol (PDO), and poly(tetramethylene glycol) (PTMG) of varying molecular weights (650–3000 g/mol). The resulting materials were comprehensively characterized in terms of chemical structure, molecular weight, thermal behavior, phase morphology, crystalline architecture, and mechanical performance using a range of analytical techniques: Fourier-transform infrared spectroscopy (FTIR), ¹H-NMR, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), dynamic mechanical thermal analysis (DMA), tensile testing, and other standard physical methods. FTIR, ¹H-NMR, and GPC data confirmed the successful incorporation of both PTT-hard and PTMG-soft segments into the copolymer backbone. As the PTMG molecular weight increased, the average sequence length of the PTT-hard segments (L_n,T) also increased, leading to higher melting (T_m) and crystallization (T_c) temperatures, albeit with a slight reduction in overall crystallinity. DMA results indicated enhanced microphase separation between hard and soft domains with increasing PTMG molecular weight. WAXS and SAXS analyses further revealed that the crystalline structure and long-range ordering were strongly dependent on the copolymer composition and block architecture. Mechanical testing showed that tensile strength at break remained relatively constant across the series, while Young’s modulus increased significantly with higher PTMG molecular weight—concurrently accompanied by a decrease in elongation at break. Furthermore, the elastic deformability and recovery behavior of PTT-b-PTMG block copolymers were evaluated through cyclic tensile testing. TGA confirmed that all copolyesters exhibited excellent thermal stability. This study demonstrates that the physical and mechanical properties of bio-based PTT-b-PTMG elastomers can be effectively tailored by adjusting the molecular weight of the PTMG-soft segment, offering valuable insights for the rational design of sustainable thermoplastic elastomers with tunable performance. Full article