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Search Results (2,063)

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Keywords = crystalline polymer

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16 pages, 1192 KiB  
Review
The Use of Non-Degradable Polymer (Polyetheretherketone) in Personalized Orthopedics—Review Article
by Gabriela Wielgus, Wojciech Kajzer and Anita Kajzer
Polymers 2025, 17(15), 2158; https://doi.org/10.3390/polym17152158 (registering DOI) - 7 Aug 2025
Abstract
Polyetheretherketone (PEEK) is a semi-crystalline thermoplastic polymer which, due to its very high mechanical properties and high chemical resistance, has found application in the automotive, aerospace, chemical, food and medical (biomedical engineering) industries. Owing to the use of additive technologies, particularly the Fused [...] Read more.
Polyetheretherketone (PEEK) is a semi-crystalline thermoplastic polymer which, due to its very high mechanical properties and high chemical resistance, has found application in the automotive, aerospace, chemical, food and medical (biomedical engineering) industries. Owing to the use of additive technologies, particularly the Fused Filament Fabrication (FFF) method, this material is the most widely used plastic to produce skull reconstruction implants, parts of dental implants and orthopedic implants, including spinal, knee and hip implants. PEEK enables the creation of personalized implants, which not only have greater elasticity compared to implants made of metal alloys but also resemble the physical properties of the cortical layer of human bone in terms of their mechanical properties. Therefore, the aim of this article is to characterize polyether ether ketone as an alternative material used in the manufacturing of implants in orthopedics and dentistry. Full article
(This article belongs to the Section Polymer Applications)
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15 pages, 2161 KiB  
Article
Preparation of PLLA and PLGA Copolymers with Poly(ethylene adipate) Through Reactive Melt Mixing: Structural Characterization, Thermal Properties, and Molecular Mobility Insights
by Evi Christodoulou, Christina Samiotaki, Alexandra Zamboulis, Rizos Evangelos Bikiaris, Panagiotis A. Klonos, Apostolos Kyritsis and Dimitrios N. Bikiaris
Macromol 2025, 5(3), 35; https://doi.org/10.3390/macromol5030035 - 7 Aug 2025
Abstract
In this study, a series of copolymers was synthesized using the promising biodegradable polymers Poly(L-lactic acid) (PLLA), Poly(lactic-co-glycolic acid) (PLGA), and Poly(ethylene adipate) (PEAd), known for their high potential. PEAd was synthesized through a two-step melt polycondensation process and then used to prepare [...] Read more.
In this study, a series of copolymers was synthesized using the promising biodegradable polymers Poly(L-lactic acid) (PLLA), Poly(lactic-co-glycolic acid) (PLGA), and Poly(ethylene adipate) (PEAd), known for their high potential. PEAd was synthesized through a two-step melt polycondensation process and then used to prepare copolymers with PLLA (PLLA-co-PEAd) and PLGA (PLGA-co-PEAd) at weight ratios of 90/10 and 75/25, respectively. The synthesized materials, along with the starting polymers, were extensively characterized for their structure, molecular weight, crystallinity, and thermal behavior. These novel systems exhibit single thermal transitions, e.g., glass transition. The incorporation of PEAd into the copolymers induced a plasticizing effect, evidenced by a consistent decrease in the glass transition temperature. Due to the latter effect in combination with the Mw drop, the facilitation of crystal nucleation was observed. Finally, the results by dielectric spectroscopy on the local and segmental molecular mobility provided additional proof for the homogeneity of the systems, as manifested, e.g., by the recording of single segmental relaxation processes. Overall, the findings indicate that the PLLA-co-PEAd and PLGA-co-PEAd copolymers hold significant potential, and the use of complementary experimental techniques offers valuable insights and indirect indications of their properties. Full article
(This article belongs to the Collection Advances in Biodegradable Polymers)
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20 pages, 3077 KiB  
Article
Influence of Carboxylic Acids (CAs) on the Structure–Properties Relationship in PLA/Pecan Nutshell (PN) Composites
by Giordano Pierozan Bernardes, Matheus de Prá Andrade and Matheus Poletto
J. Compos. Sci. 2025, 9(8), 422; https://doi.org/10.3390/jcs9080422 - 6 Aug 2025
Abstract
Reinforcing PLA composites with natural fibres is a prominent strategy for improving PLA’s properties while benefiting from its intrinsic biodegradation. However, these composites may be susceptible to an inefficient stress-transferring process due to the weak intermolecular interactions between PLA and natural fibres. A [...] Read more.
Reinforcing PLA composites with natural fibres is a prominent strategy for improving PLA’s properties while benefiting from its intrinsic biodegradation. However, these composites may be susceptible to an inefficient stress-transferring process due to the weak intermolecular interactions between PLA and natural fibres. A well-known practice is to incorporate coupling agents to improve polymer–fibre adhesion, such as carboxylic acids (CAs) and grafted copolymers. CAs are a more affordable and biodegradable option for improving PLA/natural fibre interface strength, resulting in a material with superior mechanical and thermal properties. In this context, this research discusses the potential use of mono (C6 and C8) and di (CC6 and CC8) carboxylic acids as coupling agents in PLA/pecan nutshells (PN) composites. PLA/PN composites with four different CAs were processed in a twin-screw extruder and subsequently injection moulded. The results indicated an increase in the flexural strength of the PLA due to the presence of PN in the neat composite. The use of CAs increased the storage modulus of PLA/PN composites, while C6 and CC8 reduced the PLA composite tan δ peak height. The PLA’s Tg in PLA/PN composite shifted to lower temperatures after the incorporation of CAs while increasing the PLA crystallinity degree. These results strongly suggested that besides acting as efficient coupling agents, these acids also exerted roles as nucleating agents and plasticisers. Full article
(This article belongs to the Section Polymer Composites)
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26 pages, 5455 KiB  
Article
Features of Thermal Stabilization of PVC Modified with Microstructured Titanium Phosphate
by Irina N. Vikhareva, Anton Abramian, Dragan Manojlović and Oleg Bol’shakov
Polymers 2025, 17(15), 2140; https://doi.org/10.3390/polym17152140 - 5 Aug 2025
Viewed by 46
Abstract
Poly(vinyl chloride) (PVC) undergoes thermal degradation during processing and operation, which necessitates the use of effective thermal stabilizers. The purpose of this work is to comprehensively evaluate the potential of new hierarchically structured titanium phosphates (TiP) with controlled morphology as thermal stabilizers of [...] Read more.
Poly(vinyl chloride) (PVC) undergoes thermal degradation during processing and operation, which necessitates the use of effective thermal stabilizers. The purpose of this work is to comprehensively evaluate the potential of new hierarchically structured titanium phosphates (TiP) with controlled morphology as thermal stabilizers of plasticized PVC, focusing on the effect of morphology and Ti/P ratio on their stabilizing efficiency. The thermal stability of the compositions was studied by thermogravimetric analysis (TGA) in both inert (Ar) and oxidizing (air) atmospheres. The effect of TiP concentration and its synergy with industrial stabilizers was analyzed. An assessment of the key degradation parameters is given: the temperature of degradation onset, the rate of decomposition, exothermic effects, and the carbon residue yield. In an inert environment, TiPMSI/TiPMSII microspheres demonstrated an optimal balance by increasing the temperature of degradation onset and the residual yield while suppressing the rate of decomposition. In an oxidizing environment, TiPR rods and TiPMSII microspheres provided maximum stability, enhancing resistance to degradation onset and reducing the degradation rate by 10–15%. Key factors of effectiveness include ordered morphology (spheres, rods); the Ti-deficient Ti/P ratio (~0.86), which enhances HCl binding; and crystallinity. The stabilization mechanism of titanium phosphates is attributed to their high affinity for hydrogen chloride (HCl), which catalyzes PVC chain scission, a catalyst for the destruction of the PVC chain. The unique microstructure of titanium phosphate provides a high specific surface area and, as a result, greater activity in the HCl neutralization reaction. The formation of a sol–phosphate framework creates a barrier to heat and oxygen. An additional contribution comes from the inhibition of oxidative processes and the possible interaction with unstable chlorallyl groups in PVC macromolecules. Thus, hierarchically structured titanium phosphates have shown high potential as multifunctional PVC thermostabilizers for modern polymer materials. Potential applications include the development of environmentally friendly PVC formulations with partial or complete replacement of toxic stabilizers, the optimization of thermal stabilization for products used in aggressive environments, and the use of hierarchical TiP structures in flame-resistant and halogen-free PVC-based compositions. Full article
(This article belongs to the Section Polymer Processing and Engineering)
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15 pages, 3303 KiB  
Article
Effect of Ozone on Nonwoven Polylactide/Natural Rubber Fibers
by Yulia V. Tertyshnaya, Svetlana G. Karpova and Maria V. Podzorova
Polymers 2025, 17(15), 2102; https://doi.org/10.3390/polym17152102 - 31 Jul 2025
Viewed by 147
Abstract
Ozone is a powerful destructive agent in the oxidative process of polymer composites. The destructive ability of ozone depends primarily on its concentration, duration of exposure, the type of polymer, and its matrix structure. In this work, nonwoven PLA/NR fibers with natural rubber [...] Read more.
Ozone is a powerful destructive agent in the oxidative process of polymer composites. The destructive ability of ozone depends primarily on its concentration, duration of exposure, the type of polymer, and its matrix structure. In this work, nonwoven PLA/NR fibers with natural rubber contents of 5, 10, and 15 wt.% were obtained, which were then subjected to ozone oxidation for 800 min. The effect of ozone treatment was estimated using various methods of physicochemical analysis. The visual effect was manifested in the form of a change in the color of PLA/NR fibers. The method of differential scanning calorimetry revealed a change in the thermophysical characteristics. The glass transition and cold crystallization temperatures of polylactide shifted toward lower temperatures, and the degree of crystallinity increased. It was found that in PLA/NR fiber samples, the degradation process predominates over the crosslinking process, as an increase in the melt flow rate by 1.5–1.6 times and a decrease in the correlation time determined by the electron paramagnetic resonance method were observed. The IR Fourier method recorded a change in the chemical structure during ozone oxidation. The intensity of the ether bond bands changed, and new bands appeared at 1640 and 1537 cm−1, which corresponded to the formation of –C=C– bonds. Full article
(This article belongs to the Special Issue Natural Degradation of Polymers)
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33 pages, 2684 KiB  
Review
Biocompatible Natural Polymer-Based Amorphous Solid Dispersion System Improving Drug Physicochemical Properties, Stability, and Efficacy
by Arif Budiman, Helen Ivana, Kelly Angeline Huang, Stella Aurelia Huang, Mazaya Salwa Nadhira, Agus Rusdin and Diah Lia Aulifa
Polymers 2025, 17(15), 2059; https://doi.org/10.3390/polym17152059 - 28 Jul 2025
Viewed by 378
Abstract
Poor aqueous solubility still disqualifies many promising drug candidates at late stages of development. Amorphous solid dispersion (ASD) technology solves this limitation by trapping the active pharmaceutical ingredient (API) in a high-energy, non-crystalline form, yet most marketed ASDs rely on synthetic carriers such [...] Read more.
Poor aqueous solubility still disqualifies many promising drug candidates at late stages of development. Amorphous solid dispersion (ASD) technology solves this limitation by trapping the active pharmaceutical ingredient (API) in a high-energy, non-crystalline form, yet most marketed ASDs rely on synthetic carriers such as polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose (HPMC), which raise concerns about long-term biocompatibility, residual solvent load, and sustainability. This study summarizes the emergence of natural polymer-based ASDs (NP-ASDs), along with the bond mechanism reactions through which these natural polymers enhance drug performance. As a result, NP-ASDs exhibit improved physical stability and significantly enhance the dissolution rate of poorly soluble drugs. The structural features of natural polymers play a critical role in stabilizing the amorphous state and modulating drug release profiles. These findings support the growing potential of NP-ASDs as sustainable and biocompatible alternatives to synthetic carriers in pharmaceutical development. Full article
(This article belongs to the Section Biobased and Biodegradable Polymers)
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17 pages, 1314 KiB  
Article
Enhancing Biodegradation of Poly(lactic acid) in Compost at Room Temperature by Compounding Jade Particles
by Lilian Lin, Matthew Joe, Quang A. Dang and Heon E. Park
Polymers 2025, 17(15), 2037; https://doi.org/10.3390/polym17152037 - 26 Jul 2025
Viewed by 423
Abstract
Although PLA is an attractive biodegradable polymer, its degradation under natural conditions is often slow. This study investigates whether incorporating pounamu (New Zealand jade) particles into PLA can enhance its biodegradation rate under composting conditions at room temperature. PLA composites containing 0 to [...] Read more.
Although PLA is an attractive biodegradable polymer, its degradation under natural conditions is often slow. This study investigates whether incorporating pounamu (New Zealand jade) particles into PLA can enhance its biodegradation rate under composting conditions at room temperature. PLA composites containing 0 to 15 wt% pounamu were fabricated using both compression molding and 3D printing. A simple, reproducible protocol based on residual mass measurement was developed to monitor the biodegradation process over a 12-month period. The results showed that increasing pounamu content consistently accelerated mass loss of the composite in the compost, indicating enhanced biodegradation. The 3D-printed samples degraded more rapidly than compression-molded ones. This was attributed to the layered structure, internal microcavities, and lower crystallinity of the 3D-printed samples, which provided greater surface area and accessibility for microbial activity. These findings highlight the dual role of pounamu as both a crystallization promoter and a facilitator of biodegradation and underscore the importance of the processing method when designing biodegradable polymer composites for real-world applications. Full article
(This article belongs to the Special Issue Advances in Polymer Composites with Upcycling Waste)
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15 pages, 2393 KiB  
Article
Determination of Time and Concentration Conditions Affecting Polylactic Acid (Pla) Production
by Jorge Braulio Amaya and Gabriela Vaca
Polymers 2025, 17(15), 2009; https://doi.org/10.3390/polym17152009 - 23 Jul 2025
Viewed by 247
Abstract
Polylactic acid (PLA) is a renewable biopolymer that has attracted considerable interest due to its ability to replace petroleum-based synthetic polymers, thereby offering a more sustainable alternative to global environmental concerns. This study focused on evaluating the effect of catalyst concentration and reaction [...] Read more.
Polylactic acid (PLA) is a renewable biopolymer that has attracted considerable interest due to its ability to replace petroleum-based synthetic polymers, thereby offering a more sustainable alternative to global environmental concerns. This study focused on evaluating the effect of catalyst concentration and reaction time on the efficiency of PLA synthesis via the Ring-Opening Polymerization (ROP) technique. The process involved a lactic acid esterification stage (using 88% lactic acid) to obtain lactide, employing 40% and 60% (v/v) sulfuric acid concentrations, followed by polymerization at various reaction times (10, 15, 20, and 30 min). Analysis of variance (ANOVA) results revealed that the 40% catalyst concentration had a statistically significant effect on polymer yield (p = 0.032), whereas reaction time showed no statistical significance (p = 0.196), although the highest yields were recorded at 10 and 15 min. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the presence of the characteristic functional groups of PLA, and Differential Scanning Calorimetry (DSC) revealed a semi-crystalline structure with a high melting temperature, indicating good thermal stability. These results validate the viability of PLA as a functional and sustainable biopolymer. Full article
(This article belongs to the Special Issue Advanced Polymer Materials: Synthesis, Structure, and Properties)
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14 pages, 2090 KiB  
Article
Strong Nucleating Effect of Si-Containing Tri-Block Oligomers on Poly(Ethylene Terephthalate)
by Quankai Sun, Yao Wang, Miaorong Zhang, Linjun Huang, Pengwei Zhang, Kang Li, Wei Wang and Jianguo Tang
Molecules 2025, 30(15), 3077; https://doi.org/10.3390/molecules30153077 - 23 Jul 2025
Viewed by 180
Abstract
The development of a silane coupling agent with an aminopropyl structure as a nucleating agent for poly(ethylene terephthalate) (PET) is reported in this study. The tri–block oligomers nucleating agent was formed by 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane/oxalic acid/low molecular weight PET (LPOBD). It was subsequently cross-linked with [...] Read more.
The development of a silane coupling agent with an aminopropyl structure as a nucleating agent for poly(ethylene terephthalate) (PET) is reported in this study. The tri–block oligomers nucleating agent was formed by 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane/oxalic acid/low molecular weight PET (LPOBD). It was subsequently cross-linked with tetraethyl orthosilicate to form LPOBD-T. Composites of LPOBD/PET and LPOBD-T/PET were prepared by melt blending, and their thermal and crystallization behaviors were analyzed using XRD, DSC, TG, and POM. The results indicated that not only did the triblock polymer nucleating agent LPOBD exhibit a strong nucleation effect, but the crosslinked LPOBD-T also demonstrated superior crystallization performance. Specifically, the crystallinity of the 1 wt% LPOBD-T/PET composite increased by 3.3%, the crystallization temperature rose by 21.1 °C, and the t1/2 was reduced by 53 s. Moreover, the crystalline morphology was more uniform. These findings indicate that the tri-block oligomers synthesized from a silane coupling agent serve as effective nucleating agents for PET. Full article
(This article belongs to the Special Issue Recent Advances in Functional Composite Materials)
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30 pages, 2013 KiB  
Review
Biopolymers in Biotechnology and Tissue Engineering: A Comprehensive Review
by Maciej Grabowski, Dominika Gmyrek, Maria Żurawska and Anna Trusek
Macromol 2025, 5(3), 34; https://doi.org/10.3390/macromol5030034 - 21 Jul 2025
Viewed by 809
Abstract
Since the mid-19th century, researchers have explored the potential of bio-based polymeric materials for diverse applications, with particular promise in medicine. This review provides a focused and detailed examination of natural and synthetic biopolymers relevant to tissue engineering and biomedical applications. It emphasizes [...] Read more.
Since the mid-19th century, researchers have explored the potential of bio-based polymeric materials for diverse applications, with particular promise in medicine. This review provides a focused and detailed examination of natural and synthetic biopolymers relevant to tissue engineering and biomedical applications. It emphasizes the structural diversity, functional characteristics, and processing strategies of major classes of biopolymers, including polysaccharides (e.g., hyaluronic acid, alginate, chitosan, bacterial cellulose) and proteins (e.g., collagen, silk fibroin, albumin), as well as synthetic biodegradable polymers such as polycaprolactone, polylactic acid, and polyhydroxybutyrate. The central aim of this manuscript is to elucidate how intrinsic properties—such as molecular weight, crystallinity, water retention, and bioactivity—affect the performance of biopolymers in biomedical contexts, particularly in drug delivery, wound healing, and scaffold-based tissue regeneration. This review also highlights recent advancements in polymer functionalization, composite formation, and fabrication techniques (e.g., electrospinning, bioprinting), which have expanded the application potential of these materials. By offering a comparative analysis of structure–property–function relationships across a diverse range of biopolymers, this review provides a comprehensive reference for selecting and engineering materials tailored to specific biomedical challenges. It also identifies key limitations, such as production scalability and mechanical performance, and suggests future directions for developing clinically viable and environmentally sustainable biomaterial platforms. Full article
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10 pages, 2328 KiB  
Article
Vertical Hot-Melt Extrusion: The Next Challenge in Innovation
by Maël Gallas, Ghouti Medjahdi, Pascal Boulet and Victoire de Margerie
Pharmaceutics 2025, 17(7), 939; https://doi.org/10.3390/pharmaceutics17070939 - 21 Jul 2025
Viewed by 396
Abstract
Background/Objectives: Hot-melt extrusion (HME) has become a key technology in pharmaceutical formulation, particularly for enhancing the solubility of poorly soluble Active Pharmaceutical Ingredients (APIs). While horizontal HME is widely adopted, vertical HME remains underexplored despite its potential benefits in footprint reduction, feeding efficiency, [...] Read more.
Background/Objectives: Hot-melt extrusion (HME) has become a key technology in pharmaceutical formulation, particularly for enhancing the solubility of poorly soluble Active Pharmaceutical Ingredients (APIs). While horizontal HME is widely adopted, vertical HME remains underexplored despite its potential benefits in footprint reduction, feeding efficiency, temperature control, and integration into continuous manufacturing. This study investigates vertical HME as an innovative approach in order to optimize drug polymer interactions and generate stable amorphous dispersions with controlled release behavior. Methods: Extrusion trials were conducted using a vertical hot-melt extruder developed by Rondol Industrie (Nancy, France). Acetylsalicylic acid (ASA) supplied by Seqens (Écully, France) was used as a model API and processed with Soluplus® and Kollidon® 12 PF (BASF, Ludwigshafen, Germany). Various process parameters (temperature, screw speed, screw profile) were explored. The extrudates were characterized by powder X-ray diffraction (PXRD) and small-angle X-ray scattering (SAXS) to evaluate crystallinity and microstructure. In vitro dissolution tests were performed under sink conditions using USP Apparatus II to assess drug release profiles. Results: Vertical HME enabled the formation of homogeneous amorphous solid dispersions. PXRD confirmed the absence of residual crystallinity, and SAXS revealed nanostructural changes in the polymer matrix influenced by drug loading and thermal input. In vitro dissolution demonstrated enhanced drug release rates compared to crystalline ASA, with good reproducibility. Conclusions: Vertical HME provides a compact, cleanable, and modular platform that supports the development of stable amorphous dispersions with controlled release. It represents a robust and versatile solution for pharmaceutical innovation, with strong potential for cost-efficient continuous manufacturing and industrial-scale adoption. Full article
(This article belongs to the Special Issue Advances in Hot Melt Extrusion Technology)
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13 pages, 3594 KiB  
Article
The Synthesis of New Chalcogenides from the System GeTe6-Cu and a Layered Structure Based on Them and an Azo Polymer for Application in Optoelectronics
by Yordanka Trifonova, Ani Stoilova, Deyan Dimov, Georgi Mateev, Dimana Nazarova, Lian Nedelchev, Vladislava Ivanova and Vanya Lilova
Materials 2025, 18(14), 3387; https://doi.org/10.3390/ma18143387 - 18 Jul 2025
Viewed by 299
Abstract
New bulk chalcogenides from the system (GeTe6)1−xCux, where x = 5, 10, 15 and 20 mol%, have been synthesized. The structure and composition of the materials were studied using X-ray powder diffraction (XRD) and energy-dispersive spectroscopy (EDS). [...] Read more.
New bulk chalcogenides from the system (GeTe6)1−xCux, where x = 5, 10, 15 and 20 mol%, have been synthesized. The structure and composition of the materials were studied using X-ray powder diffraction (XRD) and energy-dispersive spectroscopy (EDS). Scanning electron microscopy (SEM) was applied to analyze the surface morphology of the samples. Some thermal characteristics such as the glass transition, crystallization and melting temperature and some physico-chemical properties such as the density, compactness and molar and free volumes were also determined. The XRD patterns show sharp diffraction peaks, indicating that the synthesized new bulk materials are crystalline. The following four crystal phases were determined: Te, Cu, CuTe and Cu2GeTe3. The results from the EDS confirmed the presence of Ge, Te and Cu in the bulk samples in concentrations in good correspondence with those theoretically determined. A layered thin-film material based on Ge14Te81Cu5, which exhibits lower network compactness compared to the other synthesized new chalcogenides, and the azo polymer PAZO was fabricated, and the kinetics of the photoinduced birefringence at 444 nm was measured. The results indicated an increase in the maximal induced birefringence for the layered structure in comparison to the non-doped azo polymer film. Full article
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15 pages, 7412 KiB  
Article
Effect of Sequence-Based Incorporation of Fillers, Kenaf Fiber and Graphene Nanoplate, on Polypropylene Composites via a Physicochemical Compounding Method
by Soohyung Lee, Kihyeon Ahn, Su Jung Hong and Young-Teck Kim
Polymers 2025, 17(14), 1955; https://doi.org/10.3390/polym17141955 - 17 Jul 2025
Viewed by 327
Abstract
Natural-fiber-reinforced polypropylene (PP) composites are gaining increasing interest as lightweight, sustainable alternatives for various packaging and applications. This study investigates the effect of filler addition sequence on the mechanical, morphological, thermal, and dynamic mechanical properties of PP-based composites reinforced with graphite nanoplatelets (GnP) [...] Read more.
Natural-fiber-reinforced polypropylene (PP) composites are gaining increasing interest as lightweight, sustainable alternatives for various packaging and applications. This study investigates the effect of filler addition sequence on the mechanical, morphological, thermal, and dynamic mechanical properties of PP-based composites reinforced with graphite nanoplatelets (GnP) and kenaf fiber (KF). Two filler incorporation sequences were evaluated: GnP/KF/PP (GnP initially mixed with KF before PP addition) and GnP/PP/KF (KF added after mixing GnP with PP). The GnP/KF/PP composite exhibited superior mechanical properties, with tensile strength and flexural strength increasing by up to 25% compared to the control, while GnP/PP/KF showed a 13% improvement. SEM analyses revealed that initial mixing of GnP with KF significantly improved filler dispersion and interfacial bonding, enhancing stress transfer within the composite. XRD and DSC analyses showed reduced crystallinity and lower crystallization temperatures in the addition of KF due to restricted polymer chain mobility. Thermal stability assessed by TGA indicated minimal differences between the composites regardless of filler sequence. DMA results demonstrated a significantly higher storage modulus and enhanced elastic response in the addition of KF, alongside a slight decrease in glass transition temperature (Tg). The results emphasize the importance of optimizing filler addition sequences to enhance mechanical performance, confirming the potential of these composites in sustainable packaging and structural automotive applications. Full article
(This article belongs to the Special Issue Natural Fiber-Based Green Materials, Second Edition)
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34 pages, 3610 KiB  
Review
Metal–Organic Frameworks as Fillers in Porous Organic Polymer-Based Hybrid Materials: Innovations in Composition, Processing, and Applications
by Victor Durán-Egido, Daniel García-Giménez, Juan Carlos Martínez-López, Laura Pérez-Vidal and Javier Carretero-González
Polymers 2025, 17(14), 1941; https://doi.org/10.3390/polym17141941 - 15 Jul 2025
Viewed by 739
Abstract
Hybrid materials based on porous organic polymers (POPs) and metal–organic frameworks (MOFs) are increasing attention for advanced separation processes due to the possibility to combine their properties. POPs provide high surface areas, chemical stability, and tunable porosity, while MOFs contribute a high variety [...] Read more.
Hybrid materials based on porous organic polymers (POPs) and metal–organic frameworks (MOFs) are increasing attention for advanced separation processes due to the possibility to combine their properties. POPs provide high surface areas, chemical stability, and tunable porosity, while MOFs contribute a high variety of defined crystalline structures and enhanced separation characteristics. The combination (or hybridization) with PIMs gives rise to mixed-matrix membranes (MMMs) with improved permeability, selectivity, and long-term stability. However, interfacial compatibility remains a key limitation, often addressed through polymer functionalization or controlled dispersion of the MOF phase. MOF/COF hybrids are more used as biochemical sensors with elevated sensitivity, catalytic applications, and wastewater remediation. They are also very well known in the gas sorption and separation field, due to their tunable porosity and high electrical conductivity, which also makes them feasible for energy storage applications. Last but not less important, hybrids with other POPs, such as hyper-crosslinked polymers (HCPs), covalent triazine frameworks (CTFs), or conjugated microporous polymers (CMPs), offer enhanced functionality. MOF/HCP hybrids combine ease of synthesis and chemical robustness with tunable porosity. MOF/CTF hybrids provide superior thermal and chemical stability under harsh conditions, while MOF/CMP hybrids introduce π-conjugation for enhanced conductivity and photocatalytic activity. These and other findings confirm the potential of MOF-POP hybrids as next-generation materials for gas separation and carbon capture applications. Full article
(This article belongs to the Special Issue Organic-Inorganic Hybrid Materials, 4th Edition)
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15 pages, 3660 KiB  
Article
Microencapsulation of Analgesics as an Analog Form of Medicine
by Aidana Nakipekova, Bates Kudaibergenova, Arkady S. Abdurashitov and Gleb B. Sukhorukov
Pharmaceutics 2025, 17(7), 916; https://doi.org/10.3390/pharmaceutics17070916 - 15 Jul 2025
Viewed by 497
Abstract
Objectives: This research focuses on the development of fabrication approaches for microparticles intended for controlled drug delivery. The primary objective is to identify the most suitable polymer type, particle size, and morphology for encapsulating a water-soluble crystalline drug. Optimizing these parameters may enhance [...] Read more.
Objectives: This research focuses on the development of fabrication approaches for microparticles intended for controlled drug delivery. The primary objective is to identify the most suitable polymer type, particle size, and morphology for encapsulating a water-soluble crystalline drug. Optimizing these parameters may enhance structural stability and prolong the release of this active substance. Methods: The microparticles were fabricated through the encapsulation of a drug substance within a polymer carrier and employing polymer casting on prepatterned surfaces, followed by the loading of drug precipitates and the application of a sealing layer. The crystalline powder 1-allyl-2,5-dimethylpiperidol-4 hydrochloride served as the core cargo material, while the walls of these particles were composed of polylactic acid (PLA) and a poly (α-caprolactone) (PCL) in a 70:30 composition ratio. Results: The size and volume of the microparticles were found to be dependent on the geometric parameters of the template and the concentration of the polymer solutions. The study demonstrates the formation, physical dimensions, and particle count at varied polymer compositions and concentrations. The formation of the PLA and PCL mixture occurred solely through physical interactions. Scanning electron microscopy (SEM) and optical microscopy were employed to observe the appearance and physical dimensions of the microparticles. The obtained data confirm that tailored polymer compositions can yield consistent particle morphology and a suitable drug elution rate. Conclusions: The results indicate that microparticles sealed with an optimal polymer composition exhibit enhanced release properties. This finding highlights the feasibility of microencapsulation at precise ratios and concentrations of polymers to achieve the long-lasting effects of water-soluble drugs. Full article
(This article belongs to the Special Issue Multifunctional Nanomaterials in Drug Delivery)
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