Polymer International最新文献

Silver-containing composites formed by sputtering deposition on the surface of polylactide (PLA) films have been developed; they contain a layer of silver nanoparticles of different thicknesses depending on the deposition time, namely 1, 3 and 5 min. It was found that with a deposition time of 5 min a layer with a thickness of ca 100 nm is formed. The average size of the Ag nanoparticles is 5.9 nm, and the average specific surface area S_sp is 97 m² g⁻¹. The samples obtained were characterized by wide-angle X-ray scattering, TEM, TGA and DSC and their antimicrobial, antiviral and cytotoxic properties were studied as well. It was found that the thinnest layer of silver (deposited for 1 min) has the greatest effect on the PLA's heat resistance and glass transition temperature. PLA-Ag composites formed by silver sputtering deposition show antimicrobial activity against the studied test cultures of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, and the activity of the samples increases with increasing duration of silver deposition. PLA-Ag composites formed by silver deposition for 5 min had a weak virucidal effect against herpes simplex virus type 1 and influenza virus type A. Irrespective of the sputtering time of silver the composites obtained were not cytotoxic; at a dilution of 1:10 and more they did not significantly inhibit the viability of MDCK, BHK and Hep-2 cells. © 2025 Society of Chemical Industry.

This study focuses on the synthesis of fluorohydroxyapatite (FHA), and the realization of scaffolds by 3D printing using polylactic acid (PLA) as polymer and graphene oxide (GO). The synthesis of FHA was carried out by the usual sol–gel method. The realization of the 3D scaffold was achieved with the 3D printing method. Four scaffolds were printed with PLA: the first was made with FHA and PLA (FHA/PLA), the second was made with GO in addition to FHA and PLA (FHA/PLA/GO), and the third and fourth ones were the FHA/PLA and FHA/PLA/GO scaffolds coated with electrosprayed hydrogel solution of doxorubicin (DOX) and polyvinyl alcohol (PVA): FHA/PLA/DOX/PVA and FHA/PLA/GO/DOX/PVA. The FHA and GO powders were characterized using Fourier transform infrared analysis and X-ray diffraction analysis. A dissolution study was carried out with different contents of PVA (2.5%, 3% and 4%) to identify the scaffold with the best drug release profile. The 3% w/w PVA hydrogel solution was the best, so the drug release kinetics and drug release mechanism were studied using the most famous mathematical models: zero-order model, Higuchi's model and Korsmeyer–Peppas model (power law model). The porosity of the 3D printed scaffolds was assessed by SEM and, finally, the cellular response of each scaffold on the viability of CDD human fibroblast cells was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The sol–gel synthesis produces FHA, used in the realization of the scaffolds. The scaffolds have mixed porosity (macropores and micropores) promoting cell adhesion and proliferation, as shown by the results of the MTT assay. The addition of GO decreases the cell viability but keeps the scaffolds still biocompatible, and adding both DOX and GO to the FHA/PLA scaffolds has a negative impact on cell viability because DOX and GO remain toxic at the given percentages. © 2025 Society of Chemical Industry.

Transport phenomena of chemical species in polymers underpin many applications. This mini-review discusses several key transport scenarios in polymer gels, melts and crosslinked polymer networks. Transport mechanisms of a wide variety of penetrant and polymer chemistries are discussed via activated hopping theory and cover across the rubbery, intermediate/deeply supercooled and glassy states of polymers. Moreover, we also discuss the ionic conductivity in polymer electrolytes, emphasizing the relationship between ion diffusion and the segmental relaxation of polymers and highlighting current challenges in the community. Finally, potential research directions are suggested concerning how external fields, such as mechanical force fields, active matter and self-propelling particles, affect the particle transport in polymers. This mini-review offers a general overview of motivations for studying penetrant transports in polymers and diverse mechanisms involved. © 2024 Society of Chemical Industry.

The seawater desalination industry does not need exotic two-dimensional materials. However, it faces challenges in terms of membrane resilience to stressors such as temperature and oxidation and especially in the area of (bio)fouling. Membrane replacement is a large part of the operating expenditure of modern desalination plants and anything that increases the effective lifespan of a membrane will have economic impact. There are also emerging requirements for membrane selectivity, especially in desalination-adjacent brine-valorisation activities. These challenges provide abundant scope for the exercise of creativity by polymer scientists. © 2024 Society of Chemical Industry.

The precipitation technique was used to prepare calcium hydroxyapatite pectin (CaHAp-Pec) and calcium hydroxyapatite xanthan (CaHAp-Xan) hybrid materials. Chemical analysis, XRD, Fourier transform infrared spectroscopy, specific surface area, TGA and SEM were used to analyze the materials and the organic–inorganic interfaces. XRD and SEM investigations demonstrated that the presence of the biopolymer had an impact on both the structural and morphological properties as well as the crystallinity. The PO₄³⁻ vibration modes are visible in the IR spectra, and new vibration modes mostly associated with Xan and Pec are observed at 1594, 2878 and 3246 cm⁻¹. The specific surface area values were reduced after the chemical functionalization of CaHAp with pectin and xanthan gum. The ability of the three materials CaHAp, CaHAp-Pec and CaHAp-Xan to sorb methylene blue from aqueous solutions was assessed. The adsorption kinetics results best fitted the pseudo-second-order model. The isotherm data agreed well with the Freundlich model. The adsorption capacity values of porous composites CaHAp-Xan 5%, CaHAp-Pec 10% and CaHAp reached 277, 243 and 144 mg g⁻¹, respectively. The non-spontaneous and exothermic nature of the adsorption was demonstrated by the thermodynamic parameters (ΔG⁰, ΔH⁰ and ΔS⁰). Adsorption results confirmed that CaHAp-Xan could be used as an effective adsorbent of cationic dyes from water. © 2024 Society of Chemical Industry.

Plant oil-based acrylic monomers from hydrogenated sunflower (HFM), palm (PMM) and castor (CSM) oils were polymerized to investigate the effect of chemical composition on polymer phase transitions at temperatures relevant to physiological range. While HFM and PMM possess a highly differing content of saturated palmitic and stearic acids combined with unsaturated fatty acids, CSM contains primarily fragments based on monounsaturated ricinoleic hydroxy acid (up to 90%). Differential scanning calorimetry (DSC) measurements indicate that polymers from PMM and HFM are both semicrystalline (with T_m = −6 and −13 °C, respectively), while poly(CSM) appears to be amorphous (T_g = −49 °C). Considering the similarity in polymers' molar mass (M_n = 16 000–20 000 g mol⁻¹), the observed thermal transitions can be explained by the formation of ordered morphological domains due to the presence of saturated palmitic and stearic acid fractions in poly(PMM) and poly(HFM). For copolymers of CSM, PMM and HFM (80 wt% of monomer feed) with styrene, DSC data show two transitions corresponding to the mobility of long alkyl fatty acid side fragments and the macromolecular backbone. For copolymers of PMM and HFM, comparable values (−52.8 and −55.5 °C, respectively) were obtained, while the second transition for poly(CSM-co-styrene) appears at 35 °C. We attribute this higher value to the presence of hydroxyl groups in ricinoleic acid fragments of CSM serving as additional chain transfer sites and the formation of macromolecular fractions enriched with polystyrene fragments. We expect that the temperature transitions obtained can be relevant to the future use of these polymers for biomedical applications, including the synthesis of polymer brushes. © 2024 Society of Chemical Industry.

Thermoplastics based on polyolefins, including polypropylene, high-density polyethylene and low-density polyethylene, are extensively utilized across various packaging sectors. The selection of these materials for specific applications is influenced by multiple factors, such as the polymer's absorption characteristics and the impact on its mechanical properties when in contact with the packaged product. This study presents an experimental methodology designed to simulate the effects of absorption on the macroscopic and microscopic properties of high-density polyethylene bottles in contact with amyl acetate. Macroscopic degradation was evaluated by modeling mechanical damage using unified theory and the energy method. Analytical techniques such as gravimetric analysis, scanning electron microscopy and Fourier transform infrared spectrometry were employed. The findings of this research provide valuable insights for suppliers and industries to experimentally determine the usability and safety intervals of plastic packaging through comprehensive macroscopic and microscopic analyses within relatively short timescales. © 2024 Society of Chemical Industry.

In this study, a viable route to the development of a high-performance polyoxymethylene (POM)-based nanocomposite is proposed to overcome tribomechanical-related issues in high-precision sliding parts. Prior to melt-blending, graphene nanoplatelet (GNP) filler was processed via a series of liquid-phase exfoliation and surface modification with 3-aminopropyltriethoxysilane. Results indicate that GNP is successfully exfoliated with minimum defect ratio and improves interfacial bonding within the matrix. Uniform dispersion and stable load-transfer capability of POM/GNP with 0.5 wt% loading significantly enhanced flexural, tensile and impact strength by overall 26.4%, in contrast to unfilled POM. Dry friction tests against a steel ball also showed the lowest reduction in friction coefficient and wear rate by 22% and 40.6%, respectively, at the same amount of GNP loading due to the large specific surface coverage and lubricious transfer film chelation onto the steel counterface. Furthermore, dissipated energy accumulation by friction work was calculated in the sliding interfaces based on friction force–displacement hysteresis loop where the POM/GNP 0.5 wt% wear surface consumed ca 21.7% less energy in a dry frictional shearing process compared to neat POM. However, lack or excess loading of processed GNP exhibited insufficient or poor matrix–filler adhesion and led to deterioration of the composite properties due to particle agglomeration which can cause stress concentration and serve as a failure site. The adoption of the proposed methodology would demonstrate excellent material characteristics in thin-walled precision parts where both mechanical and tribological performances are the primary concern. © 2024 Society of Chemical Industry.