Journal of Polymer Research最新文献

Phosphorus and potassium are essential macronutrients, and potassium dihydrogen phosphate, a compound containing both, plays a vital role in plant growth and reproduction. However, its rapid leaching poses significant environmental concerns, lessening its practical utility. To overcome this issue, a biodegradable hydrogel based on amla was synthesized through graft polymerization and evaluated as a water-retaining material for agricultural applications, specifically for the controlled release of fertilizers. The synthesized hydrogel was characterized using FTIR, SEM, XRD, and TGA. Its swelling properties, water retention capacity, porosity, and density were also examined. The biodegradable nature of the synthesized hydrogel was confirmed via soil burial and composting techniques, with FTIR used to validate the degradation. The hydrogel degraded almost entirely within 64 days in compost soil and 72 days in burial soil. Finally, potassium dihydrogen phosphate release studies were conducted, and the data were analyzed using Fick’s law of diffusion and various kinetic models (zero order, first order, Higuchi, and Korsemers Peppas). The release pattern was measured via UV spectrophotometry over 45,000 min, demonstrating controlled nutrient delivery. These findings suggested that the synthesized hydrogel matrix has strong potential as an effective water retention system and for regulated nutrient release.

Using molecular dynamics modeling, the change in the conformational structure of the macromolecular corona consisting of two oppositely charged polyelectrolytes, including those combined into one block copolymer, on the neutral and charged surfaces of a cylindrical metal nanowire, as well as on a nanowire polarized in an external transverse uniform electric field is studied. A mathematical model of the conformations of polyelectrolyte chains and block copolymers adsorbed on charged and polarized cylindrical metal nanoparticles is presented. On the uncharged surface of the cylindrical nanowire, macromolecules of oppositely charged polyelectrolytes, including those sequentially connected into one block copolymer, intertwine with each other and form a tightly enveloping corona. On the uniformly charged surface of the nanowire, swelling of the macromolecular corona occurred due to its separation into differently charged coaxial macromolecular layers. When a metal nanowire was placed in an external transversely directed electric field, the macromolecular shell was stratified in the direction of the transverse polarization of the nanowire, and the charged layers of the polymer corona in the polar regions of the nanocylinder swelled.

In this research, a new guideline map has been introduced for the production process of acrylonitrile–butadiene–styrene (ABS) compounds in upstream units. Therefore, one-step mixing (method A) and two-step mixing (method B) in production of ABS composite were conducted and analyzed. On the other hand, introducing inorganic fillers during the final extrusion process in upstream units can result in complex behaviors of the ABS compounds, which are influenced by the positioning of the filler within the matrix. Therefore, the silane-modified wollastonite has been included in the ABS composites via two mixing methods and subsequently assessed. The findings indicate that the tensile modulus and the impact strength of composite containing a low level of wollastonite (5%) prepared by method B surpassed those obtained through method A. However, the observed results were inverted when the wollastonite content increased to 10%. At a low concentration of wollastonite, method A demonstrated a more significant transfer of filler into the butadiene rubber phase than method B. Conversely, at an elevated filler level, method B exhibited an increased extent of filler movement. The evaluated properties revealed that the mixing method significantly influences the improvement of the mechanical properties of the reinforced ABS composites. Nevertheless, additional research is crucial to comprehensively understand of the influence of mixing protocols on the microstructural characteristics of ABS composites.

Fe₃Se₄, 4c - Fe₇Se₈ and 3c - Fe₇Se₈ nanoparticles were synthesized using the solid-state reaction method, which was then incorporated into bisphenol A-epichlorhydrin epoxy resin to form nano-epoxy composites. The optical properties were analyzed using UV–visible spectroscopy, revealing a reduction in the optical band gap of the nanocomposites compared to neat epoxy, indicating enhanced light absorption and potential applications in optoelectronic devices. Fourier transform infrared spectroscopy (FTIR) was used to investigate the interactions between the nanoparticles and the epoxy matrix. In the radio wave frequency range, an increase in the ε′ was observed for the nanocomposites, which was attributed to polarization effects introduced by the nanoparticles. Microwave dielectric properties of the nanocomposites were characterized using a vector network analyzer (VNA), which was further utilized to assess their electromagnetic interference (EMI) shielding effectiveness. This study highlights the stable dielectric constant at microwave frequency and the dominance of absorption over reflection across the X band with an efficiency of approximately 8 to 9 dB. The findings suggest that Fe-Se nanoparticle-doped epoxy composites are promising materials for applications requiring enhanced optical, dielectric and EMI shielding properties.

Natural Fibre Polymer (NFP) and Polylactic Acid (PLA) composites have received a lot of interest in a variety of sectors because they are environmentally friendly, renewable, and sustainable. Over the last decade, researchers have investigated the aspects of NFP/PLA composite development and optimization for a wide range of applications, including packaging materials, automotive components, construction materials, textile and apparel, biomedical devices, agricultural and horticultural applications, electronics, and consumer electronics. Furthermore, using Artificial Intelligence (AI) and Machine Learning (ML) methodologies has increased these polymer materials and associated technologies in their search for new potential ways to further progress in NFP and PLA composites. The purpose of this review paper is to present a complete overview of AI and machine learning applications in the synthesis and development of NFP/PLA composite materials. The subject matter includes the following research areas: material characterization, manufacturing, property prediction, durability assessment, sustainability analysis, and future perspectives, which demonstrate the potential and challenges of AI/ML in advancing NFP/PLA composite materials and technologies.

The AA-AMPS-HPA terpolymer (acrylic acid—2-acrylamido-2-methylpropane sulfonate—hydroxypropyl acrylate) synthesis was carried out by means of a controlled one-step RAFT polymerization mechanism. The material was synthesized based on monomers with different functional groups considered environmentally friendly as they do not contain phosphorus in their structure. Optimal synthesis conditions were established, covering the following parameters: monomer concentration in the solution, RAFT agent and initiator concentration, temperature and reaction time. The characterization of the AA-AMPS-HPA copolymer included physicochemical analysis, structural analysis (FTIR, ¹H and ¹³C NMR) and evaluation of thermal properties (TGA and DSC). The rate of polymerization and monomer composition were calculated using NMR techniques. In the obtained polymer, the carboxylic groups compose the main chain, and these are complemented with sulfonates, amides, ester and hydroxyl groups which allow interacting with ions in the solution, precipitated salt molecules to halt and slow down the grow of inorganic salts. The terpolymer is stable around 100 ºC which is the maximum conditions expected for its use as an antiscalant agent. The terpolymer obtained showed a complete inhibition of calcium sulfate and calcium phosphate with 5 ppm and 30 ppm dosage respectively; in the case of calcium carbonate, a maximum inhibition value of 30% was obtained.

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An eco-friendly technique is developed for breaking down microplastic (MP) waste such as low-density polyethylene (LDPE), polyrpopylene (PP), polyvinyl chloride (PVC), and polyethylene terephthalate (PET) using nickel oxide (NiO) nanoparticles (NPs) made via sol–gel synthesis under sunlight. Many characterization techniques, including UV–vis DRS, FT-IR, XRD, HR-TEM, SEM–EDX analysis, XPS, GC–MS, and TGA analyses, were used to examine the optical and structural properties of materials synthesized using the sol–gel method. The findings of the degradation investigation indicate that the NiO/PET nanocomposites (NCs) films exhibited higher photocatalytic activity in comparison to the NiO/LDPE, NiO/PP, and NiO/PVC films. Because of their increased excellent suppression and optical absorption of photo-produced charge carrier recombination, NiO NPs exhibited greater photocatalytic degradation of PET films. PET films containing 2% weighted NiO NPs degraded by approximately 41.64% in just 30 days (240 h) under visible light in comparison to the NiO/LDPE, NiO/PP, and NiO/PVC NCs films. FT-IR study verified the production of carbonyl groups (-C = O) at 1725–1705 cm⁻¹ in the degradation products of LDPE, PP, PVC, and PET. The crystallinity and carbonyl indexes (CI) of the NiO/PET NCs films were as much as 30.0% lower than those of the NiO/LDPE, NiO/PP, and NiO/PVC films. The intermediate groups produced during the photodegradation of LDPE MPs were determined using GC–MS analysis. The major goal of this study is to provide an ecologically acceptable approach for photocatalytic degradation of MP waste using sol–gel synthesized NiO NPs.

PA6T/66 and PA5T/56 with stable molecular weight and molecular weight distribution were prepared by one-step polymerization. The relationship between the structure and physicochemical properties of two kinds of polyamide samples was analyzed by software analysis and instrument test. The results show that the hydrogen bond between molecular chains has a significant effect on the properties of the materials. From the microscopic point of view, the mechanical properties of PA5T/56 molecular model were generally better than those of PA6T/66 molecular model because the hydrogen bond was not considered. At the macro level, the result was just the opposite because of the hydrogen bonds between the molecular chains. The Gibbs free energy of PA5T/56 dehydration condensation reaction was larger, indicating that the polymerization rate was faster, which was consistent with the actual situation. PA6T/66 belongs to the triclinic α crystal system, PA5T/56 belongs to the hexagonal γ crystal system, PA6T/66 T_g = 105.50℃, T_c = 257.34℃, T_m = 295.74℃, the ΔG_PA6T/66 and ΔG_PA5T/56 = 36.84 kJ/mol and 34.27 kJ/mol respectively indicate that the heat resistance and thermal properties of PA6T/66 were better than those of PA5T/56.

Polyvinyl chloride (PVC) is widely used as a commodity plastic in various industries and daily life. However, its green development is limited due to the fact that most plasticizers are either toxic or derived from food products. This study examines the plasticizing mechanisms by comparing three ricinoleic acid esters with different alkyl chain lengths to three commercial plasticizers, including dioctyl terephthalate (DOTP), epoxidized soybean oil (ESO), acetyl tri-n-butyl citrate (ATBC). The results indicate that ester bonds with higher polarity can readily penetrate PVC’s polar barrier and integrate into the polymer chain, while epoxy groups with lower polarity enhance chain stability. Moreover, benzene rings contribute to molecular stability and expand chain spacing. The length of the alkyl chain significantly influences the properties of structurally similar molecules: longer alkyl chains demonstrate greater resistance to migration and improved thermal stability, whereas shorter alkyl chains exhibit better plasticizing effects. Additionally, these ricinoleic acid plasticizers exhibit performance characteristics similar to those of commercial plasticizers in several aspects, underscoring the significant application potential of non-edible ricinoleic acid as a viable candidate to address the sustainability challenges of PVC materials.

Environmentally sustainable composites reinforced with sugarcane bagasse fiber (SBF), a natural fiber derived from the residual biomass of sugarcane processing, were developed using four polymer matrices: unsaturated polyester resin (UPR), bio-epoxy (BE), polylactic acid (PLA) and high-density polyethylene (HDPE). SBF content was varied at 3 wt%, 6 wt% and 9 wt%. Thermosetting composites were prepared using the open casting method, while thermoplastic composites were fabricated through compression molding. The study assessed physical and mechanical responses to elucidate the influence of matrix type and fiber loading. Composite density and properties like tensile modulus, flexural modulus, hardness and toughness improved with increasing fiber content, while tensile strength, elongation at break, flexural strength and flexural strain declined. Moisture susceptibility rose with higher fiber content, highlighting a trade-off between reinforcement and durability. Notably, 3 wt% BE composites exhibited superior tensile strength, 6 wt% BE had the highest tensile modulus and impact strength, 3 wt% PLA achieved peak flexural strength, 9 wt% PLA showed the greatest flexural modulus and 6 wt% PLA displayed the highest shore D hardness. These findings provide critical insights for optimizing polymer-fiber systems in sustainable composite design.