Polymer Filler Research Articles

Simultaneous Toughening and Strengthening of Ductile Polymer by Rigid Polymeric Fillers: The Role of Interfacial Entanglement.

The modification of thermoplastic polymers is frequently impeded by the inherent contradiction between their toughness and strength. In this study, an effective strategy to significantly improve the mechanical properties of ductile polymers by simply adding a complimentary rigid polymer is introduced. This work uses a semi-crystalline polymer aliphatic polyketone (POK) as the matrix material and a small quantity of polymethyl methacrylate (PMMA) as the rigid polymer, through establishing molecular chain entanglements at the interface to produce POK/PMMA blends with exceptional mechanical property. The experimental study shows that PMMA as a small island phase is homogeneously dispersed in the POK matrix, while the interfacial adhesion between the POK matrix and PMMA island is enhanced by the high-density molecular chain entanglement between PMMA and the POK matrix. The strong entanglements and high concentration of PMMA domains promote uniform crazes and overall shear yielding. As a result, the POK/PMMA blend exhibits exceptional mechanical properties with notched impact strength, elongation at break, tensile strength, and Young's modulus, of 20kJm-2, 326%, 60 and 2185MPa, respectively. A universal approach is further suggested for enhancing the toughness and strength of ductile polymers using a complimentary rigid polymer.

Ecologic and economic motives for transforming calcium-based food wastes into sustainable value-added products: a review.

An overview of various industrial and bio-applications of unavoidable bio-waste materials reported in the literature over the last 25years is presented in this review. Calcium-based food wastes or "unavoidable bio-wastes" are hybrid bio-composite materials, consisting of a softer organic matrix surrounding a stiff mineralized ceramic phase. A wide range of different bio-wastes that are already in use or are investigated for multipurpose applications are presented. Bio-wastes hold considerable potential to contribute more widely to the circular management strategy through, for example, being processed to make new consumer products for a variety of applications, which include the use as a filler in polymers, biogenic hydroxyapatite, limestone or lime in construction products, nutritional feed supplements, soil-improving material and fertilizer, or precursor for making catalysts and adsorbents for the remediation of environmental contaminants. This review summarizes the results of various reported approaches with regard to the development of cost-effective value-added products from under-utilized food waste residues such as eggshells, seafood shells, and animal bones via a simple, eco-friendly, and economically viable approach. Therefore, the work is an advancement toward the goal of achieving a sustainable product by ensuring a holistic design approach from bio-wastes to various salable products, where calcium-based food wastes can compete with non-renewable resources.

Influence of Graphene Oxide on Printability, Rheological and Mechanical Properties of Highly Filled Alumina Filaments and Sintered Parts Produced by FFF

The aim of the study was to investigate the effect of the addition of graphene oxide (GO) on the rheological and mechanical properties of extruded polyamide 12 (PA12) filaments with high aluminum oxide (Al2O3) content used for 3D printing using the fused filament fabrication (FFF) method. Firstly, Al2O3-based mixtures with 0.10, 0.25 and 0.50 vol.% GO content were prepared. These mixtures were dried and subsequently combined with paraffin wax (PW), stearic acid (SA) and polyamide 12 (PA12) in an organic solvent. After drying in a vacuum oven and sifting, powder compositions of 74 wt.% (Al2O3 + GO)/26 wt.% (PA12 + PW + SA) with different GO content were obtained. All compositions were successfully extruded into filaments for 3D printing. Rheological, microstructural and mechanical studies of the compositions and filaments were carried out. X-ray diffraction phase analysis and Raman spectroscopy were also performed. It was shown that 0.10 and 0.25% vol. GO proved to be a universal additive that resulted in an increase in the rheological and mechanical properties of the highly filled polymer and also improved its 3D printability, which ultimately helped obtain a ceramic product with complex shape using the FFF method.

Mathematical Modeling of Load Capacity and Durability of Metal-Polymeric Bearings with a Composite Bushing Based on Polyamides, Polytetrafluoroethylenes, Polyetheretherketones, or Polyethylene Terephthalates

Predictive assessments of the performance characteristics of metal-polymer (MP) plain bearings at the design stage are necessary and important for engineering practice. They include assessments of bearing capacity, linear wear of the bushing, and bearing life. However, no method for their calculation has been developed. The authors created a generalized analytical method for the mathematical modeling of MP sliding bearings as a classical science-based method to study the contact mechanics of conformal cylindrical bodies with consideration of polymer bushing wear. The contact problem of the theory of elasticity takes into account the significant difference in the elasticity characteristics of polymeric materials from those of steel: their Young’s modulus is 60–250 times smaller, and Poisson’s ratio is 1.27–1.37 times larger. The method was used to study MP bearings with bushings made from several common groups of tribopolymers: polyamides (PAs), polytetrafluoroethylenes (PTFEs), polyethylene terephthalates (PETs), and polyetheretherketones (PEEKs). The maximum contact pressures and durability of the dry friction bearings were calculated while taking into account the load; radial clearance; bushing thickness; the tribopolymers’ elasticity characteristics and wear resistance; the sliding friction coefficient; and the type of tribopolymer material. The Young’s modulus of a polymer material had a significant impact on the level of maximum contact pressures. Polymer fillers, depending on their type and the type of polymer, had very different effects on pressure changes (increase, no change, or decrease). An increase in pressure caused an increase in contact pressures. The durability of a mechanical bearing depended not only on the contact pressure but also on the polymer’s wear resistance, Young’s modulus, and friction coefficient. This study determined the quantitative and qualitative effects of these factors on the maximum contact pressures and bearing durability. The presented analytical method provides an effective and reasonable assessment of the specified service characteristics of sliding bearings with consideration of the multifactorial influence of the above factors.

Mechanical performance of polyurethane polymer mortar—A novel sealing material for CAES man-made caverns

This work aims to investigate the feasibility of polyurethane polymer mortar (PPM) as a sealing material for compressed air energy storage (CAES) caverns. The effect of polymer content, aggregates ratio (fine sand to medium sand) and filler types (bentonite, clay, and fly ash) on gas permeability, tensile strength, and resistance to high and low temperature of PPM were conducted. The scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were performed to characterize the microstructure of PPM. Additionally, numerical simulations were performed to analyze the stress distribution characteristics of PPM when used as a sealing structure. The results demonstrate that PPM exhibits low gas permeability (10−21 m2), high tensile strength (up to 2.96 MPa), and significant tensile strain (up to 27.02 %), with a relatively low elastic modulus (11.87–35.05 MPa). Meanwhile, PPM containing fly ash showed the highest strength, followed by those with clay, while PPM with bentonite exhibited the lowest strength. However, only the PPM with bentonite as a filler remained stable and did not collapse under high temperatures. The hoop stresses in the PPM are only compressive and not tensile, and the maximum hoop tensile strain remains well below the ultimate tensile strain of the material, thus preventing the tensile damage and ensuring the gas-tightness. These findings provide a theoretical basis for using PPM in CAES sealing applications, and advance the understanding and application of sealing materials in CAES man-made caverns.

Electrochemical Properties of Solid Electrolytes with High Content of Non-Sintered Ceramics

1.IntroductionAll-solid-state lithium-ion batteries are rechargeable batteries that use either polymeric or inorganic solid ionic conductor as the electrolyte1). All-solid-state lithium-ion batteries with solid polymer electrolytes have long been investigated because of their ease of handling. There are two types of solid polymer electrolytes currently under consideration: gel-based and dry types2). Gel type has high ionic conductivity because this is swollen by organic solvents, but safety is compromised due to leakage of organic solvents. On the other hand, dry type does not use organic solvents, so there is no risk of leakage, but that has lower ion conductivity than gel type. In response to this problem, research was conducted to improve ion conductivity by adding inorganic filler to the dry system for making it amorphous2); however, the improvement in ion conductivity was not sufficient because an inorganic filler has no ionic conductivity. In this study, therefore, a new composite solid electrolyte with higher ionic conductivity than that of conventional solid electrolytes was prepared by using an inorganic oxide solid-state electrolyte (ISE) as an inorganic filler in a dry polymer. its electrochemical properties were also investigated.2.ExperimentalTo prepare the composite solid electrolyte, an inorganic filler dispersion was prepared by dispersing LICGC (PW-01, Ohara) as ISE and 3-aminopropyltriethoxysilane as dispersing agent in tetrahydrofuran. The inorganic filler dispersion was combined with polycaprolactone (PCL) and lithium bis(fluorosulfonyl)imide (LiFSI) to prepare a LICGC slurry. The LICGC slurry was dried at 40°C for 12 hours and then pressurized to prepare PCL-LICGC (150 μm film thickness). Instead of PCL, polylactic acid (PLA) and polyethylene oxide (PEO) was applied for preparing PLA-LICGC and PEO-LICGC for comparison. A Li symmetric cell was fabricated to measure the ionic conductivity of each LICGC, and their ionic conductivity and activation energy during the ion transfer process at 25-55°C were evaluated. The electrochemical properties of each LICGC were also investigated using the Li symmetric cell, and charge-discharge measurements were performed at different current densities. The fabricated composite solid electrolytes are indicated with the name of the polymeric material used in this section and the content of LICGC at the end of the name sequence.3.Results and discussionPCL-LICGC50, PLA-LICGC50, and PEO-LICGC50 showed 2.12 × 10-4, 1.22 × 10-5, and 4.32 × 10-7 S cm-1 at 25°C, respectively, indicating that PCL-LICGCs have higher ionic conductivity than the other LICGCs; the ionic conductivity of PCL-LICGC50 was found to be higher than that of other composite electrolytes. In addition, PCL-LICGC50 showed 4.5 times higher ionic conductivity than PLA-LICGC50, an ester-based polymer of the same genus. This is due to the lower activation energy of PCL-LICGC50 in the ion transfer process and the higher diffusion rate of Li⁺ in the LICGC than that of PLA-LICGC50.PCL-LICGC50 can be charged and discharged stably at current densities of 0.177 mA cm-2 for more than 600 hours and 0.354 mA cm-2 for more than 60 hours, respectively. Conventional inorganic solid electrolytes were stable at 0.177 mA cm-2 for more than 600 hours. These results indicate that the PCL-LICGC50 fabricated in this study has better charge-discharge characteristics than the conventional solid electrolytes. On this presentation, we will report the variations in ionic conductivity and activation energy when the composition ratio of LICGC is changed, as well as charge-discharge characteristics under a high current density.4.AcknowledgmentsPCL and PLA used in this study were provided by Toagosei Co., Ltd.5.References1) J. Wen et al., Mater. Express, 2, 197 (2012).2) J. Feng et al., Nano Converg., 8, 2 (2021).

Strong and Flexible PEO/Pvdf Polymer Composite Electrolyte for All Li Metal Solid-State Battery

The state-of-the-art Li-ion battery has energy density plateauing at ~300 Wh/kg [1]. Replacing the graphite-based anode with Li metal is one promising pathway to increase energy density. However, a lithium metal anode is prone to non-uniform plating/striping that leads to capacity decay and dendrite formation. Solid-state batteries (SSBs) hold great promise for next-generation energy storage systems due to their potential to address safety concerns, provide energy density, and enable the use of high-energy electrode materials such as lithium (Li) metal. Additionally, SSBs exhibit greater mechanical stability and can limit dendritic growth [2]. Furthermore, solid electrolytes show much higher thermal stability, are non-toxic, and have high energy density. Among the various types of solid-state electrolytes, composite polymer electrolytes (CPEs) have emerged as a promising option owing to their excellent ionic conductivity, mechanical flexibility, and compatibility with Li metal electrodes. Polyethylene oxide (PEO) polymer electrolyte has very good interfacial contact between electrode and very flexible in nature [3]. But PEO by itself is unstable. A PEO composite with solid ceramic offers the potential for better stability with high conductivity as well as improved physical properties.Our research focuses on elucidating key parameters that affect the electrochemical behavior and stability of these systems, aiming to enhance their overall performance and longevity. One of the primary factors under investigation is the composition and morphology of the composite polymer electrolyte. We explored PEO polymer and LLZTO ceramic fillers to optimize the electrolyte's mechanical strength, Li-ion conductivity, and interfacial stability with Li metal electrodes [2]. Through systematic characterization techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and impedance spectroscopy, we gain insights into the microstructure and ion transport properties of the CPE.The combination of PEO and Polyvinylidene fluoride (PVdF) polymer creates a remarkably robust and flexible polymer electrolyte, renowned for its exceptional mechanical and electrochemical stability. Figure 1 (a) shows the cycling profile of PEO/PVdF electrolyte at different C rates with LFP cathode and Li metal as anode. Compared to PEO membrane, the composite exhibits higher ohmic polarization. However, this composite polymer electrolyte demonstrates better stability and high-rate capability than a pure PEO membrane. At 1-C rate charging and discharging condition cell shows 99% columbic efficiency and good capacity retention. In Figure 1(b) and (c) show the SEM image of PVdF and PEO composite membrane respectively. Which shows PEO completely covers the PVdF network and helps better contact with solid electrode.Reference: Bapi Bera, Anirban Roy, Douglas Aaron, and Matthew M Mench, “Understanding the Transport Phenomena in Solid State Battery (SSB)”, Electrochemical Society Meeting s-241, 2022, 1, 45-45.Yanda Fu et al., “Surface Defects Reinforced Polymer-Ceramic Interfacial Anchoring for High-Rate Flexible Solid-State Batteries”, Adv. Funct. Mater. 2023, 33, 2210845.Sahore, Z. Du, X. C. Chen, W. B. Hawley, A. S. Westover, and N. J. Dudney, Practical considerations for testing polymer electrolytes for high-energy solid-state batteries, ACS Energy Lett. 2021, 6, 2240-2247. Figure 1

Extrusion-Based Additive Manufacturing of WC-10Co Cemented Carbide Produced with Bimodal Ultrafine/Micron WC Particles

This article researches the effect of ultrafine (submicron) tungsten carbide powder addition on the microstructure and mechanical properties of WC-10Co cemented carbide produced by the extrusion of a highly filled polymer. This addition aims to develop a material with a good combination of toughness, hardness, and yield strength. The results demonstrate that increasing the ratio between ultrafine and micron WC particles from 0/100 to 45/55 in the initial powder results in successive decreases in average grain size from 2.61 µm to 1.75 µm. When 45% of ultrafine powder is introduced into the mixture, a high number of fine tungsten carbide grains is produced. This promotes inter-grain contact and reduces the free path of the binder phase, which results in a more rigid structure and in the material becoming more brittle. The best mechanical characteristics are achieved in WC-10Co cemented carbide with 15% content of ultrafine powder in the total weight of WC. Here, a microstructure with a bimodal distribution of tungsten carbide grains in a virtually non-intermittent cobalt phase was formed. This allowed us to achieve a compressive strength of 2449 MPa at the deformation of 6.69%, while the modulus of elasticity was 38.8 GPa. The results indicate a good combination of strength and ductility properties in the developed cemented carbide.

Advanced Mullins Damage Modeling (AMDM) after Multiple Cyclic Loading in Vulcanizates; Part 1: Theory and Parameter Identification

Abstract This study explores the deformation behavior of carbon black-filled elastomeric components under multiple cyclic loading conditions. Understanding the effects of repeated cyclic deformation is crucial for accurate Finite Element Method (FEM) simulations. We present an approach that captures both initial and subsequent cycles, converging to an equilibrium state. Experimental evidence from cyclic deformation and relaxation tests indicates that an equilibrium state is achieved within five deformation cycles. Our method analytically describes the relaxed or equilibrium state after multiple cyclic deformations by combining a relaxation model with a material model. We utilized a combination of a relaxation approach and the Modified Extended Tube Model (METM), allowing us to distinguish between polymer network effects and filler properties, thereby establishing a direct correlation between elastomer parameters and mechanical properties. The multiple cyclic deformation behavior can be analytically described using the Advanced Mullins Damage Modeling (AMDM) approach, validated through experimental data. The AMDM employs two damage functions for the increasing and decreasing stress phases of the cycle using the relaxed METM approach. The feasibility of this approach is demonstrated through 3D finite element (FE) simulations, confirming the validity of AMDM under cyclic deformation. The combination of the relaxed METM and AMDM approaches provides a robust framework for predicting the cyclic deformation behavior of filled elastomers, with significant applications in engineering and material science.

Preparation of Activated Carbon- and Graphite-Coated Banana Fibers as Flame-Retardant Materials

In polymer studies, biocomposite now draws attention as an exciting material obtained from combining natural fiber and matrix, which is an environmentally friendly material with biodegradable properties. One of the natural fibers often used in polymer filler is banana stem fiber. This study aims to prepare carbon-coated waste-dried banana fiber. The waste of banana stems was used as raw material for preparing cellulose-rich banana stem fiber. The banana fiber was soaked in an alkaline solvent, 1% NaOH, to remove the lignin content. The dried banana fiber was then coated with activated carbon and graphite by immersion in the carbon dispersion in ethanol with PVA glue binder added. Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) spectra show different profiles on raw and carbon-coated banana fibers, indicating successful carbon coating. The burning test and thermal analysis results show that carbon-coated banana fibers have better thermal properties than raw banana fiber. This suggests that carbon covered on the fiber surface could enhance its thermal property due to intramolecular bonds between fibers and carbon particles. Graphite-coated banana fibers have the longest burning time and are concluded to have the best fire-retardant properties among all samples. The findings confirmed the potential use of carbon-coated banana fiber as filler material for reinforcing conventional composites.

Preparation and properties of polymer composites filled with modified highly dispersed polyethylene terephthalate

A new method of processing polyethylene terephthalate waste into a highly dispersed polymer filler by chemical treatment in an aqueous ammonia solution has been proposed. The possibility of obtaining highly dispersed polymer filler and polymer composite materials under elevated pressure and temperature by incorporating the filler into an epoxy oligomer has been demonstrated. The size and microphase structure of dispersed modified polyethylene terephthalate were determined using optical microscopy and speckle interferometry. Infrared spectroscopy established the presence of polyamide groups on the surface and preserved polyethylene terephthalate in the center of the particles. The use of 2-(tri-butoxymethyl)oxirane monoepoxide demonstrated that the resulting powder is an active filler and reacts with epoxy groups at elevated temperature, enhancing the strength of the composite after formation. Some operational characteristics of the polymer composites have been determined, and the feasibility of applying the proposed methods to address the disposal of PET containers, including plastic bottles, has been shown. The conditions for producing the fillers, along with the characteristics of the obtained fillers and the polymer composites based on them, have been established.

Preparation and Characterization of Magnetic Polymeric Micro- and Nanocomposites for Industrial Applications

ABSTRACT To optimize cost and weight and streamline the manufacturing process of existing soft magnetic components, which currently rely on metallic soft magnetic particles, an innovative approach involving the preparation of high-performance magnetic polymeric composites is proposed. These composites are based on soft magnetic ferrite particles with high Curie temperature and magnetic saturation, along with low coercivity and remanent magnetization, and are used as fillers in thermoplastic polymers. To achieve these goals, cobalt ferrite (CoFe2O4) micro- and nanoparticles were synthesized by two different methos: solid-state reaction and coprecipitation. The as-obtained particles were used to fabricate soft magnetic polymer composites by extrusion and injection molding methods. The successful synthesis of cobalt ferrite was confirmed by X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. The magnetic behavior of cobalt ferrites and polymer composites was also investigated by vibrating sample magnetometry (VSM). This study shows that these new high-performance soft magnetic polymer composites can be used as alternative materials for the manufacture of magnetic components such as inductors and transformers and that their low cost and lightweight make them suitable for the manufacture of magnetic components.

Progress on the Sound Absorption of Viscoelastic Damping Porous Polymer Composites.

Porous polymer composites (PPC) have developed rapidly recently, which are widely used in various industrial fields. Viscoelastic damping is an important behavior of porous polymer composites, and it can determine the sound absorption for noise reduction applications. This review has mainly covered the viscoelastic damping and sound absorption of porous polymer composites. Different fabrication approaches of porous polymer composites are gathered. The mechanism of viscoelastic damping behavior is described, and also the sound absorption properties. Followed by the introduction of enhanced sound absorption of viscoelastic damping porous polymer composites, including the incorporation of fillers, microstructures modification, combination with nanofibrous materials, and multilayer configuration, etc. The incorporated fillers can effectively adjust the interfacial area in composites, and obtain desired bonding conditions. Microstructures modification is an effective tool to improve the morphologies of both polymer matrix and fillers, which can be achieved by chemical treatment and surface coating. The combination with lightweight nanofibrous layer can increase the low frequency absorption. The configuration of multilayer composites can improve both acoustical and mechanical properties for engineering applications. It is hoped that this comprehensive review is benefit for the promising development of porous polymer composites in related fields.

Investigation of mixed matrix membranes of graphene and acid‐treated graphene fillers in cellulose acetate and polyetherimide polymers for CO2 separation from biogas

AbstractGas separation membranes are crucial for upgrading biogas by separating carbon dioxide (CO2) from biogas, thereby enhancing its calorific value and reducing greenhouse gas emissions. This study aims to improve CO2/CH4 separation using mixed‐matrix membranes (MMMs) by incorporating graphene (Gr) and acid‐treated graphene (AGr) fillers in a cellulose acetate (CA) polymer matrix. Similarly, polyetherimide (PEI) MMMs were also prepared with Gr and AGr fillers to draw a comparison. Various characterization techniques, including Fourier transform infrared spectroscopy, differential scanning calorimetry, field emission scanning electron microscopy, Raman spectroscopy, and X‐ray diffraction, were employed to investigate the structural and morphological properties of the membranes and fillers. Gas permeation tests using a model biogas mixture (40% CO2 and 60% CH4) revealed that the 0.1%AGr/CA membrane achieved the highest CO2 permeability of 43 Barrers, which is approximately 307% more than that of the pure CA membrane, and showed a CO2/CH4 selectivity of 14.80. The 0.5%Gr/PEI membrane demonstrated the best performance among PEI‐based MMMs, with a CO2 permeability of 17.48 Barrers and a CO2/CH4 selectivity of 8.96. These results indicate that the incorporation of Gr and AGr significantly enhances the gas separation performance over pure CA and PEI membranes.Highlights Graphene (G) and acid‐treated Gr‐based cellulose acetate (CA) and polyetherimide (PEI) mixed‐matrix membranes (MMMs) were fabricated. Model biogas was used for testing CO2 and CH4 gas permeation. The 0.1% AGr/CA MMM showed 307% higher CO2 permeability than pure CA. The 0.5% Gr/PEI MMM showed 435% higher CO2 permeabilit than pure PEI. Structural properties were confirmed by Fourier transform infrared spectroscopy, differential scanning calorimetry, field emission scanning electron microscopy, Raman, and X‐ray diffraction.

Synergistic enhancement of magic triangle properties of PC tread stocks modified by amine-capped trans-1,4-poly (butadiene-co-isoprene)

The development of high-performance “green tires” with synergistically improved “magic triangle” properties like lower rolling resistance, higher wet-skid resistance and higher abrasion resistance has always been a hot issue. In this work, an effective strategy for developing high-performance “green tires” with simultaneously improved “magic triangle” properties of solution-polymerized styrene-butadiene rubber (SSBR)/cis-1,4-polybutadiene rubber (BR) nanocomposites modified by amine-capped trans-1,4-poly(butadiene-co-isoprene) copolymers (F-TBIR) was proposed. A series of F-TBIR with 10–60 mol% amine-capped efficiency (CE) and 30-90 × 104 weight-average molecular weight (Mw) were synthesized by using heterogeneous TiCl4/MgCl2–Al(i-Bu)3 Ziegler-Natta catalyst with dicyclohexylamine (DCHA) as chain transfer agent (CTA). With the increase in CE of F-TBIR, the silica-filled SSBR/BR/F-TBIR compounds exhibited improved green strength, modulus at 100 % elongation and bound rubber, and their vulcanizates showed synergistically improved “magic triangle” properties like obviously reduced rolling resistance and abrasion loss, and increased wet-skid resistance. It was found that the incorporation of 10 phr F-TBIR3 with CE of 60 mol% and Mw of 32 × 104 resulted in highly expected properties of the SSBR/BR/F-TBIR3 nanocomposite. The contribution mechanism of F-TBIR3 was discussed based on the improvements of polymer network structures and filler network structures. This work is expected to provide an effective strategy to construct the desired network structures for high-performance rubber composites.

Enhanced Dielectric, Thermal, Energy Storage, Quality Factor, Impedance, and Conductivity Properties of Novel PVDF/PAN/ZrO2 Polymer Nanocomposites for Flexible Electronics Applications

ABSTRACTIn this study, novel polymer nanocomposite films based on polyvinylidene fluoride/polyacrylonitrile/zirconium dioxide (PVDF/PAN/ZrO2) were prepared using a solution casting technique. The structural modifications and morphological properties were analyzed by x‐ray diffraction (XRD) and high resolution scanning electron microscopy (HRSEM). The obtained results verified the filler‐polymer interactions and uniform dispersion of the ZrO2 filler in the host polymers (PVDF and PAN). Thermal stability of up to 46% leftover residue for 30% ZrO2 nano‐filler loading in the blend polymer nanocomposite was analyzed by thermogravimetric analysis (TGA). The dielectric properties such as dielectric constant and dielectric loss values and impedance, Q‐factor, and AC conductivity were analyzed using an impedance analyzer. The decrement in impedance with increasing nano‐filler content with improved dielectric, thermal, Q‐factor, energy density and conductivity properties signifies the prepared novel PVDF/PAN/ZrO2 polymer nanocomposite as an effective material for flexible electronics applications.

Tailoring the size and shape of PbWO4 particles in highly filled polymer fibers for γ‐rays shielding

AbstractHighly filled polymer fibers offer huge promise for radiation protection safety and wear comfort of personal protective equipment (PPE) in radiation environments. However, it usually sacrifices mechanical properties that directly related to practical usability. Here, as high as 75 wt% PbWO4 (PWO) particles have been filled in polyvinyl alcohol (PVA) fiber via tailoring their size and shape for enhanced γ‐rays shielding and good mechanical properties. Clearly shown that 0 dimensional (0‐D) PWO exhibits better dispersion and compatibility between the interfaces than 1‐D PWO in highly filled PVA fibers. In addition, 70 wt% 0‐D PWO/PVA fibers display better mechanical properties than 70 wt% 1‐D PWO/PVA fibers. Note that 75 wt% 0‐D PWO/PVA fibers show 1.02 cN/dtex of tensile strength. However, 75 wt% 1‐D PWO/PVA fibers fail to be fabricated smoothly. Importantly, the overlapped fabrics with 75 wt% 0‐D PWO/PVA fibers display 43.05% of γ‐ray shielding (105 keV) meanwhile it offers good air and water vapor permeability for wear comfort. The superior γ‐ray shielding ascribes the polymer fibers with the higher filling in comparison with its counterpart, which provides a practical means to design radiation protection safety and wear comfort of articles.Highlights This work breaks the upper limit of filling in polymer fibers Filler structure can weigh the integrated properties of polymer fibers. 0‐D PWO particles promote interfacial compatibility in highly filled fibers. Radiation protection safety and wear comfort of articles tend to be designed.

Central Role of Filler–Polymer Interplay in Nonlinear Reinforcement of Elastomeric Nanocomposites

Central Role of Filler–Polymer Interplay in Nonlinear Reinforcement of Elastomeric Nanocomposites

Moisture sorption and mechanical properties of polymer-cement waterproofing membranes investigated by LF NMR

This study investigates the impacts of environmental humidity on moisture absorption and mechanical properties of polymer-based waterproofing membranes. Membranes of polymer-CaCO3, polymer-white cement composites and pure polymer were used for measurements after treated in different relative humidities (RHs). Results indicate that the humidity treatment greatly changes the mechanical properties of the membranes and increasing RH from 0 % to 100 % leads to reduction of tensile strength by 60–80 %, which is believed to originate from the plasticizing effect of the absorbed moisture. LF NMR (Low field NMR) enables quantification of moisture distribution in the polymer-filler composites and three types of water, i.e. the water stored inside polymer matrix (O/O water), the water located in interfacial regions between polymer phase and fillers (I/O water), and the free water in air voids are detected with increasing T2 values. The absorbed moisture majorly accumulates in the O/O interfacial region during the humidity treatments with RH of 0∼80 %, which is because of the larger O/O interfacial area compared with the I/O interface. A large amount of free water appears only at RH of 100 %. A core-shell structure of the polymer domains with dry core and moisturized shell, is interestingly found during the moisture absorption process of the membranes, based on the LF NMR measurements using MSE sequence. It is surprisingly found that the drop of tensile strength of the membranes upon moisture absorption is majorly related to the growing shell thickness of the polymer domains whereas the moisture accumulated in the I/O interfacial region plays a minor role.

Finite Element Analysis of the Structure and Working Principle of Solid-State Shear Milling (S3M) Equipment.

Solid-state shear milling (S3M) equipment is an evolution from traditional stone mills, enabling the processing of polymer materials and fillers through crushing, mixing, and mechanochemical reactions at ambient temperature. Due to the complex structure of the mill-pan, empirical data alone are insufficient to give a comprehensive understanding of the physicochemical interactions during the milling process. To provide an in-depth insight of the working effect and mechanism of S3M equipment, finite element method (FEM) analysis is employed to simulate the milling dynamics, which substantiates the correlation between numerical outcomes and experimental observations. A model simplification strategy is proposed to optimize calculation time without compromising accuracy. The findings in this work demonstrate the S-S bond breakage mechanism behind stress-induced devulcanization and suggest the structural optimizations for enhancing the devulcanization and pulverization efficiency of S3M equipment, thereby providing a theoretical foundation for its application in material processing.