Polymer Filler Research Articles

Radiolytic modification of polymer filler for cement compositions

Radiolytic modification of polymer filler for cement compositions

Optimization Course of Titanium Nitride Nanofiller Loading in High-Density Polyethylene: Interpretation of Reinforcement Effects and Performance in Material Extrusion 3D Printing.

In this study, titanium nitride (TiN) was selected as an additive to a high-density polyethylene (HDPE) matrix material, and four different nanocomposites were created with TiN loadings of 2.0-8.0 wt. % and a 2 wt. % increase step between them. The mixtures were made, followed by the fabrication of the respective filaments (through a thermomechanical extrusion process) and 3D-printed specimens (using the material extrusion (MEX) technique). The manufactured specimens were subjected to mechanical, thermal, rheological, structural, and morphological testing. Their results were compared with those obtained after conducting the same assessments on unfilled HDPE samples, which were used as the control samples. The mechanical response of the samples improved when correlated with that of the unfilled HDPE. The tensile strength improved by 24.3%, and the flexural strength improved by 26.5% (composite with 6.0 wt. % TiN content). The dimensional deviation and porosity of the samples were assessed with micro-computed tomography and indicated great results for porosity improvement, achieved with 6.0 wt. % TiN content in the composite. TiN has proven to be an effective filler for HDPE polymers, enabling the manufacture of parts with improved mechanical properties and quality.

ФИЗИКО-ХИМИЧЕСКИЕ СВОЙСТВА ПОЛИМЕРНО-БИТУМНЫХ ВЯЖУЩИХ, МОДИФИЦИРОВАННЫХ ШУНГИТОМ РАЗЛИЧНЫХ МЕСТОРОЖДЕНИЙ КАРЕЛИИ

The use of polymer-bitumen binders as part of an asphalt concrete mixture allows to improve the quality of road surfaces. The most commonly used polymer is styrene and butadiene copolymer, however, it does not provide sufficient durability of asphalt concrete and has a high cost. There is a positive experience in solving these problems through the use of polymer composites filled with fine powders. One of the promising polymer fillers is shungite. The purpose of this work was to study the effect of shungite from various deposits of Karelia on the structure and properties of polymer-bitumen binder. It was found that the introduction of shungite in the amount of 5 wt.% changes the physico-chemical characteristics of polymer-bitumen binders: the viscosity and softening temperature increase markedly, the temperature of brittleness, as well as extensibility and elasticity change to a lesser extent. Changes in these properties indicate the structuring of the binder by finely dispersed shungite. This phenomenon may be associated with the transfer of bitumen from a volumetric to a structured state due to its interaction with the surface of the shungite powder, as well as due to the diffusion of low-molecular components of the binder into the pores of the filler. Moreover, shungite samples from different deposits do not affect the studied characteristics in the same way. The explanation for this may lie in the different content of active adsorption centers on the surface of shungite, which is in a linear relationship with the main characteristics of the polymer-bitumen binder modified with shungite.

Influence of wax addition on feedstock processing behavior in additive manufacturing of metals by material extrusion

The additive manufacturing of metals by material extrusion in a multi-step process (MEX-MSt/M) represents a special process variant of the commonly used material extrusion (MEX) and is based on the processing of highly filled polymer filaments. This technology uses the geometrical freedom and fast processing given by MEX to create individual metal parts after a debinding and sintering process in a cost and time-efficient way. The filaments for MEX-MSt/M are made by incorporating metal powders, such as aluminum, stainless steel, or bronze into a polymer matrix. Due to the challenges that are assigned to the processing of highly filled polymers, like the increased viscosity of the material or clogging of the nozzle, the binder materials have to meet several requirements. Therefore, waxes are often used to enable a better extrusion behavior for MEX; however, the addition of wax also affects other crucial processing properties of the filaments. In this work, the interactions of different types and amounts of waxes on thermal, mechanical, and rheological properties were investigated to create a better understanding of the alternating effects of wax addition into highly filled filaments for processing via MEX. The study demonstrated that an increase in wax contents resulted in both a significant decrease in ductility and an overall improvement in melt flowability. The choice of waxes also affected the particle–matrix interactions, partly leading to an improved wetting of the filler particles.

Filled Elastomers: Mechanistic and Physics-Driven Modeling and Applications as Smart Materials.

Elastomers are made of chain-like molecules to form networks that can sustain large deformation. Rubbers are thermosetting elastomers that are obtained from irreversible curing reactions. Curing reactions create permanent bonds between the molecular chains. On the other hand, thermoplastic elastomers do not need curing reactions. Incorporation of appropriated filler particles, as has been practiced for decades, can significantly enhance mechanical properties of elastomers. However, there are fundamental questions about polymer matrix composites (PMCs) that still elude complete understanding. This is because the macroscopic properties of PMCs depend not only on the overall volume fraction (ϕ) of the filler particles, but also on their spatial distribution (i.e., primary, secondary, and tertiary structure). This work aims at reviewing how the mechanical properties of PMCs are related to the microstructure of filler particles and to the interaction between filler particles and polymer matrices. Overall, soft rubbery matrices dictate the elasticity/hyperelasticity of the PMCs while the reinforcement involves polymer-particle interactions that can significantly influence the mechanical properties of the polymer matrix interface. For ϕ values higher than a threshold, percolation of the filler particles can lead to significant reinforcement. While viscoelastic behavior may be attributed to the soft rubbery component, inelastic behaviors like the Mullins and Payne effects are highly correlated to the microstructures of the polymer matrix and the filler particles, as well as that of the polymer-particle interface. Additionally, the incorporation of specific filler particles within intelligently designed polymer systems has been shown to yield a variety of functional and responsive materials, commonly termed smart materials. We review three types of smart PMCs, i.e., magnetoelastic (M-), shape-memory (SM-), and self-healing (SH-) PMCs, and discuss the constitutive models for these smart materials.

Influence of process parameters on the occurrence of defects and dimensional properties of green part produced by material extrusion of highly filled polymer

Influence of process parameters on the occurrence of defects and dimensional properties of green part produced by material extrusion of highly filled polymer

Surface Modification of Nano-Hydroxyapatite/Polymer Composite for Bone Tissue Repair Applications: A Review.

Nano-hydroxyapatite (n-HA) is the main inorganic component of natural bone, which has been widely used as a reinforcing filler for polymers in bone materials, and it can promote cell adhesion, proliferation, and differentiation. It can also produce interactions between cells and material surfaces through selective protein adsorption and has therefore always been a research hotspot in orthopedic materials. However, n-HA nano-particles are inherently easy to agglomerate and difficult to disperse evenly in the polymer. In addition, there are differences in trace elements between n-HA nano-particles and biological apatite, so the biological activity needs to be improved, and the slow degradation in vivo, which has seriously hindered the application of n-HA in bone fields, is unacceptable. Therefore, the modification of n-HA has been extensively reported in the literature. This article reviewed the physical modification and various chemical modification methods of n-HA in recent years, as well as their modification effects. In particular, various chemical modification methods and their modification effects were reviewed in detail. Finally, a summary and suggestions for the modification of n-HA were proposed, which would provide significant reference for achieving high-performance n-HA in biomedical applications.

Polyester-enhanced poly (cyclic carbonate-fluoride)-based polymer electrolyte for stable circulating solid lithium batteries

Polymer solid-state electrolytes have become one of the promising materials for constructing solid-state lithium batteries due to their excellent processability and good compatibility with electrode interfaces. However, their limited electrochemical performance and mechanical strength have hindered their widespread application. Through the adoption of an in-situ thermal curing method, we successfully prepared a poly(carbonate-fluoride) solid-state electrolyte, utilizing a polyester separator with abundant polar groups as a reinforcing framework. The introduction of ionic liquid into the solid polymer electrolyte not only enhances the mobility of polymer chain segments to improve ionic conductivity but also, in synergy with trifluoromethyl, promotes lithium salt dissociation while restricting the migration of lithium salt anions. Additionally, their reaction with the lithium metal anode generates the LiF-rich SEI, regulating the deposition of lithium dendrites. The resulting 31VPIF/OZ exhibited outstanding ionic conductivity (3.58 × 10−4 S cm−1 at 25 °C), Li-ion migration number (0.52), and electrochemical window (5.4 V). Li | 31VPIF/OZ | Li battery cycled for 1000 h at 0.1 mA cm−2 without short-circuiting. Importantly, Li | | LiFePO4 battery demonstrated a high capacity retention rate of 91.5 % after 600 cycles at 0.5C (25 °C). Thus, through the synergistic interplay of polymer structure design and fillers, we have successfully achieved stable cycling in solid-state lithium batteries, providing robust support for their application in rechargeable lithium battery technology.

Fabrication, Structural Characterization, and Photon Attenuation Efficiency Investigation of Polymer-Based Composites.

Experiments have assessed various polymer composites for radiation shielding in diverse applications. These composites are lighter and non-toxic when compared to lead (Pb), making them particularly effective in diagnostic imaging for shielding against low-energy photons. This study demonstrates the fabrication of four composites by combining a base material, specifically a high-density polyethylene (HDPE) polymer, with 10% and 20% silicon (Si) and silicon carbide (SiC), respectively. Additionally, 5% molybdenum (Mo) was incorporated into the composites as a heavy metal element. The composites obtained were fabricated into 20 disks with a uniform thickness of 2 mm each. Discs were exposed to radiation from a low-energy X-ray source (32.5-64.5 keV). The chemical and physical properties of composites were assessed. The shielding ability of samples was evaluated by determining the linear and mass attenuation coefficients (μ and μm), radiation protection efficiency (RPE), half-value layer (HVL), and mean free path (MFP). According to our findings, supplementing HDPE with additives improved the attenuation of beams. The μm values showed that composite X-ray shielding characteristics were enhanced with filler concentration for both Si and SiC. Polymer composites with micro-molecule fillers shelter X-rays better than polymers, especially at low energy. The HVL and MFB values of the filler are lower than those of the pure HDPE sample, indicating that less thickness is needed to shield at the appropriate energy. HC-20 blocked 92% of the incident beam at 32.5 keV. This study found that increasing the composite sample thickness or polymer filler percentage could shield against low-energy radiation.

Preparation of cellulose-PCC fibre hybrids: Use as filler in polypropylene (PP) composites

Abstract Polymer composite materials find application in various life sectors such as packaging, lightweight construction and the fabrication of medical devices. Functional fillers like mineral colloids, synthetic and natural fibres enable a precise tailoring of the mechanical properties of the resulting compounds. Precipitated calcium carbonate (CaCO3, PCC) has proven to be a special popular mineral polymer filler. From economic and ecologic reasons, it is desirable to increase filler contents in polymers while maintaining material strength. To achieve this, the present work has developed a hybrid filler system which is based on carboxymethylated, fibrillated cellulose fibres. CaCO3 is precipitated onto the fibres in a single step twin-screw extrusion process by the co-precipitation method. This process ensures a strong, permanent interaction between the fibres and the mineral particles, which enables CaCO3 contents in the filler of up to 68 wt.-%. The resulting hybrid fillers were compounded with polypropylene (PP) in a powder or paste state with filler contents between 5 wt.-% and 20 wt.-%. The resulting composites show an increase in the zero-shear viscosity and, in the event of sufficient network formation, a marked increase in stiffness was observed.

Size Effects of Au/Ni-Coated Polymer Particles on the Electrical Performance of Anisotropic Conductive Adhesive Films under Flexible Mechanical Conditions.

In soft electronics, anisotropic conductive adhesive films (ACFs) are the trending interconnecting approach due to their substantial softness and superior bondability to flexible substrates. However, low bonding pressure (≤1 MPa) and fine-pitch interconnections of ACFs become challenging while being extended in advanced device developments such as wafer-level packaging and three-dimensional multi-layer integrated circuit board assembly. To overcome these difficulties, we studied two types of ACFs with distinct conductive filler sizes (ACF-1: ~20 μm and ACF-2: ~5 μm). We demonstrated a low-pressure thermo-compression bonding technique and investigated the size effect of conductive particles on ACF's mechanical properties in a customized testing device, which consists of flexible printing circuits and Flex on Flex assemblies. A consistency of low interconnection resistance (<1 Ω) after mechanical stress (cycling bending test up to 600 cycles) verifies the assembly's outstanding electrical reliability and mechanical stability and thus validates the great effectiveness of the ACF bonding technique. Additionally, in numerical studies using the finite element method, we developed a generic model to disclose the size effect of Au/Ni-coated polymer fillers in ACF on device reliability under mechanical stress. For the first time, we confirmed that ACFs with smaller filler particles are more prone to coating fracture, leading to deteriorated electrical interconnections, and are more likely to peel off from substrate electrode pads resulting in electrical faults. This study provides guides for ACF design and manufacturing and would facilitate the advancement of soft wearable electronic devices.

Impact of ionic liquids on the thermal properties of polymer composites

Abstract The integration of ionic liquids and polymer composites has become a promising way to improve their thermal properties, representing a notable advancement in the development of advanced materials for specific applications. Their thermal properties heavily influence the suitability of polymer composites for particular applications. It is imperative to understand and manipulate the thermal behavior of these composites to optimize their performance across various fields. In this mini-review, diverse polymer matrices and fillers utilized in polymer composites containing ionic liquids are categorized. Additionally, various ionic liquids employed in studies related to the thermal properties of polymer composites are identified. The impact of ionic liquids on the thermal properties of these composites is also briefly reviewed. The knowledge illustrated in this review enriches the understanding of the types of polymer matrices and fillers used in conjunction with ionic liquids, as well as their thermal properties. In a nutshell, imidazolium-based ionic liquids with tetrafluoroborate, bis(trifluoromethylsulfonyl)imide, hexafluorophosphate, halides, and hydrogen sulfate anions have the impact of improving the glass transition temperature, melting temperature, degradation temperature, and thermal conductivity of thermoplastic, thermosetting, and elastomer composites.

Enhanced Dielectric and Electric Properties of ZnFe2O4‐Poly(Vinylidene Fluoride) Composites by Employing Surface Hydroxylated ZnFe2O4 Nanoparticles

AbstractA facile solvent casting technique has been reported in the fabrication of surface hydroxylated ZnFe2O4 (h‐ZFO) nanoparticles (NPs) filled with poly(vinylidene fluoride) (PVDF) as a matrix. The h‐ZFO filler particles are synthesized from neat ZnFe2O4. The dielectric and electric performance of polymer‐based composites is much related to the interface binding between filler particles and polymer matrix. In this work, the surface alternation technique employed a new path is developed to improve the compatibility between ZFO particles and the PVDF matrix. These PVDF‐ZFO composites were studied by X‐ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The h‐ZFO‐PVDF and ZFO‐PVDF composites are carefully analyzed by dielectric and electric properties by a wide range of frequencies. However, the morphological analysis exhibits uniform dispersion of the h‐ZFO NPs in the PVDF matrix. The h‐ZFO‐PVDF composites have a dielectric constant of about 35 for 1.5 wt.% of filler contents. Moreover, the h‐ZFO‐PVDF composites have lower dielectric loss than PVDF‐ZFO composites. It is suggested that the strong interaction between h‐ZFO filler particles and the PVDF matrix is the main reason for the improvement of dielectric properties. The outcomes of these methods have great potential for making high dielectric constants and relatively suppressed loss PVDF‐ZFO composites for advanced practical applications.

Influence of the number of end-chain amine-functionalized arms of star-shaped functionalized SBR

Star-shaped SBRs with alkoxy silyl groups in the center of the molecule and amine groups at the polymer chain ends were prepared. The number of arms were varied, and its influence on the silica/silane-filled compound properties was investigated. The polymer–filler interactions and the filler–filler interactions were evaluated from the viscoelastic properties. The flocculation, tensile properties and tanδ at 60 °C, an indicator of rolling resistance, were investigated as well. The polymer–filler interactions were increased in the SBR with a higher number of arms due to the higher amount of amine groups in these SBRs. The Payne effect was slightly increased with a higher number of arms. This indicates a deteriorated micro-dispersion of the silica caused by too many interactions generated by the higher amount of amine groups in SBR. These high interactions due to the amine groups lead to higher tensile moduli. The combination of the higher polymer–filler interactions and the higher Payne effect in SBR with a high number of arms results in the same tanδ compared to the SBR with a low number of arms.

High energy storage performance in poly(vinylidene fluoride)-based all-organic composites via optimizing the structure of semiconductive filler

The great demand for miniaturization and lightweight energy equipment stimulates the fast development of polymer-based dielectrics with low density and easy processability. Unfortunately, the low energy density puts barriers to the development of polymer dielectrics in the new energy industry. In this work, poly(vinylidene fluoride) (PVDF)-based blending films are prepared and the energy storage properties are explored by regulating the content and structure of semiconductive polymer fillers. The experiment results show that when poly{2-((3,6,7,10,11-pentakis(hexyloxy)triphenylene-2-yl)oxy)ethyl methacrylate} (P6) filler is added, 0.25 wt%-P6/PVDF film attains the maximal discharge energy density (Ud) of 19.1 J cm−3 at 624 MV m−1. Compared with poly{2-((3,6,7,10,11-pentabutoxytriphenylen-2-yl)oxy)ethyl methacrylate} (P4) filler, the P6 filler possesses better compatibility with PVDF and creates deeper traps to suppress the carrier migration and achieve the higher breakdown strength. This research offers useful references for the design of polymer-based composites with excellent energy density through blending triphenylene semiconductive fillers.

Electric conductive fibers from extrinsic conductive fillers with thermoplastics by melt spinning

Abstract The aim of this review is to identify the literature for the scientific work to understand the basics of the conduction mechanism of electrically conductive filament yarns made from extrinsic con-ductive fillers and thermoplastic polymer using melt spinning. In recent years, extrinsic conductive fillers have become very popular due to their electrical conductivity and have received greater research attention. In general, extrinsic conductive fillers are carbon-based conductive materials. These include carbon black (CB), carbon nanotubes (CNT), graphene and graphite. This thematic review mainly focuses on the thermal, mechanical and electrical properties of melt-spun thermoplastic polymers, such as polypropylene, polyamide, poly(ethylene terephthalate), thermoplastic polyurethane, polycarbonate, polyimide, poly(methyl methacrylate and poly(L-lactide)) acid with CB, CNT, graphene and graphite. The structure, shape, size and properties of extrinsic conductive fillers are described in this review. The development of electrically conductive filament yarns from extrinsic conductive fillers using the melt spinning process requires a consideration of the entire process, from pre-treatment, compounding and melt spinning of the extrinsic conductive fillers to the drawing of the electrically conductive filament yarn. In order to achieve better spinnability of the two different components (conductive filler, thermoplastic polymer), an overview of the pretreatment methods of the extrinsic conductive filler and thermoplastic polymers is given. Mixing of inorganic nanomaterials into a polymer matrix involves many challenges, like agglomeration, poor dispersion and scattering of the extrinsic conductive filler within the thermoplastic polymer. Therefore, the most important influencing factors of the melt spinning process are discussed in detail in this review. Depending on the type of polymer (amorphous, crystalline, semi-crystalline), extrinsically conductive fillers can influence the crystallization process in different ways. The textile mechanical and electrical properties of the spun extrinsically conductive yarn will be comprehensively highlighted. Finally, new developments in the field of conductive filament yarns are presented

Development of Green Composites Based on Castor Bean Shell (Ricinus communis) as Filler in Epoxy Resin Polymer

Development of Green Composites Based on Castor Bean Shell (Ricinus communis) as Filler in Epoxy Resin Polymer

Synthesis and assessment of novel Na2S dispersed high performance nanocomposite gel polymer electrolyte intended for sodium batteries and electric double layer capacitors

Sodium sulphide (Na2S) nanoparticles are synthesized by hydrothermal method and utilized for electrochemical application for the first time. A series of sodium-ion conducting nanocomposite gel polymer electrolytes (NCGPEs) incorporating poly (methyl methacrylate) i.e., (PMMA) as the polymer backbone, sodium tetrafluoro-borate (NaBF4) as the salt, tetraethylene glycol dimethyl ether (TEGDME) as the plasticizer, and Na2S as the active fillers, are fabricated and studied. The optimized electrolyte having PMMA/NaBF4/TEGDME matrix incorporated with 2.5 wt% Na2S nanoparticles exhibits a high ionic conductivity of 3.0 × 10−4 S cm−1, low activation energy of 0.13 eV and operating voltage range of ~2.8 V at ambient temperature. Thermal studies reveal that the fabricated NCGPEs have the ability to retain the gel phase up to 473 K. The X-ray diffraction (XRD) and Fourier transform Infra-red (FTIR) spectroscopy indicate changes in structure and the ion–filler–polymer interactions inside the synthesized NCGPEs. A proto-type sodium cell with an optimized NCGPE has an open circuit voltage of 2.3 V and a first discharge capacity of 205 mAh g−1. The electric double layer capacitor (EDLC) designed with optimized electrolyte has a specific capacitance of 58 F g−1 and is stable up to 2000 charge-discharge cycles.

Influence of hybrid filler on charge conduction and storage performance of polyvinyl chloride/nitrocellulose blend for hybrid electrolyte application

AbstractPolymer blends of polyvinyl chloride/nitrocellulose/MoS2‐Nafion (PVC/NC/MoS2‐Nafion) were prepared using a casting technique. FTIR analysis revealed chemical interactions between the polymer matrix and filler. XRD analysis was employed to investigate changes in structural phases, while SEM illustrated the agglomerated morphology of the modified blends. The critical role of ionic interaction between Nafion and polymer system in enhancing electrical properties was confirmed through impedance analysis. The introduction of oxygenated functionalities improved surface topography and roughness, as observed by AFM. Electrical conductivity increased from 10−6 S/cm to 10−4 S/cm, accompanied by a decrease in activation energy (Ea). The addition of Nafion decreased bulk resistance, indicating enhanced ionic mobility, as supported by impedance analysis. TG‐DSC analysis demonstrated that MoS2 and Nafion improved thermal properties of polymer blends. The glass transition temperature (Tg) increased by approximately 13 °C and 21 °C with MoS2 and Nafion, respectively. Universal testing machine (UTM) results indicated moderate tensile strength and Young's modulus achieved by MoS2 and Nafion. With increasing Nafion loading, elongation at break rose to around 71 %, showcasing excellent interfacial interaction in polymer‐filler system. The resulting polymer blends, modified by Nafion, exhibited high ionic/electrical conductivity and show promise for hybrid polymer electrolyte applications.

Structure and properties of wet-spun nylon/graphene nanocomposite fibers

Due to an increasing demand for more portable and intelligent electronic devices, strong and flexible fibers which are also electrically conductive and thermally stable are currently on demand. Herein, wet-spun nylon/graphene nanoplatelets (GNPs) and nylon/reduced graphene oxide (rGO) nanocomposite fibers were fabricated in a range of filler loadings and the effect of the type of graphene employed and the presence/absence of ions absorbed into the fibers during coagulation on their structure, processing and properties was evaluated. The diameters were homogenous along the fibers and similar for identical loadings of both fillers. The increasing viscosities of the dopes with increasing filler loadings were, however, reducing progressively the processability of the systems, leading to increasingly thicker and more defective fibers. The nanocomposite fibers behaved as electrically percolated systems, with considerably lower percolation threshold found for the rGO based fibers relative to the GNPs based ones due to the higher aspect ratio of rGO relative to GNPs. The richer surface chemistry of the rGO flakes provided stronger filler–polymer interfaces, leading to a higher optimal loading and effective modulus relative to the GNPs system. Whereas the presence of ions from the coagulation bath did not affect the diameters, microstructure or electrical properties of the fibers, it was found to have an impact on their mechanical properties, thermal stability and melting and crystallization behavior. This knowledge is key to gain control on the design of nanostructured fibers with specific structure and properties that meet the requirements for particular applications in the field of multifunctional textiles.