Dispersion Of Filler Particles Research Articles

Механические свойства композиции на основе полиэфирной смолы с частицами оксида меди (I)

The mechanical properties of polyester resin composition with copper (I) oxide dispersed filler particles (non capsulated, capsulated by polylactide, and dissolved by the resin components) are considered in that paper. It was showing that a capsulated filler particle has better interaction with polymer matrix than non capsulated particles. So, the tensile strength and hardness of PCM are increasing, but ultimate deformation is decreasing. The strength characteristics of PCM with partial dissolution of copper (I) oxide particles by the components of the polyester resin was decrease. The density of the polymer binder network due to the loss of styrene, as well as the formation of complexes of copper salts are the cause of strength characteristics decrease.

Development of flexible PVDF/ BaTiO3-MoS2 polymer nanocomposites for energy harvesting and gas sensing applications

The need for flexible and wearable devices is quite great in the modern era of advanced electronics and the Internet of Things (IoT). Here, we present a poly(vinylidene fluoride) (PVDF)/Barium Titanate–Molybdenum Disulfide (BaTiO3–MoS2) composite-based flexible piezoelectric nanogenerator (PENG) with an improved electroactive phase. The electroactive, β-phase of the PVDF is shown to increase with the addition of BaTiO3–MoS2 fillers as a result of the filler’s good interfacial interaction with the polymer matrix. The improved electroactive phase in the PVDF matrix was confirmed by the X-ray diffraction method and FTIR analysis of the composite films. The uniform dispersion of filler particles in the polymer matrix was confirmed by a scanning electron microscopy analysis. The developed piezoelectric nanogenerator device generated peak-to-peak output voltage of 4.9 V with a high dielectric constant of 22 and a low dielectric loss of 4.7. The fabricated gas sensor can perform at room temperature and exhibits good gas sensing performance toward the NH3 gas. It was found that, compared to all other samples, the composite PVDF/BaTiO3–MoS2 films had a high level of sensitivity. Additionally, the composite films showed response and recovery times of 11 and 17 s. The composite based on PVDF/BaTiO3–MoS2 is a suitable material for NH3 sensor applications.

Initial Study on Rheological Behaviour of Hydroxyapatites / Polylactic Acid Composite for 3D Printing Filament

The present fused deposition modeling (FDM) printing process has concentrated on combining metal or ceramic filled with polymer because it could provide a strong composite in layered manufacturing technology in comparison to a single polymer material. However, the ability of the composite material to flow into the extruder becomes an obstacle because of the changes in the polymer concentration and dispersion of filler particles in producing the printed part. Hence, the rheological behavior of Hydroxyapatites (HAp) / Polylactic Acid (PLA) composite with different contents of HAp was studied to assess its ability to flow through the extruder during the 3D printing process. Measurements such as pycnometer density, thermal analysis (DSC) and FT-IR were performed on the composite feedstock containing a variation of 10% to 30% HAp powder. The feedstocks behavior then were characterized by rheological tests at three different temperatures (140 oC, 150 oC, and 160 oC). The composition of PLA/20HAp has produced optimum rheological behavior with effective flow behavior index (n) and activation energy (E) of 0.396 and 89.03 kJ/mol, respectively which is suitable for extruding out the HAp/PLA composite to become a 3D printing filament material.

The effect of alkali treatment on the mechanical properties of date seed particulates waste polypropylene filled composites

Date seeds collected as waste were reduced to 63 µm particles and treated with NaOH (aq) at 1, 3, 5, 7 and 10 %. The extent of chemical modification was assessed using FTIR analysis. The waste polypropylene (wPP)/date seed particles (DSP) composites filled with untreated and treated particles at 20 % filler loadings were fabricated using compounding and compression moulding techniques by means of two rolls mill. Tensile, flexural, impact tests and hardness (HV) were conducted and evaluated. Subsequently, a morphological study of the fractured surface of the composites was achieved using SEM. The application of alkali treatment enhanced various properties of the composites at the optimal concentration of 10 % w/v. Specifically, the tensile strength, flexural strength, elongation at break, impact strength, and hardness were improved, resulting in values of 28.86 MPa, 140 MPa, 172.5 %, 0.92 J/m², and 23.8 Hv, respectively. While tensile and flexural moduli showed a decrease with increasing alkali concentration. The SEM of the fractured surface of the treated composite revealed a better dispersion of filler particles within the matrix with no cluster seen compared to the untreated.

Transport properties of radiation vulcanized natural rubber latex nanocomposites

Radiation vulcanized natural rubber latex (RVNRL) nanocomposites were prepared by the incorporation of aqueous dispersions of nanosilica and nanoclay in RVNRL latex. The sorption, diffusion, and permeation coefficients of the composites were measured at 303 K. The magnitude of the diffusion coefficient showed a decreasing trend in RVNRL/nanosilica composites followed by nanoclay and china clay composites. The diffusion of solvent through rubber followed a first-order kinetics. The transport phenomenon was found to follow an anomalous behaviour. XRD analysis showed that nano silica particles were homogeneously distributed in the rubber matrix. The particle size of the nano silica is 10 nm as confirmed from TEM analysis. RVNRL/nano silica composites showed better dispersion of filler particles in natural rubber.

Effect of combined micro and nano silicon carbide particles addition on mechanical, wear and moisture absorption features of basalt bidirectional mat/vinyl ester composites

AbstractBasalt fiber reinforcement in polymer composites has recently become very competitive to the routinely used synthetic fiber reinforcements. In the present work, composite specimens were prepared with basalt fiber mat reinforcement in vinyl ester matrix along with varying quantity of the micro and nano silicon carbide (SiC) filler particle ranging from 1 to 5 wt% in combination. Tribological and water absorption properties of the developed hybrid composites were tested to ascertain its potential for commercial applications. The specimen made of SiC particle addictive combination of 3 wt% nano and 3 wt% micro particle exhibited better mechanical characteristics and this mechanical advantage declines beyond 3 wt% SiC filler addition due to agglomeration and poor dispersion of filler particles in the hybrid composite. The microstructural investigation done via scanning electron microscopy reveals the modes of failure, where better pull‐out resistance was displayed by the fiber bonding characteristics with the filler and vinyl ester matrix up to 3 wt% nano and 3 wt% micro SiC filler content. Similarly, the tribological characteristics of the composite specimen for the optimum filler content specimen were superior in comparison with other combinations. Moreover, the water absorption features of the developed hybrid composites were within the acceptable limits for marine and structural applications.

Uticaj nanopunila i masterbača na svojstva silokasnih materijala

Nanocomposites based on siloxane and silicon(IV)oxide nanoparticles (with a hydrophilic and hydrophobic surface) were synthesized to design the desired final properties of the composite material. Masterbatch, a mixture of siloxane containing vinyl functional groups and reinforcing fillers, was added to improve the mechanical properties and topology of siloxane networks. Silicon(IV)oxide was added in amounts of 1, 5, 10, and 20 wt% and masterbatch in amounts of 5 and 10 wt% to examine the effect of the amounts of fillers and masterbatch in the synthesized samples. Fourier transform infrared spectroscopy was used to analyze the chemical structure of the obtained materials. Transmission electron microscopy (TEM) was used to examine the dispersion of filler particles in siloxane nanocomposites. To examine the thermal stability and phase transition temperature of siloxane materials, thermogravimetric analyzes (TGA) and differential scanning calorimetry (DSC) were performed. The addition of masterbatch did not lead to a significant difference in melting temperature, but stoichiometry was disturbed, which decreased the thermal stability compared to samples without masterbatch. The addition of masterbatch to nanocomposites with hydrophilic fillers increases both elongations at break and tensile strength. According to the results, the combination of masterbatch and nanofillers affects the properties of siloxane materials, which could enable obtaining materials with the desired properties.

Investigation of the properties of composite materials based on epoxy resins with microsilica additives

The outcomes of studying epoxy-based composite materials supplemented with microsilica are provided in the article. Microsilica was used as a filler. The samples were produced on the epoxy ED-20 basis supplemented with 2, 5 and 10 mas. % of microsilica. The structure and size of finely dispersed filler particles were defined. The obtained composites were tested for resistance to the effect of variable temperatures, corrosive, and abrasion. The study outcomes proved that samples supplemented with 2% of microsilica are more resistant to acid and alkali as well as to petrol than those ones supplemented with 25% of microsilica. Besides the amount of the filler from 2 to 10% doesn’t sufficiently affect the resistance to variable temperatures. When microsilica is added to epoxy resin, it causes scuff resistance increase. The conducted testing proved that the developed composite materials are resistant to the effect of variable temperatures, corrosive, and abrasion. This enables to use these materials as coatings and anti-corrosion protection during machine maintenance.

Electron-paramagnetic resonance and infrared spectroscopic research of the structure of a southfield Polyvinylidene difluoride near the percolation threshold

In this paper, the results of scientific research work are carried out to study the role of the interfacial layer in filled polymer materials using infrared and electron-paramagnetic resonance spectroscopy using the fundamentals of solid-state physics. At the same time, the authors of this work used all the rich experience of both experimenters and theoreticians working in this field of science and their own developments regarding methods for controlling the structure of these materials. It is noteworthy that the material interpreted in this work concerns composites subjected to special technological preparation, including the stage of ultrasonic dispersion of filler particles in a binder medium.

Incorporation of Recycled Polypropylene and Fly Ash in Polypropylene-Based Composites for Automotive Applications

The principal aim of this study is to investigate the utilization feasibility of waste materials, i.e., recycled Polypropylene (PP), and fly ash in the formulation of auto parts which are commonly designed based on PP. The typical formulation of auto parts consists of PP, elastomer, filler, and compatibilizer. Various recycled PP/virgin PP ratios were considered as the matrix of the composites. It is found that the increasing concentration of recycled PP in the composite leads to a reduction in mechanical properties, particularly ductility and impact strength. However, due to a lower viscosity at the presence of recycled PP, better dispersion of filler particles, observed by SEM analysis, leading to the improvement of tensile strength. Besides, the employment of recycled material lowers the percentage of crystallinity and melting temperature. It is deduced that the deployment of 20/80 to 40/60 ratios of recycled PP/virgin PP in the composites reasonably meets the requirements for auto parts with advantages in the environmental and economic aspects. Compared to the composites filled with talc, the ductility of fly ash-filled composites is higher. The simultaneous utilization of talc and fly ash as a hybrid system brings about higher ductility, but lowers impact strength compared to talc-filled samples. Using recycled PP mixed with fly ash provides advantages in cost reduction and sustainable and environment-friendly production.

Stochastic Finite Element Analysis Framework for Modelling Electrical Properties of Particle-Modified Polymer Composites.

Properties such as low specific gravity and cost make polymers attractive for many engineering applications, yet their mechanical, thermal, and electrical properties are typically inferior compared to other engineering materials. Material designers have been seeking to improve polymer properties, which may be achieved by adding suitable particulate fillers. However, the design process is challenging due to countless permutations of available filler materials, different morphologies, filler loadings and fabrication routes. Designing materials solely through experimentation is ineffective given the considerable time and cost associated with such campaigns. Analytical models, on the other hand, typically lack detail, accuracy and versatility. Increasingly powerful numerical techniques are a promising route to alleviate these shortcomings. A stochastic finite element analysis method for predicting the properties of filler-modified polymers is herein presented with a focus on electrical properties, i.e., conductivity, percolation, and piezoresistivity behavior of composites with randomly distributed and dispersed filler particles. The effect of temperature was also explored. While the modeling framework enables prediction of the properties for a variety of filler morphologies, the present study considers spherical particles for the case of nano-silver modified epoxy polymer. Predicted properties were contrasted with data available in the technical literature to demonstrate the viability of the developed modeling approach.

Fluorescent labeling and image analysis of cellulosic fillers in biocomposites: Effect of added compatibilizer and correlation with physical properties

The performance of cellulosic filler/polyolefin biocomposites is affected by the filler dispersion (aggregation and spatial arrangement) in the matrix. However, this mechanistic factor is generally inferred from the physical properties of the final bulk material because of the limitations of analytical techniques. Herein, we propose a simple method to quantitatively evaluate the dispersion of filler particles. To accomplish this, the cellulose component in injection-molded specimens of microcrystalline cellulose (MCC)/maleic anhydride-modified polypropylene (MAPP)/polypropylene (PP) composites was selectively fluorescently labeled with calcofluor white, and the dispersion state of tens of thousands of MCC particles observed by fluorescence microscopy was analyzed. The close-range aggregation behavior of the MCC particles can be evaluated by the area of the fluorescent particles (A), and the normality (randomness) of the spatial arrangement can be classified by the skewness of the distribution of the distances between the centroids of the particles (s). As a result, with an increase in the degree of acid modification of the added MAPP, aggregation of MCC was suppressed and the spatial arrangement became random. Both A and s were not associated with the modulus or fracture strain of the injection-molded specimens, but they were correlated with the tensile and bending strengths and water absorption behavior. This visualization method was also applied to a composite containing nanofibrillated cellulose filler (citric acid-modified cellulose nanofiber).

Deformability in Unsaturated Polyester Resin-Based Concrete: Effects of the Concentration of Shrinkage-Reducing Agent and Type of Filler.

In this study, the effects of shrinkage reduction agent (SRA) content and filler type on the deformability characteristics of unsaturated polyester (UP) resin-based polymer concrete were experimentally investigated. Specifically, the setting shrinkage, thermal expansion, maximum compressive strain and the modulus of elasticity of UP polymer concrete were all analyzed. Setting shrinkage was found to be influenced by the UP resin, the SRA and filler. The thermal expansion, maximum compressive strain and modulus of elasticity were also affected by the aggregate. The effect of SRA content on deformability was found to be greater than that of the filler type. To put UP polymer concrete to efficient use, it is essential to secure proper deformability according to the intended purpose. At that time, it is desirable that the deformation characteristics resulting from the SRA content and filler type sufficiently reflect when the mix proportion is determined. The effects of filler type on the deformability of UP polymer concrete are such that: A uniform dispersion of filler particles impacts the setting shrinkage; the thermal expansion is influenced by the filler’s various thermal expansion properties; the compressive strain is related to the nature of the small spherical particles that tend to fill porosity, producing better packing of the aggregate materials; and the modulus of elasticity is influenced by the density, which is related to the strength of the filler. However, additional in-depth studies are required on all of these elements.

Effects of Filler Type in Bismaleimide Matrix on Corrosion Resistance of Steel in Sea Salt

Bismaleimide (BMI) coating with and without aluminum oxide (Al2O3), silica oxide (SiO2), hexagonal boron nitride (h-BN), or organophilic montmorillonite clay 30B (OMMT) fillers on 1018 steel substrates was studied. Bilayer coatings consisting of BMI with one of the fillers at 5 wt.% for the first layer and pure BMI for the second layer were applied on 1018 steel substrates. The corrosion resistance of all coated samples was investigated through potentiodynamic polarization by using Tafel method in 4.2 wt.% sea salt solution. The results of the test showed that pure BMI coating improved the corrosion resistance by reducing the corrosion rate by 88%. Addition of 5 wt.% of OMMT or SiO2 fillers increased the efficiency of the coating in reducing corrosion rate by 99 and 97%, respectively. Adding 5 wt.% h-BN showed marginal improvements in the reduction in corrosion rates (89%). Addition of 5 wt.% Al2O3 as a filler dropped the efficiency of BMI coating to 64%. Adhesion of the coated steel was also affected depending on the filler type. Micro-hardness measurements using Vickers scale were taken to assess coating hardness, and scanning electron microscopy was used to investigate the dispersion of filler particles in the matrix.

Mixing time influence on fatigue crack growth in a carbon black-filled natural rubber vulcanizate

Various processing parameters affect the dispersion of carbon black (CB) in a rubber matrix, of which mixing time plays a major role. The physical properties of a green compound namely bound rubber and Mooney viscosity along with mechanical and fatigue crack growth (FCG) are affected by the dispersion of filler particles. To determine the effect of mastication on dispersion, the mixing time was varied from 120 s to 600 s where it was gauged that an optimum range of mixing times display better dispersion. The difference in dispersion between the green and the cured compounds was also stark due to the flocculation mechanism. Longer mixing times do not show much decrease in agglomerate size on curing, that is, approximately 2%, whereas shorter time has led to a decrease of 20%. The FCG properties were studied using a tear and fatigue analyser, where the FCG rate displays a similar trend with the dispersion of CB.

3D aerosol printing as method to obtain low-temperature ceramic layers of printed circuit boards

A method for the synthesis of the polyaluminosilicates (PAS) with the macromolecules of dendrimer morphology has been developed. A quantum-chemical assessment of thermodynamically possible mechanisms to develop the populations of short-chain aluminosilicates (nuclei of dendrimer macromolecules) has been carried out followed by the domains generation from the dendrimer assemblies capable to contain up to 80 % wt of the dispersed filler particles into their interdomain spaces by means of the GAUSSIAN B3LYP/6-31G (d) software package. A quantitative calculation of the parameters determining the composition of PAS macromolecules and the size of the dendrimer assemblies has been carried out. A method for the synthesis of monomeric precursor-powder has been developed. A new low-temperature ceramic composite material for 3D aerosol printing has been developed on the basis of the PAS and highly dispersed precursor-powder. The processes of 3D aerosol printing of the PAS filled with monomeric precursor-powder have been researched. An optimal method for aerosol generation has been chosen that does not affect the PAS supramolecular structure. The ceramic dielectric layers with high consumer properties have been obtained by means of 3D aerosol printing.

Styrene butadiene rubber/epoxidized natural rubber/carbon filler nanocomposites: microstructural development and cure characterization

Microstructural development of elastomeric nanocomposites based on (50/50 wt%) styrene butadiene rubber (SBR) and epoxidized natural rubber (50 mol% epoxidation, ENR50) as the rubber matrix including two types of carbon fillers, carbon black (CB) and functionalized multiwall carbon nanotube (NH2-MWCNT), which were prepared through melt mixing, was studied. The results from FTIR analysis show that there is interaction between functional groups on MWCNT surface and the rubber chains. The AFM analysis also indicates good dispersion of filler particles in the rubber phases. FESEM images from cryo-fractured surface of samples have revealed that nanotubes were rarely pulled out of matrix and their diameter increased, resulting from good interaction between MWCNTs and rubber chains. The DMA results confirm good interfacial interaction between them. Furthermore, the reduced difference between the two Tgs of phases (ΔTg) shows that the incorporation of 3 phr MWCNT into the blend leads to increment in rubber phase compatibility but at higher MWCNT content (5 phr) due to lower Mooney viscosity of SBR phase, MWCNTs tend to remain in this phase. The bound rubber was adopted to characterize the polymer–filler interaction, showing that bound rubber content has an increasing trend with increasing in fillers content. The cure rheometric studies reveal that MWCNTs accelerate the cure process due to the presence of amine groups on the nanotube surface. In addition, the mechanical properties of samples show an increasing trend by increasing nano-filler content.

Study of interfaces in polymer-metal oxide films and free-volume hole using low-energy positron lifetime measurements

Abstract To reveal how the distribution of different nano fillers affect the UV-shielding efficiency of their polymer-based composites and to further develop a simple strategy to refrain the erection of the composites, we prepared ZnO doped polystyrene (PS/ZnO) and TiO2 doped polystyrene (PS/TiO2) films by the solution cast technique with different concentrations of ZnO and TiO2 (0.25%, 0.5%, 0.75% and 1%.). Contrary to the common observation, the better tunability for UV shielding efficiency was found in the case of TiO2 as compared to ZnO. This is mainly due to the appearance of a rod like structure on neat PS which has improved the dispersion as well as provides a higher interface area that enhanced the UV-absorption efficiency of the PS matrix. This analysis is equally supported by the PALS study where the free volume was closely associated with the interfacial interaction between the filler and the PS matrix. These observations recommend that the better dispersion of filler particles leads a stronger interfacial interaction and enhances the UV-protection efficiency of the composite materials.

Piezoelectric Films Based on Polyethylene Modified by Aluminosilicate Filler.

The development, universality and miniaturization of electronic devices leads to the search for new piezoelectric materials, among which recently, polymers play an increasingly important role. In this work, composites based on two types of polyethylene—high density polyethylene (HDPE), and medium density polyethylene (MDPE)—and aluminosilicate fillers were obtained by extrusion process. This method allowed obtaining flexible electrets in the form of a thin film after polarization under a constant electric field of 100 V/μm. The morphology of the composites was characterized by scanning electron microscopy, whereas the crystallinity was determined by X-ray diffraction. The mechanical properties and thermal stability of the composites were examined by means of tensile tests and thermogravimetry, respectively. The piezoelectric characteristics were appointed by measuring the electric charge and the voltage in the polarized samples. Piezoelectric coefficients, and the stability of electrets over time were also determined. Moreover, the effect of film orientation on piezoelectric properties was investigated. Composites with appropriate morphology (i.e., well dispersed filler particles in the polymer matrix and formed holes) were obtained which ensured permanent electrical polarization. It was found that the best piezoelectric, mechanical properties and thermal stability exhibits HDPE composite with 5% of aluminosilicate filler.

Preparation of rubber seed shell powder by planetary ball milling and its influence on the properties of starch foam

Starch foam composites containing rubber seed shell particles of different sizes were prepared and characterized. The first objective was to prepare small particles of rubber seed shell using a planetary ball mill at different rotational speeds (300 and 600 rpm) and milling times (20, 40 and 60 min) to optimize the milling condition to achieve the smallest possible particle size. The second objective was to study the influence of the size of the rubber seed shell particles on the properties of the starch foam. Laser particle size analysis and morphological observation by scanning electron microscope (SEM) revealed the optimal milling condition to be 600 rpm for 40 min. The smallest average particle size obtained at this condition was 51.57 μm. Starch foam containing the smallest particles (GRS) exhibited greater flexural stress at maximum load and narrower cell size distribution and had a lower density than starch foam composite with crude rubber seed shell (CRS) at the same filler content. The small size and high surface area of GRS enabled a better dispersion of filler particles and the establishment of stronger interactions within the starch matrix. The change in the color parameters and whiteness values of the rubber seed shell particles can be attributed to exposure to the heat generated by ball milling and the reduction of the average particle size. The effect of the addition of GRS and CRS on the thermal properties of the composites was determined by simultaneous thermogravimetry – differential scanning calorimetry.