Inactive Filler Research Articles

The Viscoelastic Behavior of Legume Protein Emulsion Gels—The Effect of Heating Temperature and Oil Content on Viscoelasticity, the Degree of Networking, and the Microstructure

Legume proteins are increasingly used in structuring various foods under the influence of heating and stirring energy. Based on available studies, this structuring potential is not yet fully understood. This raises the question of the suitability of legume isolates and concentrates for structuring in emulsion gels and the effect of heat and oil on the gel properties. In this study, soy- and pea-based suspensions and emulsions were prepared with the least gelling concentration using different oil concentrations (0%, 7.5%, 15%, 22.5%, and 30%). The viscoelastic properties were measured before and after heating cycles (65 °C and 95 °C). Scanning electron microscopy images complemented the results. All gels measured showed viscoelastic solid behavior. Thermal treatment showed a positive effect on the gel properties for most samples, especially for concentrates (reduction in the loss factor and networking factor > 1). The concentrates showed much higher networking factors and tighter cross-linking than the isolates. The rheological and microstructural properties of the emulsion gels are influenced by a number of factors, such as carbohydrate content, protein chemistry, the protein purification method, and initial viscosity. Moreover, the influence of oil on the rheological properties depends on the material used and whether oil droplets act as an active or inactive filler.

Cellulose reinforcement of plant-based protein hydrogels: Effects of cellulose nanofibers and nanocrystals on physicochemical properties

This study explored the impact of cellulose-derived fillers, cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs), on the microstructure and texture of potato protein hydrogels (20 wt% protein). Particle size analysis, surface charge analysis, and molecular docking simulations suggested that the cellulose nanofibers and nanocrystals acted as inactive fillers within the potato protein matrix. Texture profile analysis showed that incorporation of small amounts of CNFs (<1%) increased the gel strength (by up to 69%), but the addition of larger amounts decreased it, which was attributed to disruption of the protein network by aggregated nanofibers at higher concentrations. The incorporation of CNCs had a much smaller effect on the gel strength of the potato protein hydrogels, only increasing it by up to 15% at 2% CNC. Shearing the cellulose-reinforced hydrogels in a shear rheometer had little impact on their gel strength at lower filler concentrations (<2 wt%) but increased it at higher concentrations. Microscopy analysis showed that the cellulose fibers could be aligned at sufficiently high shearing rates, leading to a fibrous microstructure. This study provides valuable insights into the optimization of the properties of cellulose fillers for application in plant protein hydrogels. In particular, it suggests that they may be utilized in plant-based meat analogs to enhance their textural attributes and optimize their appearance.

Impact of Oil Bodies on Structure, Rheology and Function of Acid-Mediated Soy Protein Isolate Gels.

Oil bodies (OBs) are naturally occurring pre-emulsified oil droplets that have broad application prospects in emulsions and gels. The main purpose of this research was to examine the impact of the OB content on the structure and functional aspects of acid-mediated soy protein isolate (SPI) gel filled with OBs. The results indicated that the peanut oil body (POBs) content significantly affected the water holding capacity of the gel. The rheological and textural analyses showed that POBs reduced the gel strength and hardness. The scanning electron and confocal laser scanning microscopy analyses revealed that POBs aggregated during gel formation and reduced the gel network density. The Fourier transform infrared spectrum (FTIR) analysis demonstrated that POBs participated in protein gels through hydrogen bonds, steric hindrance and hydrophobic interactions. Therefore, OBs served as inactive filler in the acid-mediated protein gel, replaced traditional oils and provided alternative ingredients for the development of new emulsion-filled gels.

Two in one: The use of hexagonal copper sulfide (CuS) nanoparticles as a bifunctional high-performance cathode and as a reinforced electrolyte additive for an all-solid-state lithium battery

All Solid-State Batteries (ASSBs) based on solid polymer electrolytes (SPEs) have improved safety, energy, and power densities than conventional liquid electrolyte-based Lithium-ion batteries (LIBs). However, two significant obstacles still need to be addressed, including the low ionic conductivities and the low interfacial contact between ASSB components. This study involves the fabrication of hexagonal CuS nanoparticles by a one-step hydrothermal method and uses them for both cathode and solid electrolyte formulation functions. The reasonable ionic conductivity of 4.68 × 10−4 S.cm−1 at 60℃ and the instant transport number of 0.86 of the designed CuS filler-incorporated solid electrolyte offered great promise for ASSBs applications. In particular, the CuS filler-incorporated solid electrolyte exhibited ceaseless and prompt Li-ion transportation kinetics and delivered a dendrite resistance capability over 200 cycles of stripping/plating of Li. In addition, the Li metal solid-state battery is also verified using CuS as the cathode and SPE electrolyte (PEO/LiTFSI/CuS SPE) system. It offers an initial discharge capacity of up to 695 mAh/g and keeps an average capacity of ∼ 365 mAh/g after 50 cycles at a current density of 0.5C. Thus, this study introduced a simple but effective solution to mitigate the dendrite problems associated with solid polymer electrolytes by using CuS as a durable inactive filler.

Preparation and evaluation of goat cream cheese analogue for phenylketonuria

The primary treatment for individuals with phenylketonuria (PKU) is a lifetime diet with low phenylalanine (Phe) to achieve neurological health. The objective of this study was to make a highly nutritious and palatable low‐Phe cream cheese analogue based on the partial replacement of fresh goat cream cheese with two levels of glycomacropeptide (GMP; 7 or 10%), GUM (0.6 or 0.8), nondairy creamer (0.5 or 2%) and whey protein concentrate (WPC; 0 or 2%). The chemical composition, texture, viscosity, protein digestibility and sensory attributes of the resulting cheeses were evaluated. Incorporation of the GMP at different levels significantly changed the chemical properties of the cheese. With increased levels of GMP and GUM, viscosity and firmness significantly increased as the protein–protein and protein–gum interaction produced stronger gels in comparison with the systems containing nondairy creamer and WPC due to their inactive filler, whereas adhesiveness decreased. Sensory characteristics of cheese indicated that formula made with high concentration of variables seems to be superior for PKU patients, which contained 12.44 mg Phe per gram of protein, and 82.4% protein digestibility after 6 h of enzymatic hydrolysis. According to the results, the method used in this study can be employed in achieving cream cheese analogue with reduced Phe content, appropriate for PKU patients.

Electromagnetic absorption shielding effectiveness and physical‐mechanical properties of rubber composites

AbstractManganese‐zinc ferrite, nickel‐zinc ferrite, and the combinations of both ferrites in constant level 200 phr were incorporated into acrylonitrile‐butadiene rubber. The amount of carbon black was constant in each composite −25 phr. The second series of composites was fabricated with similar composition, but the total content of ferrites or ferrites combinations was 300 phr, while the content of carbon black was 25 phr. The work was focused on investigation of electromagnetic absorption shielding effectiveness of composites and their physical‐mechanical properties. During the study, good correlation between conductivity, permittivity, and electromagnetic absorption parameters was established. Higher conductivity was reflected in higher permittivity of composites, which subsequently resulted in their lower absorption shielding performance. The experimental outputs revealed that absorption shielding effectiveness was enhanced with increasing with proportion of nickel‐zinc ferrite, which pointed out to higher absorption shielding potential of nickel‐zinc ferrite. The physical‐mechanical properties were found not to be influenced by the type of ferrite or ferrites combinations. The higher overall content of ferrites in rubber matrix caused the decrease in tensile characteristics of composites, suggesting that ferrites are inactive fillers considering the physical‐mechanical properties.

Alginate-based gel beads with bigel structures: Preparation, characterization and bioactive encapsulation

The current study developed novel gel beads with bigel structures based on alginate hydrogel and glycerol monostearate oleogel. Bigel beads with different structures were prepared by varying oleogel content, and the beads were also used to co-encapsulate lipophilic and hydrophilic biaoctives. All the beads had high sphericity (>0.94), and the bead size was increased with the increase in oleogel content. Beads with higher content of oleogel had lower shrinking rates and higher level of oil filling the gel pores. The oil droplets were generally acting as inactive fillers in the gel beads, as the mechanical strength (Young's modulus and hardness) was declining with the increase in oleogel content, and no interaction between the oleogel and hydrogel was detected by FTIR. Swelling studies revealed that beads in salt solution at higher temperature had higher swelling ratio, and the increase in oleogel content could inhibit the swelling. The bigel beads were able to encapsulate EGCG and curcumin simultaneously, and beads with higher oleogel content generally had lower encapsulation efficiency of EGCG but higher efficiency of curcumin. The gel structures provided good protection for curcumin, and about 70% of the original curcumin was retained after a 40-day storage test. The study provided novel information regarding the structure-function relationship of the bigel beads, which could be useful for the development of functional food materials.

PEO-Based Solid Composite Polymer Electrolyte for High Capacity Retention All-Solid-State Lithium Metal Battery.

The limited ionic conductivity at room temperature and the constrained electrochemical window of poly(ethylene oxide) (PEO) pose significant obstacles that hinder its broader utilization in high-energy-density lithium metal batteries. The garnet-type material Li6.4 La3 Zr1.4 Ta0.6 O12 (LLZTO) is recognized as a highly promising active filler for enhancing the performance of PEO-based solid polymer electrolytes (SPEs). However, its performance is still limited by its high interfacial resistance. In this study, a novel hybrid filler-designed SPE is employed to achieve excellent electrochemical performance for both the lithium metal anode and the LiFePO4 cathode. The solid composite membrane containing hybrid fillers achieves a maximum ionic conductivity of 1.9 × 10-4 S cm-1 and a Li+ transference number of 0.67 at 40°C, respectively. Additionally, the Li/Li symmetric cells demonstrate a smooth and stable process for 2000 h at a current density of 0.1mA cm-2 . Furthermore, the LiFePO4 /Li battery delivers a high-rate capacity of 159.2 mAh g-1 at 1 C, along with a capacity retention of 95.2% after 400 cycles. These results validate that employing a composite of both active and inactive fillers is an effective strategy for achieving superior performance in all-solid-state lithium metal batteries (ASSLMBs).

Influence of Rapeseed Oil on Extruded Plant-Based Meat Analogues: Assessing Mechanical and Rheological Properties

Successfully replacing meat with plant-based options will require not only replicating the texture of muscular fibres, but also imitating the taste, aroma, and juiciness of meat as closely and realistically as possible. This study examines the impact of rapeseed oil on the textural properties of meat analogues. Pea protein and soy protein are chosen as model systems to assess the effect of rapeseed oil. Optical, mechanical, and rheological characterisation tests are conducted to investigate the oil droplet distribution, the gel strength, Young’s modulus, and the length of the LVE region. The hypothesis is that oil droplets will act as active fillers in the protein matrix, and thus, diminish the strength of the protein gel network. The results of this study show that rapeseed oil droplets act as inactive fillers, as they are not bound to both examined protein matrices. Soy protein extrudates display minimal changes, while pea protein extrudates are significantly affected by the addition of oil. For example, oil addition decreased the G′ in the LVE region of pea protein meat analogues by 50%, while soy protein samples showed no significant changes. Despite the similar interfacial activities of the investigated proteins, the decreased encapsulation efficiency of pea protein was confirmed by the higher amount of extracted oil from the respective extrudates.

Texturing of Soy Yoghurt Alternatives: Pectin Microgel Particles Serve as Inactive Fillers and Weaken the Soy Protein Gel Structure.

Soy-based yoghurt alternatives were highly requested by consumers over the last few years. However, their texture does not always fulfil consumers' demands as such yoghurt alternatives are often perceived as too firm or too soft, sandy, or fibrous. In order to improve the texture, fibres, for example, in the form of microgel particles (MGP), can be added to the soy matrix. MGP are expected to interact with soy proteins, creating different microstructures and, thus, different gel properties after fermentation. In this study, pectin-based MGP were added in different sizes and concentrations, and the soy gel properties after fermentation were characterised. It was found that the addition of 1 wt.% MGP influenced neither the flow behaviour nor the tribological/lubrication properties of the soy matrix, regardless of the MGP size. However, at higher MGP concentrations (3 and 5 wt.%), the viscosity and yield stress were reduced, the gel strength and cross-linking density decreased, and the water-holding capacity was reduced. At 5 wt.%, strong and visible phase separation occurred. Thus, it can be concluded that apple pectin-based MGP serve as inactive fillers in fermented soy protein matrices. They can, therefore, be used to weaken the gel matrix purposely to create novel microstructures.

Influencing Factors of Sulfuric Acid Resistance of Ca-Rich Alkali-Activated Materials

In this paper, we distinguished the degradation of alkali-activated material (AAM) exposed to sulfuric acid as physical (scaling, spalling, cracking, breaking, etc.) and chemical degradation (neutralization), because the mechanisms of these two types of degradation are different. Then, the effects of curing method, raw materials, and their mixing proportions on the two kinds of degradation of AAMs containing GGBFS were investigated in detail, including liquid-filler ratio, component of alkali activator, chemical admixture, inactive filler alternative to fly ash (FA), addition of municipal waste incineration bottom ash (BA), etc. The experimental results show that (a) small liquid-filler ratio, heat-curing, and the use of blended alkali activator solution of sodium silicate and NaOH can reduce both physical and chemical degradation of AAMs; (b) large GGBFS content or AE agent addition decreases the physical degradation, but increases the chemical degradation; (c) using crushed stone powder to replace FA and adding BA or a retarder would increase the physical and chemical degradation; but (d) the use of drying shrinkage reducer composed of polyether derivatives does not affect acid resistance. We also discussed the applicability and limitation of XRD and SEM-EDS in analyzing the chemical compositions of Ca-rich AAMs exposed to sulfuric acid, and found that (e) XRD analysis can identify the gypsum formation, and the gypsum peak intensity is related to the physical degradation of the Ca-rich AAMs; (f) by SEM-EDS analysis, the decalcification and dealkalization of C-A-S-H gels can be judged from the decrease in the average Ca/Si atomic ratio and the average Na atomic percentage in the acid corrosion area, but dealumination can be only determined from the dissimilarity of Al and Si elemental maps; and (g) if the CaO/SO3 molar ratio ranges from 0.8 to 1.0, gypsum formation can be estimated.

Influence of de-structured starch on fine-stranded polymeric and coarse-stranded particulate whey protein gels

This study investigated the phase stability of liquid mixtures and composite gels properties of de-structured waxy potato starch (DWPS) and whey protein isolate (WPI). The DWPS are physically-modified starches treated at 120, 140 and 150 °C for 30 min under constant shear. The composite gels (13% w/w WPI and 4% w/w DWPS) characteristics at pH 7 and pH 5 were evaluated based on their mechanical properties, microstructure, and water-immersion stability. At pH 7, the addition of DWPS did not result in any phase separation. Synergistic gel hardness of WPI was obtained with incorporation of 140 °C DWPS likely due to the enhanced density of a very fine-stranded gel network. The ability of the gel to retain its shape when immersed in water for 40 h was prominent for composite gels containing either gelatinised starch (control) or DWPS samples. In contrast, pure WPI gels and composite gels containing maltodextrin appeared fluid-like and disintegrated gels, respectively. At pH 5, the addition of gelatinised starch or DWPS weakened the particulate protein gels, likely due to phase separation and interrupted protein network with starch polymers acting as an inactive filler. A logarithmically decline in gel hardness was noted as the molar mass of DWPS increased. The coarse porous structure of particulate gels exhibited poor water-holding capacity, low water absorption, and high degree of starch leaching. However, the higher molar mass DWPS polymers enhanced the water-holding capacity of the gels and reduced their own diffusivity from the gel network. • 140 °C DWPS synergistically enhanced the polymeric gel network of WPI. • WPI + DWPS polymeric gels had good shape retention after 40 h water immersion. • Particulate WPI gel strength decreased with increasing molar mass of DWPS samples. • DWPS in particulate WPI gel existed as an inactive filler. • Large molar mass DWPS could disrupt the connectivity of particulate WPI gels.

Influence and effect mechanism of filler type on the physicochemical properties, microbial numbers, and digestibility of ovalbumin emulsion gels during storage.

This study was designed to investigate the influence and effect mechanism of the filler type on the physicochemical properties, microbial numbers, and digestibility of ovalbumin emulsion gels (OEGs) during storage. Sunflower oil was emulsified with ovalbumin (20 mg mL-1) and Tween 80 (20 mg mL-1) separately to prepare ovalbumin emulsion gels (OEGs) that contained active and inactive fillers, respectively. The formed OEGs were stored at 4 °C for 0, 5, 10, 15, and 20 days. The active filler enhanced the gel hardness, water holding capacity, fat holding capacity, and surface hydrophobicity and decreased the digestibility and free sulfhydryl content during storage compared to control (unfilled) ovalbumin gel, whereas the inactive filler had the opposite effects. Protein aggregation diminished, lipid particle aggregation increased, and the amide A band shifted to a higher wavenumber for all three types of gel during storage, suggesting that the compact network structure of the OEG became rough and disordered with storage. The OEG with the active filler did not inhibit microbial growth, and the OEG with the inactive filler did not significantly promote the development of bacteria. In addition, the active filler delayed the in vitro digestion of the protein in the OEG throughout storage. Emulsion gels containing active filler facilitated the retention of the gel properties during storage, whereas emulsion gels containing inactive filler exacerbated the loss of the gel properties during storage.

The Potential Application of Starch and Walnut Shells as Biofillers for Natural Rubber (NR) Composites.

The goal of this study was application of corn starch and ground walnut shells in various amounts by weight as biofillers of natural rubber (NR) biocomposites. Additionally, ionic liquid 1-butyl-3-methylimidazolium chloride (BmiCl) and (3-aminopropyl)-triethoxysilane (APTES) were used to increase the activity of biofillers and to improve the curing characteristics of NR composites. The effect of biofillers used and their modification with aminosilane or ionic liquid on the curing characteristics of NR composites and their functional properties, including crosslink density, mechanical properties in static and dynamic conditions, hardness, thermal stability and resistance to thermo-oxidative aging were investigated. Starch and ground walnut shells were classified as inactive fillers, which can be used alternatively to commercial inactive fillers, e.g., chalk. BmiCl and APTES were successfully used to support the vulcanization and to improve the dispersion of biofillers in NR elastomer matrix. Vulcanizates with starch, especially those containing APTES and BmiCl, exhibited improved tensile properties due to the higher crosslink density and homogenous dispersion of starch, which resulted from BmiCl addition. NR filled with ground walnut shells demonstrated improved resistance to thermo-oxidative aging. It resulted from lignin present in walnut shells, the components of which belong to polyphenols, that have an antioxidant activity.

Rheological properties and microstructure of a novel starch-based emulsion gel produced by one-step emulsion gelation: Effect of oil content

A high elastic starch-based emulsion gel was fabricated by one-step heat-set gelation of the emulsion stabilized by octenylsuccinate starch for the first time. The effect of oil content on the linear and nonlinear rheological behavior and microstructure of the novel emulsion gel was investigated. The role of oil as inactive or active filler in the system shifted depending on content. The oil at low content of 10% did not integrate well into gel matrix and manifested as defects to gel network, playing as inactive filler, which was further confirmed by its decreased rheological modulus and viscoelastic properties compared with pure starch gel. Increasing the oil from 20% to 70% enhanced the gel strength related to a denser packing of oil droplets and starch aggregation, performing as active filler. This work provided a new strategy for structuring liquid oil, and the gel could find applications in food structuring and fat replacer.

Effect of starch concentration and resistant starch filler addition on the physical properties of starch hydrogels.

Corn starch-based hydrogels are safe and biodegradable polymers with a wide array of applications in food science. The aim of this study was to investigate the effects of starch and natural filler resistant starch type 2 (RS2) particles concentration on the textural properties of corn starch hydrogels. Native starch (NS) hydrogels of 8%, 10%, 12%, and 15% w/v were prepared; in each of these dispersions, part of the NS was substituted with RS2 to a concentration of 2% or 10%. NS hydrogels with the highest concentrations had the maximum hardness, cohesiveness, and gumminess values, whereas the addition of RS2 particles did not affect gel textural properties. Native and substituted RS2 hydrogels showed close similarities in their rheological and textural characteristics. Water-holding capacity greatly decreased with increasing starch concentration, suggesting that the hydrogels with the highest NS concentration had the densest network as depicted by SEM micrographs. Subsequently, hardness, gumminess, and consistency coefficient were linearly correlated to starch concentration and storage time. Fluid release was exponentially dependent on starch concentration. The degree of crystallinity by X-ray diffraction (XRD) indicated that by increasing starch concentration and substitution level, crystallinity increased. Consequently, NS concentration determined the textural properties of corn starch hydrogels. On the other hand, RS2 substitutions did not affect any of these parameters, indicating their potential role as inactive fillers with a beneficial effect on the maintenance of normal blood glucose levels. Therefore, the consistency of a food gel can be optimized by changing the ratio of inactive filler to starch gel matrix.

Effect of synthesis parameters on the development of unconfined compressive strength of recycled waste concrete powder-based geopolymers

The main object of this study is to investigate the geopolymerization potential of recycled waste concrete powder (RWCP) as well as the effects of synthesis parameters, including the molarity of NaOH solution, the mass ratio of water glass to NaOH solution (WG/NH), the mass ratio of liquid alkali activator to solid powder (L/S), and the curing conditions (curing temperature, curing time and curing method), on the development of unconfined compressive strength (UCS) of recycled waste concrete powder-based geopolymers. The recycled waste concrete powder (RWCP) (size < 0.075 mm) was utilized as source material, and water glass and sodium hydroxide (NaOH) were used as alkaline activators to synthesize geopolymer specimens. The dissolution of alumino-silicate from the RWCP under different concentrations of alkaline solutions was studied. The UCS of the resulting geopolymers synthesized under different conditions was tested. Further, the microstructure and mineral composition of the final products were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) technology. The results indicate that the dissolution of Si4+ and Al3+ in raw materials (RWCP) was highly affected by the alkali content and dissolution time. Increasing the alkali content, water glass content and L/S ratio was all conducive to enhancing the UCS of geopolymers. The optimum NaOH concentration corresponpded to 14 mol/L, WG/NH ratio of 1.5 and L/S mass ratio of 0.4. A maximum 7-day UCS of 14.32 MPa was achieved by wet curing at 70 ℃ for 24 hours. Microscopic analysis showed that the final products were mainly composed of amorphous hydrated calcium silicate and hydrated sodium aluminosilicate gels. However, due to the low activity and high calcium content of RWCP, most of crystalline phases and some unreacted substances still existed in the end products as inactive fillers, resulting in a relatively low UCS of the synthesized geopolymers. Baded on the research, it can be concluded that RWCP can be recycled as the precursor to synthesize geopolymer binder.

The effect of interfacial interactions on the rheology of water in oil emulsions oleogelled by candelilla wax and saturated triacylglycerols

The effects of water-oil interfacial activity of candelilla wax (CW), glycerol monopalmitate (GMP), glycerol monooleate (GMO) and polyglycerol-polyricinoleate (PGPR) on the microstructure and rheology of W/O emulsions oleogelled with CW and fully hydrogenated soybean oil (FH) was investigated. The emulsifier with the highest interfacial activity was PGPR, followed by GMO, and GMP. Polar compounds of CW (CW-PC) also displayed interfacial activity. Interfacial interactions of the continuous lipid crystal network with the CW-PC and PGPR in W/O emulsions decreased the elastic modulus (G′) as the aqueous phase (AP) increased, indicating the water droplets behaved as inactive filler due to a weak interaction with the continuous phase. In contrast, the CW-PC and the monoglycerides had a cooperative interaction on the interfacial tension reduction. W/O emulsions produced with monoglycerols maintained or increased their G′ as the AP increased, denoting a strong interaction of water droplets and the continuous phase (i.e., active filler behavior). At constant content of AP and FH, G′ of emulsions tended to decline as the PGPR content increased, while the opposite was observed with emulsions produced with GMO. Adding 10% FH to the emulsions magnified both the active and inactive filler effects produced by GMO and PGPR, respectively.

Electromagnetic Interference Shielding and Physical-Mechanical Characteristics of Rubber Composites Filled with Manganese-Zinc Ferrite and Carbon Black.

In the present work, composite materials were prepared by incorporation of manganese-zinc ferrite, carbon black and combination of ferrite and carbon black into acrylonitrile-butadiene rubber (NBR). For cross-linking of composites, standard sulfur-based curing system was applied. The main goal was to investigate the influence of the fillers on the physical-mechanical properties of composites. Then, the electromagnetic absorption shielding ability was investigated in the frequency range 1 MHz–3 GHz. The results revealed that composites filled with ferrite provide sufficient absorption shielding performance in the tested frequency range. On the other hand, ferrite behaves as an inactive filler and deteriorates the physical-mechanical characteristics of composites. Carbon black reinforces the rubber matrix and contributes to the improvement of physical-mechanical properties. However, composites filled with carbon black are not able to absorb electromagnetic radiation in the given frequency range. Finally, the combination of carbon black and ferrite resulted in the modification of both physical-mechanical characteristics and absorption shielding ability of hybrid composites.

Rheological Properties and Fillers Dispersion State in the Elastomer Magnetic Composites

AbstractManganese‐zinc ferrite as magnetic filler is compounded with NBR or NR based elastomer matrices in two steps. Manganese‐zinc ferrite is the most important part of elastomer compounds because of its magnetic properties, but it is inactive filler and thus carbon black is added into the rubber formulations as well. The rubber compound filled only with ferrite exhibits high viscosity and it is not able to be processed by extrusion. For this reason, rheological properties of all compounds with different ratio of processing additives and fillers are studied. It has been found out in our previous research that rubber compounds filled with 200 phr of ferrite showed the best electromagnetic shielding performance. Dispersion Z and dispersion D of cured and uncured elastomer compounds with processing additives Werbablend and Werbalub, which are mixed in laboratory and industrial kneading machine, are determined on an instrument disperGRADERTM αview.