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Composites revolutionize material performance, fostering innovation and efficiency in diverse sectors. Elastomer-based polymeric composites are crucial for applications requiring superior mechanical strength and durability. Widely applied in automotives, aerospace, construction, and consumer goods, they excel under extreme conditions. Composites based on recycled rubber, fortified with reinforcing fillers, represent a sustainable material innovation by repurposing discarded rubber. The integration of reinforcing agents enhances the strength and resilience of this composite, and the recycled polymeric matrix offers an eco-friendly alternative to virgin elastomers, reducing their environmental impact. Devulcanized rubber, with inherently lower mechanical properties than virgin rubber, requires enhancement of its quality for reuse in a circular economy: considerable amounts of recycled tire rubber can only be applied in new tires if the property profile comes close to the one of the virgin rubber. To achieve this, model passenger car tire and whole tire rubber granulates were transformed into elastomeric composites through optimized devulcanization and blending with additional fillers like carbon black and silica–silane. These fillers were chosen as they are commonly used in tire compounding, but they lose their reactivity during their service life and the devulcanization process. Incorporation of 20% (w/w) additional filler enhanced the strength of the devulcanizate composites by up to 15%. Additionally, increased silane concentration significantly further improved the tensile strength, Payne effect, and dispersion by enhancing the polymer–filler interaction through improved silanization. Higher silane concentrations reduced elongation at break and increased crosslink density, as it leads to a stable filler–polymer network. The optimal concentration of a silica–silane filler system for a devulcanizate was found to be 20% silica with 3% silane, showing the best property profile. [ABSTRACT FROM AUTHOR]

To understand the effects of additives on the properties of rubber grades suitable for sealing applications in high-pressure H 2 gas infrastructure, five acrylonitrile butadiene rubber (NBR) vulcanizates with different fillers and curing agents are investigated. Structure-property relationships of these grades are correlated with the additives and properties required for high-pressure gas atmospheres are evaluated. Further, the influence of the exposure to high-pressure hydrogen, i.e., hydrogen uptake and morphological changes after exposure, is evaluated. With the addition of a silica filler and a coupling agent for improved filler-matrix interfaces, similar overall properties, e.g. crosslink density, tensile strength, and storage modulus are obtained, compared to a carbon black (CB) filled grade. Density reduction after hydrogen exposure is significantly higher for CB-filled NBR, indicating higher hydrogen uptake in CB-filled rubber compared to silica filled NBR grades, or slower gas desorption. However, CB-filled specimens show to be less prone to filler migration than the silica-filled samples. • Effects of NBR formulations on properties for high-pressure gas systems were tested. • Functionalized silica enhances typical properties to a comparable range like CB. • The balance of additives results in suitable RGD performance. • Silica filled NBR shows lower H 2 uptake compared to non-plasticized CB filled NBR. • Morphology of CB filled NBR is less affected by H 2 than silica filled grades. [ABSTRACT FROM AUTHOR]

This study employs potassium ferrate (K2FeO4) for the oxidation treatment of multi‐walled carbon nanotubes (MWNTs) under neutral and acidic conditions. A wet flash evaporation process is utilized to prepare natural rubber/MWNTs/carbon black composites, enhancing the performance of rubber composites. The increased oxidation level of MWNTs enhances their hydrophilicity, increases the quantity of oxygen‐containing hydroxyl groups on the surface, promotes dispersion within the natural rubber matrix, and ultimately improves the performance of the rubber products. The effective dispersion of MWNTs reduces electron transport resistance, forming a favorable electron transport channel in natural rubber. Experimental results indicate that K2FeO4 achieves the highest oxidation degree and optimal performance in an acidic environment. Compared to untreated MWNTs rubber composites, the oxidized MWNTs rubber composites exhibit a 34.9% reduction in the Payne effect, a 15.7% decrease in wear, a 12.7% reduction in rolling resistance, and a two‐order‐of‐magnitude increase in conductivity. This study provides a novel approach for preparing water‐dispersible MWNTs and high‐performance rubber composites, holding potential applications in premium rubber products and conductive rubber fields. Highlights: The wet flash refining process improved the dispersion of MWNTs.K2FeO4 oxidation of MWNTs was enhanced under acidic conditions.Oxidized MWNTs combined with CB to form a CB‐MWNTs‐CB filler network.Oxidized MWNTs and CB increased the "ball‐chain" arrangement in NR. [ABSTRACT FROM AUTHOR]

During and after the COVID-19 pandemic, the world has become more aware of environmental concerns and the importance of sustainability. Using natural rubber instead of synthetic rubber is one step toward a greener environment in a variety of technological applications, including the fabrication of vehicle tires. The objective of this work is to optimize the formulation for the production of airless tires, primarily for military vehicle applications, using natural rubber. Two natural rubber types, SIR 20 and RSS 1, with carbon black variants N220 and N550 as reinforcing agents present novel synergistic effects, and potentially tailor the properties of the rubber compound more precisely to meet the demanding requirements of military vehicle tires. A comprehensive assessment was conducted to evaluate various physical, damping, processing, and mechanical properties under standard conditions and subsequent aging at 70 °C for 72 h. Comparative analysis against control samples revealed notable improvements, particularly in abrasion resistance, crucial for tire wear. The combination of RSS 1 and CB N220 showed significant enhancements in strength and rigidity, suggesting their viability as alternative fillers. Leveraging dynamic mechanical analysis (DMA) results, the rubber compound underwent optimization to meet airless tire requirements, encompassing durability, comfort, and performance. This nuanced understanding of rubber's viscoelastic behavior holds paramount importance in designing puncture-resistant airless tires with optimal performance attributes. Combination of innovative materials and advanced characterization techniques to address the specific challenges of enhancing airless tire performance for military vehicles in challenging operational environments. [ABSTRACT FROM AUTHOR]

In this paper, the effect of non‐relaxing torsion loadings on the fatigue lifetime reinforcement of carbon black filled natural rubber is fully addressed. Torsion fatigue tests with different loading ratios have been performed with highly notched axisymmetric‐shaped specimens. Finite element analysis is used to predict the mechanical state at any point in the specimens. The prediction is significantly improved by taking into account the heterogeneous accommodation. The first Haigh diagram under fatigue torsion is built and analyzed by calculating the minimum loading in terms of the Cauchy stress as the normal stress to the crack for the minimum angle prescribed during the cycle. A strong lifetime reinforcement has been observed, which is found to be of the same amplitude to the one obtained under uniaxial tension with the same material. This has been confirmed by specific tests that combined non‐relaxing torsion and non‐relaxing tension loadings. Post‐mortem analysis carried out at the macroscopic and the microscopic scales enabled us to identify damage mechanisms, especially in the cases where the lifetime reinforcement was observed. [ABSTRACT FROM AUTHOR]

To elucidate the specific mechanical impact of carbon black (CB) filler–rubber interactions on reinforcement, CB particles are subjected to graphitization at 1300 °C and oxidation through concentrated nitric acid treatment to modulate their surface activity. Alongside untreated CB particles, the influence of surface activity and the oxygen distribution are investigated to assess their role in shaping CB aggregate structures using X‐ray absorption spectrum (XAS) and X‐ray computed tomography (CT) with spatial resolution of 30 nm. Meanwhile, virgin and modified CBs are blended in natural rubber with varying amounts (10, 30, 50 phr) and the aggregates distributions in rubber are investigated by nano‐CT. Combined with the mechanical properties of rubber composites and parameters of filler networks, the mechanical contributions arising from filler–rubber interactions are quantified. The findings underscore the robust interactions between oxidized CB and rubber matrix, exhibiting a mechanical property enhancement ratio of ≈59.2% at low strains in comparison to normal CB filler. The results indicate the synergies encompass of filler network, rubber chains, and filler–rubber interactions all play important roles for reinforcement, which aligns with the broader understanding of filler–rubber interactions and CB reinforcement mechanisms. [ABSTRACT FROM AUTHOR]

Nanoparticle (NP)‐filled natural rubber (NR) has attracted much attention owing to their prominent mechanical strength, stiffness, and wear resistance. In this study, the static and dynamic mechanical properties of carbon black (CB)/carbon nanotubes (CNTs) hybrid filled NR nanocomposites are investigated using coarse‐grained molecular dynamics (CGMD) simulations. The non‐bonded coarse‐grained force fields for the CB/CNTs hybrid filled NR nanocomposites are constructed by combining several methods (i.e., effective force coarse‐graining, iterative Boltzmann inversion, and energy matching methods). The uniaxial tensile results indicate that the gradual replacement of CB by the same weight percentage of CNTs significantly improves the mechanical performances of the nanocomposites and increases the heterogeneity of the stress and strain distributions in the nanocomposites, which can be ascribed to the high mechanical strength of CNTs and the formation of the rigid interface networks between CNTs and the NR matrix due to the wrapping behavior of NR molecular chains on the surface of CNTs. Furthermore, the dynamic shear results demonstrate that the introduction of NPs significantly enhances the Payne effect of the nanocomposites, and the higher the CNT loading in hybrid NPs, the stronger the Payne effect. It is also found that the breakup of NP networks plays a dominant role for the Payne effect of filled rubber as compared to the interfacial separation between NPs and the rubber matrix. The present multiscale computational framework can be further extended to other polymer nanocomposites, and sheds new light on the design and exploration of polymer nanocomposites through bottom‐up prediction. [ABSTRACT FROM AUTHOR]

This study investigated the synergistic effect of carbon black/multi-wall carbon nanotube (CB/MWCNT) hybrid fillers on the physical and mechanical properties of Ethylene propylene diene rubber (EPDM) composites after exposure to high-pressure hydrogen gas. The EPDM/CB/CNT hybrid composites were prepared by using the EPDM/MWCNT master batch (MB) with 10 phr CNTs to enhance the dispersion of CNTs in hybrid composites. The investigation included a detailed analysis of cure characteristics, crosslink density, Payne effect, mechanical properties, and hydrogen permeation properties. After exposure to 96.3 MPa hydrogen gas, the hydrogen uptake and the change in volume and mechanical properties of the composites were assessed. We found that as the MWCNT volume fraction in fillers increased, the crosslink density, filler–filler interaction, and modulus of hybrid composites increased. The hydrogen uptake and the solubility of the composites decreased with an increasing MWCNT volume fraction in fillers. Moreover, after exposure to hydrogen gas, the change in volume and mechanical properties exhibited a diminishing trend with a higher MWCNT volume fraction. We conclude that the hybridization of CB and CNTs formed strong filler–filler networks in hybrid composites, consequently reinforcing the EPDM composites and enhancing the barrier properties of hydrogen gas. [ABSTRACT FROM AUTHOR]

It has attracted tremendous attention for replacing petroleum‐based carbon black or mineral fillers with renewable, biology‐based and low‐cost cellulose. However, the reinforcing effect of cellulose, especially at the microscale, is still a great challenge in the polymer industry. In this work, a feasible surface modification method for microcrystalline cellulose powder (MCC) in all solid states is proposed by using rubber accelerators N‐cyclohexyl benzothiazole‐2‐sulphenamidee (CBS) and 2,2′‐dibenzothiazoledisulfide (DM). These accelerators not only accelerate the sulfur crosslink of nitrile butadiene rubber (NBR), but also graft to rubber molecular chains and form hydrogen bonds with MCC, resulting in good interfacial interaction and good dispersion of MCC in the NBR matrix. As a consequence, the tensile strength and elongation at break of NBR/10MCC reach up to 20.12 MPa and 511%, respectively, which are the highest values of NBR/MCC or cellulose nanocrystals (CNCs) composites we can find in the world and are comparable to those of carbon black or mineral fillers. This provides a more effective and environmentally friendly way of using MCC or CNCs in the polymer industry. Highlights: Microcrystalline cellulose powder can reinforce NBR.Hydrogen bonds have been established between accelerators and MCC.The tensile strength of NBR/10MCC composite reaches 20 MPa.The reinforcing mechanism is ascribed to the immobilized rubber layer. [ABSTRACT FROM AUTHOR]

The present research outlines the novel finite element analysis of green tire tread compounds based on solution styrene‐butadiene rubber/butadiene rubber (SSBR/BR) reinforced with a hybrid silica/carbon black filler system. For this purpose, a series of micromodels using representative volume elements (RVEs) were developed. The silica/carbon black ratio with a constant value of the reinforcement and considering periodic boundary conditions (PBCs) were established. The distribution of the reinforcing fillers in the matrix was inspired by transmission electron microscope (TEM) micrographs. A nonlinear hyperviscoelastic model was considered for the matrix and interphase zones and a linear elastic model for the reinforcement phase to predict the dissipation behavior at a moderate to high strain regime. To confirm the accuracy of the proposed model, the RVEs of hybrid systems were simulated and then compared with experimental data. The results showed that the proposed model is capable to predict the mechanical properties of rubber compounds. The presence of agglomerated fillers resulted in an increase in the dissipation behavior. This was confirmed by rubber process analyzer (RPA) and dynamic mechanical thermal analysis (DMTA) results. Highlights: Rubber compounds based on SSBR/BR reinforced with silica and/or carbon black were prepared by the melt mixing method.A multi‐scale finite element analysis of the particulate composites was developed using RVE.The distribution of reinforcing fillers in the matrix was inspired by TEM.The prediction of the stress–strain behavior of the hybrid composites was confirmed by the results of tensile tests.The simulated dissipation behavior of the composites was compared with RPA and DMTA analyses. [ABSTRACT FROM AUTHOR]

The partial or total replacement of carbon black by silica fillers is initiated through various techniques for environment-friendly, smart, and fuel-efficient NR composites for high-end dynamic applications like tyre tread. The smart properties such as low rolling resistance, better wet skid resistance, and abrasion resistance as well as noise reduction, create tyre tread compounds with superior performance. The endeavour to maximise the incorporation of eco-friendly ingredients like silica filler in rubber compound associates to produce a green tyre product indeed. The present review encompasses those approaches with a substantial contribution in the area along with critical insights in the respective efforts. Initially, the various types of commercially available silica fillers are discussed in brief, followed by the various approaches for surface modification in detail. Finally, the miscellaneous initiatives along with their achievements and drawbacks are included under five strategic verticals for better understanding along with vital remarks. [ABSTRACT FROM AUTHOR]

Rubber–metal parts inside the car require rubber compounds capable of ensuring optimal function and maximum service life without interface delamination. From this perspective, the strength of the bond which is created by the chemical interaction of rubber and metal by an adhesive is decisive for ensuring the functionality of the entire compound. It is dependent not only on the choice of the right adhesive but also on the rubber compound ingredients and their amount. Here, the influence of different types of carbon blacks as well as different curing systems in combination with a commonly used adhesive is described. The durability of the metal–adhesive–rubber bond is characterized by a specially designed shear strength analysis under quasi-static loading, whereas a significant influence of the structure of the carbon black has shown. It has also been observed that the presence of monosulphidic bonds has a positive effect on the shear strength. [ABSTRACT FROM AUTHOR]

Biomass renewable fiber has the advantages of low cost and environmental friendliness; however, its application as a reinforcement material is limited owing to its poor reinforcement effect. Thus, expanding its application is still a major challenge. This study investigates the effect of hemp fiber (HF) of different lengths on the mechanical properties and fatigue behavior of styrene-butadiene rubber/carbon black (SBR/CB) compounds using high-pressure low-shear extrusion. The results showed that the length of the HF retained by the extrusion process was approximately 10 times that of the traditional internal mixing process (internal mixing and open mixing). Interface bonding between the long HF coated with butadiene-vinyl pyridine latex (VPL) and the SBR/CB matrix was improved significantly. This inhibited the fatigue-crack propagation and considerably improved the dynamic fatigue life of the notched specimens. The dynamic fatigue life of the notched specimens of the composite prepared by the extrusion process was approximately nine times longer than that of the traditional internal mixing process. The results showed that the long HF length retained after the extrusion process effectively enhanced the strength of the rubber composites and significantly improved the dynamic fatigue life of rubber products under alternating stress. Highlights • The raw material, hemp fiber, is a renewable resource, low cost and environmentally friendly. • Pioneering a new process for preparing rubber composite materials, replacing the traditional process for preparing composite materials. • High-pressure, low-shear extrusion process retains the length of the hemp fibers and improves rubber composites properties. • Compared to traditional processes, long fiber length is 10 times longer by the extrusion process and fatigue life is increased to 9 times. • High-pressure, low-shear extrusion process enables mass production, opening up new ideas for rubber industrial production. [ABSTRACT FROM AUTHOR]

Three types of composites were tested for electromagnetic interference (EMI) absorption shielding effectiveness, the curing process, and their physical–mechanical properties. For the first type of composites, nickel–zinc ferrite, manganese–zinc ferrite, and both fillers in their mutual combinations were incorporated into acrylonitrile–butadiene rubber. The overall content of the filler, or fillers, was kept at 200 phr. Then, carbon black or carbon fibers were incorporated into each rubber formulation at a constant loading of—25 phr, while the content of magnetic fillers was unchanged, at —200 phr. This work focused on the understanding of correlations between the electromagnetic shielding parameters and electrical conductivity of composites in relation to their EMI absorption shielding effectiveness. The absorption shielding abilities of materials were evaluated within a frequency bandwidth from 1 MHz to 6 GHz. This study revealed good correlation among permittivity, conductivity, and EMI absorption effectiveness. Although the absorption shielding efficiency of composites filled only with ferrites seems to be the highest, the absorption maxima of those composites reached over 6 GHz. The application of carbon-based fillers resulted in the higher electrical conductivity and higher permittivity of composites, which was reflected in their lower absorption shielding performance. However, the composites filled with ferrites and carbon-based fillers absorbed electromagnetic radiation within the desired frequency range. The presence of carbon-based fillers caused improvement in the tensile behavior of composites. This study also demonstrated that the higher the ratio of nickel–zinc ferrite in combined magnetic fillers, the better the absorption shielding efficiency. [ABSTRACT FROM AUTHOR]

Graphene and its derivatives have been confirmed to be among the best fillers for rubber due to their excellent properties, such as high mechanical strength, improved interface interaction, and strain-induced crystallization capabilities. Graphene rubber materials can be widely used in tires, shoes, high-barrier conductive seals, electromagnetic shielding seals, shock absorbers, etc. In order to reduce the graphene loading and endow more desirable functions to rubber materials, graphene-based hybrid fillers are extensively employed, which can effectively enhance the performance of rubber composites. This review briefly summarizes the recent research on rubber composites with graphene-based hybrid fillers consisting of carbon black, silica, carbon nanotubes, metal oxide, and one-dimensional nanowires. The preparation methods, performance improvements, and applications of different graphene-based hybrid fillers/rubber composites have been investigated. This study also focuses on methods that can ensure the effectiveness of graphene hybrid fillers in reinforcing rubber composites. Furthermore, the enhanced mechanism of graphene- and graphene derivative-based hybrid fillers in rubber composites is investigated to provide a foundation for future studies. [ABSTRACT FROM AUTHOR]

Increasing industrialization and rapid change in market demand has led to aggressive competition impacting both business and environmental sustainability globally. In view of the new legislations, regulations and restrictions on the usage of hazardous materials, it becomes mandatory to use eco-friendly materials. In the present work, various petroleum-based and different modified vegetable oils are characterised for chemical and analytical properties. Styrene butadiene rubber (SBR) is extended with these oils at laboratory scale through emulsion polymerisation technique. Totally four number of petroleum-based oils like distillate aromatic extract (DAE), treated distillate aromatic extract (TDAE), residual aromatic extract (RAE) and naphthenic type oil and two number of modified vegetable oils, NO_2 and NO_6, are evaluated. All oils have shown compatibility with SBR latex which is confirmed by checking solvent extractables as well as oil leaching checking by visual inspection of oil extended rubber samples. These raw rubber samples are characterised for raw rubber properties as well as in ASTM-based rubber compound recipe to check their processing behaviour. Compounds prepared with both vegetable oil-based styrene butadiene rubber have shown comparable or slightly better processing properties as compared to compounds prepared with petroleum oil-based rubbers. Experimental compounds are also showing comparable carbon black dispersion and better polymer–filler interaction which may be due to the presence of various surface functional groups in vegetable oils. Microscopic pictures also confirm the comparable carbon black dispersion for all the samples. [ABSTRACT FROM AUTHOR]

The aim of the presented work was to obtain a new type of homogeneous composite based on an industrial polymer (polybutadiene, PB) and a well-known inexpensive filler (carbon black P-234, CB). For this purpose, the reaction of oxidative chlorophosphorylation (OxCh) was used. This makes it possible to introduce CB into the cross-linked structure of the modified polymer and ensure optimal distribution of the filler in it. The structure and thermal stability of the composite synthesized by the OxCh reaction were studied. Analysis of the composite by Fourier-transform infrared spectroscopy indicates a uniform distribution of carbon black in the network structure of the matrix and the physical interaction of the phases of the composite. Ultraviolet-visible spectrum data confirmed the improvement in light absorption in a wide range of the electromagnetic spectrum and the decrease in the optical band gap energy of the phosphochlorinated PB (PhPB) matrix with the addition of CB (Eg of PhPB = 3.25 eV; Eg of PhPB/CB composite = 2.28 eV). The influence of CB on the thermal stability of the PhPB matrix was studied using thermogravimetric and differential thermogravimetric analysis. After thermal analysis, the char yield for PhPB was 41 wt. %, and for PhPB/CB composite was 35.2 wt. %. Compared to PhPB, the increase in char yield, the decrease in maximum thermal decomposition temperature, and the high-integrated thermal decomposition temperature for the PhPB/CB composite show the improvement in the thermal stability of PhPB due to CB. [ABSTRACT FROM AUTHOR]

Waste from scrap tyres, due to its high volume (17 million Mg per year) and durability resulting from the physical and chemical properties, requires innovative approaches for efficient and environmentally friendly management. In many countries, the landfilling of waste tyres is banned (e.g., EU, USA, UK); however, waste tyres can be a source of valuable materials such as carbon black, pyrolysis oil, hydrogen-rich syngas, tyre char, as well as energy. The purpose of this article is to provide a synthesis of the state of knowledge regarding the thermal conversion of waste tyres by pyrolysis and gasification, taking into account the use of different measurement techniques and reactor types. These technologies are forward-looking and have a high degree of flexibility in terms of product sourcing, depending on the process conditions. The properties of waste from used tyres were analysed, i.e., the composition of the content of individual components and the main chemical substances. The results encompassed ultimate and proximate analyses of rubber from tyres, as well as the physical and chemical parameters of the tyre char obtained through pyrolysis. This article compiles available literature data regarding the impact of process and raw material parameters, such as temperature and time conditions, pressure, particle size, and catalyst addition on the pyrolysis and gasification processes. It also explores the influence of these factors on the yield and properties of the products, including pyrolysis oil, gas, synthesis gas, and tyre char. [ABSTRACT FROM AUTHOR]

The development of thermally conductive rubber nanocomposites for heat management poses a formidable challenge in numerous applications, notably within the realm of tire technology. Notably, rubber materials are characterized by their inherently low thermal conductivity. Consequently, it becomes imperative to incorporate diverse conductive fillers to mitigate the propensity for heat build-up. Multi-walled carbon nanotubes (MWCNTs), as reinforcement agents within the tire tread compounds, have gained considerable attention owing to their extraordinary attributes. The attainment of high-performance rubber nanocomposites hinges significantly on the uniform distribution of MWCNT. This study presents the influence of MWCNTs on the performance of carbon black (CB)-reinforced natural rubber (NR)/styrene butadiene rubber (SBR) tire compounds prepared via high shear melt mixing. Morphological analysis showed a good distribution of MWCNTs in the NR/SBR/CB compound. The vulcanization parameters, such as the maximum and minimum torque, cross-linking density, hardness, abrasion resistance, tensile strength, and Young modulus, exhibited a progressive improvement with the addition of MWCNT. Remarkably, adding MWCNT into CB improved the heat conductivity of the NR/SBR/CB compounds, hence decreasing the heat build-up. A percolation mode was also proposed for the hybrid carbon fillers based on the data obtained. [ABSTRACT FROM AUTHOR]

Incorporation of carbon black (CB) in natural rubber (NR) enhances the Mullins effect and Payne effect of their vulcanizates, but the strain softening mechanisms and the microstructure evolution in the vulcanizates have not been clearly concluded so far. We investigate the Mullins effect and Payne effect of CB filled NR vulcanizates by using cyclic tensile tests at different temperatures and dynamic rheological measurements combined with simultaneous electric conduction. During cyclic stretching, the normalized recovery hysteresis energy and accumulative softening energy for NR/CB vulcanizates with different loadings can be both superimposed on a master curve, indicating that the Mullins effect is mainly dominated by the rubber matrix. The irreversible simultaneous resistance evolution also reveals that the structural evolution of nanoparticles (NPs) network is not directly related to the Mullins effect. Moreover, the extension of linear viscoelastic region and the hysteresis of Payne effect for filled vulcanizates subjected to cyclic stretching indicate the destruction of CB aggregated structure and the interfacial layers between CB and rubber chains during cyclic stretching. This investigation would be illuminating for the microstructure evolution and strain softening of rubber nanocomposites under harsh service conditions. [ABSTRACT FROM AUTHOR]

Manganese–zinc ferrite, nickel-zinc ferrite and the combination of both fillers were used for fabrication of composites. Then, carbon black was applied in combination with ferrites in the second type of composites. The main goal was to investigate the influence of fillers on absorption shielding efficiency and physical–mechanical properties of composites. It was revealed that incorporation of ferrites into rubber matrix leads to fabrication of composites that are able to absorb electromagnetic radiation. The higher was the amount of nickel-zinc ferrite in fillers combinations, the higher was the absorption shielding performance of composites. The results showed that nickel-zinc ferrite demonstrated better absorption shielding potential. The absorption shielding efficiency of composites filled with carbon black and ferrites was lower when compared to equivalent composites filled only with ferrites, which can be attributed to higher electrical conductivity of composites due to the presence of carbon black. On the other side, the incorporation of carbon black caused the improvement in physical–mechanical properties of composites, mainly the enhancement of the tensile strength, modulus and hardness. [ABSTRACT FROM AUTHOR]

• BR/VMQ blends filled with carbon black are promising compounds for Mars environment applications. • Radiation resistance of the CBs-filled BR/VMQ blends is very high allowing for long-term utilization on Mars. • Low glass transition temperatures of the BR and VMQ allow the application of the blends in most of Mars' temperature range. A growing interest in Mars exploration calls for new solutions as an increasing mass of rovers causes their metal alloy wheels to experience serious damage. Martian conditions including temperatures as low as −120 °C and destructive ionizing radiation effectively rule out rubber materials currently used on Earth. This study aims to design and test rubber compounds capable of withstanding harsh Martian conditions while providing good damping properties and remaining elastic in extremely low temperatures. The prepared compounds contained two elastomers – butadiene (BR) and silicone rubber (VMQ) – which both show appropriately low glass transition temperatures. Mixing of the rubbers provided blends combining properties desirable for Martian applications. For better miscibility and chemical coupling trimethylolpropane tris(3-mercaptopropionate) compatibilizer containing three thiol groups was incorporated. Additionally, to improve mechanical properties and as a free radical scavenger, carbon black (CB) fillers were used. The properties of compounds with and without the addition of the compatibilizer were evaluated. Obtained data shows the great potential of the BR/VMQ blends for future Martian applications. [ABSTRACT FROM AUTHOR]

As a promising renewable resource, waste tire rubber powder has been utilized to enhance asphalt performance but it has compatibility concerns with matrix asphalt. To solve the phase separation between crumb tire rubber (CTR) and asphalt, waste cooking oil (WCO) has been successfully employed as the solvent to desulfurize crumb rubber. However, about 30 % of carbon black is wrapped in crumb rubber, which has a high recycling value. The cross-linking network structure of the crumb rubber can be loosened by waste cooking oil, and the carbon black will gradually peel off. This study desulfurizes crumb rubber with waste cooking oil at 180 ℃, and the carbon black produced by the evolution of rubber structure was separated by Soxhlet extraction. The rubber-cracked carbon black (RCCB) and the industrial carbon black N330 were added to asphalt, and the impact of the two different carbon black on the anti-deformation of asphalt was analyzed by dynamic shear rheometer (DSR). The results indicated that at the same dosage of 5 %, the carbon black separated from rubber will weaken the deformation resistance of asphalt at high temperatures, rather than improving it like N330 produced in the industry. [ABSTRACT FROM AUTHOR]

Epoxidized Natural Rubber (ENR) is a specialty rubber produced by modification of natural rubber (NR) latex. In this study, the effects of vulcanisation temperature on the vulcanisation characteristics and vulcanisation kinetics of ENR compounds were studied. A Monsanto Moving Die Rheometer (MDR2000) was used, with vulcanisation temperatures ranging from 140 to 180 °C considered. Unfilled ENR and NR compounds were compared to filled compounds, in which carbon black and silica fillers were used. All compounds' optimal vulcanisation time (t95), curing rate index (CRI), percentage of reversal (R300) and vulcanisation kinetics were investigated. It can be shown that for both filled and unfilled compounds, ENR has a shorter t95, a higher CRI, and a higher R300 than NR. Furthermore, higher vulcanisation temperatures decreased the t95, with increased CRI and enhanced R300 for all compounds. It was observed that ENR tended to have lower activation energy, Ea than NR for both filled and unfilled compounds and among the compounds examined, silica-filled ENR showed the highest activation energy value. [ABSTRACT FROM AUTHOR]

In this paper, walnut shell filler of 75–150 µm and 45–75 µm size was used in rubber compound with different loadings (2,3, and 5 phr). At 2, 3, and 5 phr loading, small-size WNS powder (45–75 µm) has higher modulus at 300%, tensile strength and elongation at break than larger-size powder (75–150 µm); however, modulus at 300% is lower than blank compound. As the amount of WNS filler increases, the elongation at break with modulus at 300% and tensile strength decrease. The goal of using silane is to improve the interfacial interaction between WNS filler and the rubber matrix. Larger-size WNS filler using Si69 compound demonstrated higher modulus at 300% with higher elongation at break and tensile strength compared to non-silanised compound; however, modulus at 300% remained lower than blank compound. The silanised compound with both WNS fillers demonstrated slightly higher rebound resilience at 100 °C, slightly lower heat build-up, and slightly lower tan delta at 60 °C than the blank compound. It was demonstrated that small-size WNS filler with silane could partially replace N330 carbon black (3 phr) in natural rubber-based tire tread compound due to its bio-based, biodegradable, renewable and sustainable properties. [ABSTRACT FROM AUTHOR]

Carbon black is a very important reinforcing agent for rubber, which can significantly improve rubber modulus, strength, and abrasion performance. However, there are defects such as large hysteresis loss, dynamic energy loss, and high heat build‐up by using carbon black to reinforce rubber. In this paper, a new silane coupling agent named M1 was prepared and introduced as the coupling agent of carbon black, and M1 modified carbon black was prepared. The Fourier transform infrared spectroscopy, thermogravimetric analysis, and X‐ray photoelectron spectrometer results demonstrated the successful modification and revealed the interaction mechanism between M1 and carbon black. The results showed that strong interfacial bonding can be generated between M1 and carbon black through physical and chemical interactions, thereby promoting the dispersion of carbon black in the rubber matrix. Then, carbon black/rubber nanocomposites were prepared with different amount of M1. Because M1 could improve the dispersion of carbon black in the rubber matrix, the carbon black/rubber nanocomposites with M1 have lower network and loss factor, lower rolling resistance, and higher abrasion resistance, which is ideal to manufacture green bus and truck tires for energy‐saving, environment‐friendly, and low‐carbon society. [ABSTRACT FROM AUTHOR]

A strain sensor was prepared by reinforcing acrylonitrile butadiene rubber (NBR)-5 parts per hundred of rubber (phr) carbon black (CBH) separately with small concentration (∼0.1phr) of reduced graphene oxide (GL), multi-walled, and carbon nanotube (NTL) via a combination of conventional solution and solid processing techniques. The interactions and the electronic properties among carbon based fillers NT, CB, G and their synergy effects (NBR-CBH-GL and NBR-CBH-NTL) were investigated by using density functional theory (DFT) modeling approach. The DFT predictions were in correspondence with the experimental results. The optimum design (NBR-CBH-GL) was found to show high curing, mechanical and improved electrical properties. On account of strain sensing performance, NBR-CBH-GL exhibited high gauge factor (GF) ∼105 at 0–40% strain, which was over 900% than NBR-CBH (GF ∼104 at 0–30% strain) and the highest reported so far. This was explained by the breaking of CB networks caused by tight NBR-G structures on straining, leading to high electrical resistance. The NBR-CBH-GL also demonstrated high stability and repeatability in the cyclic loading. In terms of applications, NBR-CBH-GL exhibited high capability for vibration detections and wearable sensing, especially for detection of human bodily motions like speeches, facial deformations, bending, and relaxation of the fingers. [ABSTRACT FROM AUTHOR]

The Shore hardness is still used as a characteristic property for elastomers. Rubber compounds with a hardness of 60 Shore A are often used for vibration insulation elements. The hardness of pneumatic seals lies in the range of 80 Shore A, and for hydraulics it is around 95 Shore A. The hardness of a rubber compound is fine‐tuned by the filler content. With increasing filler content, usually carbon black, the hardness and thus the stiffness of the rubber compound increases. Industrial rubber manufacturers often accept a tolerance within ±3 Shore A. This value practically seems low and is therefore often accepted by the end‐users. The effect of this tolerance on the application properties is investigated on the example of an acrylonitrile‐butadiene rubber compound with a Shore hardness of 60 Shore A and samples with hardness of plus and minus 3 Shore A. Results of tensile tests and dynamic mechanical thermal analysis show that even such small deviation from the nominal value has a significant influence on material stiffness and damping performance over the entire application temperature range. Vibration tests by means of a shaker up to 700 Hz also prove a large variation in vibration transmission behaviour of a vibration de‐coupler due to the rubber compound tolerance. [ABSTRACT FROM AUTHOR]

An attempt has been made to establish a reasonably accurate microkinetics model for accelerated sulfur vulcanization of commonly used acrylonitrile rubber/polyvinyl chloride (NBR/PVC 70/30) blend (NVC73) from a single, isothermal rheograph data of torque versus time. The effect of three different types of fillers, such as pre-exfoliated organically modified montmorillonite (OMMT) clay, graphite (GRT) powder, and high abrasion furnace (HAF) carbon black (CB), were studied. The kinetics study was done with six solid-state reaction kinetics models. Among these, Sestak-Berggren (SB) equation was found to be the best model for the present compositions. The SB kinetic rate expressions were evolved after several iterations using empirical values of autocatalytic and non-autocatalytic orders of ' m' and ' n', respectively. The gum vulcanizate and OMMT clay-loaded compositions were found to have comparable conversion function f (α) and almost identical reaction rate constants at 150°C, under isothermal conditions. In comparison, HAF CB and GRT rate expressions differed from clay-loaded compositions. The validity of the reaction rate equations obtained was confirmed by comparison of plots for experimental and derived conversions with time. [ABSTRACT FROM AUTHOR]

Carbon black (CB) has been used for over one-hundred years as a reinforcing filler in rubber matrix. In order to reduce our dependence on fossil resources, attempts have been made to develop renewable biofillers such as starch in the rubber industry. In this study, NR/SBR blends (50/50) were prepared with different loading of wheat starch (5, 10, 20, 35 and 50 phr). A semi-efficient sulphur vulcanization system (semi-EV) was employed. The curing characteristics of the compounds were determined with a Monsanto Rheometer at 130, 140 and 150 °C. The properties of unfilled and filled NR/SBR blends prepared at 150 °C were evaluated by swelling measurements, tensile tester, dynamic mechanical analyser (DMA) and scanning electron microscope (SEM). The results showed that the optimal cure time, minimum torque, and maximum torque of filled NR/SBR blends were improved. It was found that the tensile strength and the elongation at break of wheat starch filled NR/SBR blends were maximal with the incorporation of 20 phr of wheat starch. The chemical crosslink densities were found to follow the mechanical properties. The results of DMA indicated that incorporation of wheat starch led to an increase in the glass transition temperature whilst reducing the mobility of macromolecular chains of NR/SBR mixtures, and on the other hand improved their slip resistance on wet surfaces, thus indicating its potential application in the manufacture of tyre tread. [ABSTRACT FROM AUTHOR]

We have particularly investigated the correlation law of the effect of different carbon black fillings on the hyper-elastic mechanical behavior of natural rubber by conducting uniaxial tensile tests over a wide range of deformations with different volume fractions of carbon black fillings (0%, 4.7%, 8.9%, 12.8%, 16.4%, 19.7%, 22.7% and 25.2%). The results show that the stress-strain curve for carbon black filled rubber increases with the amount of filling, meaning that the rubber gradually becomes "harder". We explore the correlation between the carbon black filling volume and the parameters of the Yeoh constitutive model by examining the Yeoh constitutive model to characterize the hyper-elastic mechanical behavior of rubber with different carbon black fillings. A quantitative relationship between the material parameters and the carbon black filling volume in the Yeoh constitutive model is presented. A method for calculating the material parameters of the Yeoh constitutive model is developed, and it predicts the correlation between the hyper-elastic properties of rubber and the volume fraction of the carbon black filling. [ABSTRACT FROM AUTHOR]

Conductive carbon black (CCB), carbon nanotubes (CNT) and its hybrids are introduced into the natural rubber (NR) matrix aiming to explore the effect of filler ratio on the transport properties. Solvent transport of NR is found to decrease for hybrid filler systems as compared to single filler incorporated systems. Kinetic parameters of solvent transport behavior of filled NR systems are analyzed using various kinetic models. Upon the computation of kinetic parameters of transport data, it is found that the Peppas-Sahlin model is in good agreement with experimental observations, which suggests that the transport mechanism is diffusion controlled. Rubber-filler interaction parameters are computed and analyzed from the swelling experiments using Kraus, Cunneen-Russel, and Lorenz-Park equations. [ABSTRACT FROM AUTHOR]

Silicone rubber based lightweight composites have been prepared using nano carbon black (CB) as fillers to achieve broadband microwave absorption properties and electromagnetic interference (EMI) shielding over the 8–18 GHz frequency range. The effect of the filler material characteristics on percolation threshold and resultant electromagnetic (EM) properties of composites has been investigated. The composites are prepared by loading different filler fractions (wt. %) of three nano size CB having different characteristics, viz., CB1 (∼5–10 nm), CB2 (∼15–20 nm), and CB3 (∼30–40 nm) in a silicone rubber matrix. The volume resistivity measurements suggest low value of percolation threshold, i.e., 2 wt. % for CB1-rubber composite, 3 wt. % for CB2-rubber composites, as compared to 15 wt. % for CB3-rubber composite. Filler concentration dependent EM properties, i.e., dielectric constant and dielectric loss tangent (tan δe), are evaluated for all the CB-rubber composites. Furthermore, calculated reflection loss (RL) values for these composites indicate that 3 wt. % CB1-rubber, 5 wt. % CB2-rubber, and 18 wt. % CB3-rubber composites can provide more than 90% microwave absorption (RL > −10 dB) in X (8–12 GHz) and Ku (12–18 GHz) bands with thickness ∼2.7 and ∼1.9 mm, respectively. Interestingly, the composites with higher loading (15 wt. %) of CB1 in the rubber matrix are found to give EMI shielding effectiveness values of ∼ 42 dB over the 8–18 GHz frequency range. In conclusion, CB1-silicone rubber composites have been found to give the best performance among the three studied composites. This composite provides >90% microwave absorption over the X band with 2.7 mm thickness and over the Ku band with thickness 1.9 mm with lowest concentration of fillers, i.e., 3 wt. % CB1 in the rubber matrix, and hence found potential for development of lightweight microwave absorbers for stealth applications. [ABSTRACT FROM AUTHOR]

Dynamic behavior in soft matter physics, biology, and nanoscience frequently occurs on submicrosecond timescales. Diffracted x-ray blinking (DXB) is a unique method that can provide a broad range of spatial scale information and is becoming an attractive tool for use at high repetition rate x-ray facilities. In this study, we performed DXB experiments with 890 ns time resolution at the European X-ray Free-Electron Laser Facility to obtain dynamic information about rubber samples that are typically used in automobile tires. Time-resolved scattering was simultaneously recorded for two samples that mainly consisted of carbon black (CB) and polybutadiene (PB). These samples contained either graphitized or non-graphitized CB and displayed significantly different dynamics. A clear interaction between CB and PB was observed, indicating that the mobility of PB was changed by the introduction of CB. Restricted polymer motion was observed in the q-range of 0.78–1.58 Å−1 regions. Our results suggest that the particle network can be flexibly controlled without impairing the mechanical strength of the rubber. [ABSTRACT FROM AUTHOR]

Modelling the flow properties of rubber blends makes it possible to predict their rheological behaviour during the processing and production of rubber-based products. As the nonlinear nature of such complex processes complicates the creation of exact analytical models, it is appropriate to use artificial intelligence tools in this modelling. The present study was implemented to develop a highly efficient artificial neural network model, optimised using a novel training algorithm with fast parallel computing to predict the results of rheological tests of rubber blends performed under different conditions. A series of 120 real dynamic viscosity–time curves, acquired by a rubber process analyser for styrene–butadiene rubber blends with varying carbon black contents vulcanised at different temperatures, were analysed using a Generalised Regression Neural Network. The model was optimised by limiting the fitting error of the training dataset to a pre-specified value of less than 1%. All repeated calculations were made via parallel computing with multiple computer cores, which significantly reduces the total computation time. An excellent agreement between the predicted and measured generalisation data was found, with an error of less than 4.7%, confirming the high generalisation performance of the newly developed model. [ABSTRACT FROM AUTHOR]

The present work aims to study the effect of glycerol as a replacement for mineral oils in natural rubber (NR) composites to obtain suitable properties via cure characteristics, mechanical properties, and thermal stability. Glycerol was used at a 5 phr rate in the compound with carbon black as a reinforcing filler and was compared to mineral processing oils such as aromatic oil, treated distillate aromatic extracted oil, and paraffinic oil. Compared to the other oils, glycerol exhibits better maximum torque and torque differences. Also, a shorter scorch time, cure time, and a higher cure rate index of the compounds were observed. However, although the received mechanical properties, including tensile strength, elongation at break, and compression set of the vulcanized rubber using glycerol showed slightly lower values than the others, the 100% and 300% moduli, as well as the hardness of the composites filled with glycerol, exhibit better values relative to the other commercial oils. These findings demonstrate that glycerol overall presents a good balance of properties, making it beneficial to use glycerol as a substitute for mineral oil in tire, shoe sole, and rubber stopper applications. [ABSTRACT FROM AUTHOR]

The present study is devoted to investigating the mechanical characteristics of a novel natural rubber (NR)-based elastomer nanocomposite reinforced with carbon black and alumina nanoparticles acting as partial and primary reinforcements, respectively. Before conducting various mechanical tests on the specimens, the vulcanization properties of this elastomer nanocomposite was surveyed. It is demonstrated that adding the alumina nanoparticles to the NR-based elastomer matrix can significantly reduce the cure time and improve the quality of the vulcanizates. Then, the influence of alumina nanoparticles on the modulus, tensile strength, elongation at break, and energy absorption capacity of the elastomer nanocomposite were assessed, and the ideal nanoparticles' weight percentage was determined to be 10%. This is supported by calculating the Reinforcing Efficiency Parameter (REP), indicating that the elastomer nanocomposite with 10% alumina has the best reinforcing efficiency in tensile properties. Also, using the Split Hopkinson Pressure Bar (SHPB), it was found that the material is exceptionally strain-rate sensitive, and the specimens exhibited much higher values of stiffness and energy absorption under high strain-rate loading. It is inferred from the results that the elastomer nanocomposite reinforced with the optimal amount of alumina nanoparticles can be an excellent candidate for energy absorption applications under high strain-rate loadings. [ABSTRACT FROM AUTHOR]

Nowadays, waste tires have emerged as one of the most significant sources of environmental pollution. To address this issue, pyrolysis has become a widely adopted method. The continuous rotary kiln reactor has particularly gained popularity in industrial production for pyrolysis due to its suitability. In order to guide the development of new industrial continuous rotary kiln reactors and achieve high-performance pyrolytic carbon black (CBp), this study was conducted to investigate the relationship between the physical and chemical characteristics of CBp and pyrolysis temperature. The elevated-temperature procedure led to a reduction in DBP values from 90 to 70 mL/100 mg, accompanied by a rise in the specific surface area from 63 to 77 m2/g. The augmentation of pyrolysis temperature was noted to induce the agglomeration of CBp particles, thereby negatively impacting their dispersion within polymer matrices. CBp particles at 550 °C exhibited greater structural order, as determined by Raman spectroscopy, which can be attributed to the elevated temperature proximate to the cylinder wall surface. Furthermore, the potential of CBp for reinforcement in natural rubber (NR) was taken into consideration. The pronounced propensity of high-temperature CBps to agglomerate led to uneven dispersion within the polymer, consequently causing heightened heat accumulation and the emergence of the Payne effect. Based on a thorough analysis of the outcomes, the optimal pyrolysis temperature for CBp synthesis within the continuous reactor was ascertained. [ABSTRACT FROM AUTHOR]

A correlation between the steady shear viscosity and complex dynamic viscosity of carbon black (CB) filled rubbers was found by evaluating the Cox-Merz rule and an alternative approach originally proposed by Philippoff for dilute polymer solutions, but since applied to amorphous polymers and concentrated suspensions. This was done by measuring the rheological properties of 16 industrially important rubber mixes containing CB N660 at concentrations of 20 and 35% by volume. A capillary rheometer at various shear rates and a dynamic oscillatory shear rheometer at small and large amplitude oscillatory shear (SAOS and LAOS) were used. The apparent viscosity, storage and loss moduli, complex dynamic viscosity and Fourier transform harmonics were measured. Generally, the shear stress, storage and loss moduli increased with increasing CB loading. Also, the ratio of third and fifth stress harmonics to first harmonics increased with increasing strain amplitude and filler loading. Viscous Lissajous figures (shear stress versus shear rate) at a strain amplitude of 14% showed a nearly linear response for compounds containing CB at 20% by volume. All other shear stress responses demonstrated a strong nonlinearity. The stress waveforms at a strain amplitude of 140% for compounds containing 35% CB by volume displayed a backwards tilted shape expected for highly filled compounds. The stress waveforms at a strain amplitude of 1,000% tended toward a rectangular shape expected for pure polymer. Generally, the nonlinear response of the compounds appeared to be dominated by the filler at strain amplitudes of 14% and 140% and by the rubber matrix at a strain amplitude of 1,000%. The Cox-Merz rule was not applicable for any of the compounds with their complex dynamic viscosity being greater than the apparent viscosity. However, a modification of the approach proposed by Philippoff provided reasonable agreement between the apparent viscosity and complex dynamic viscosity. [ABSTRACT FROM AUTHOR]

The aging of natural rubber (NR) at high temperatures will seriously affect its service lifetime in many key applications. In the present work, the changes in microstructure and mechanical properties of semi-efficient vulcanized NR/carbon black (CB) vulcanizates during thermo-oxidative aging at high temperatures (150–200 °C) and a moderate temperature (95 °C) were compared. At high temperatures, a two-stage aging behavior, which was characteristic of a first rapid decline and then a continuous rise in the crosslinking density (ve), was identified and was found to be closely related to the depletion behavior of antioxidants. The surface cracking behavior observed in the second stage of high-temperature aging was discussed in terms of the grafting reaction of macromolecular radicals on CB particles and thermal expansion. In contrast, the aging of NR at moderate temperatures was much mild, which featured a continuous increase in ve and an oxidation mechanism dominated by peroxy radicals attacking double bonds. In general, the mechanical properties of NR vulcanizates during high-temperature aging depended on the competition effects of structural evolution in the crosslinked network and oxidation-induced chain scission. [ABSTRACT FROM AUTHOR]

The rolling and sliding state of the tread rubber material within contact patch was very important to the handling stability and safety of the vehicle. In this paper, first, the absolute coordinate system was introduced into the digital image correlation method, which improved the ability of the traditional digital image correlation method to solve the large deformation of polymer material surface. Second, a new calculation method of rolling friction coefficient based on the brush model was proposed. Third, a non‐contact full‐field rolling dynamics experimental device was developed to study the effects of carbon black components, rotational speed and vertical load on the rolling mechanical characteristics of tread rubber material. On this basis, the rolling mechanical characteristics of tread rubber material with different formulations were obtained by analyzing the distribution properties of global strain rate, full‐field longitudinal speed and full‐field longitudinal acceleration and the variation laws of transverse/longitudinal strain rate, trajectory of marked points, stress‐strain hysteresis curve and rolling friction coefficient. Finally, the influence mechanism of carbon black composition on rolling mechanical properties of tread rubber material was revealed. [ABSTRACT FROM AUTHOR]

Elastomer composites with low hysteresis are of great importance for sustainable development, as they find application in billions of tires. For these composites, a filler such as silica, able to establish a chemical bond with the elastomer chains, is used, in spite of its technical drawbacks. In this work, a furnace carbon black (CB) functionalized with polar groups was used in replacement of silica, obtaining lower hysteresis. CBN326 was functionalized with 2-(2,5-dimethyl-1H-pyrrol-1-yl)-1,3-propanediol (serinol pyrrole, SP), and samples of CB/SP adducts were prepared with different SP content, ranging from four to seven parts per hundred carbon (phc). The entire process, from the synthesis of SP to the preparation of the CB/SP adduct, was characterized by a yield close to 80%. The functionalization did not alter the bulk structure of CB. Composites were prepared, based on diene rubbers—poly(1,4-cis-isoprene) from Hevea Brasiliensis and poly(1,4-cis-butadiene) in a first study and synthetic poly(1,4-cis-isoprene) in a second study—and were crosslinked with a sulfur-based system. A CB/silica hybrid filler system (30/35 parts) was used and the partial replacement (66% by volume) of silica with CB/SP was performed. The composites with CB/SP exhibited more efficient crosslinking, a lower Payne effect and higher dynamic rigidity, for all the SP content, with the effect of the functionalized CB consistently increasing the amount of SP. Lower hysteresis was obtained for the composites with CB/SP. A CB/SP adduct with approximately 6 phc of SP, used in place of silica, resulted in a reduction in ΔG′/G′ of more than 10% and an increase in E' at 70 °C and in σ300 in tensile measurements of about 35% and 30%, respectively. The results of this work increase the degrees of freedom for preparing elastomer composites with low hysteresis, allowing for the use of either silica or CB as filler, with a potentially great impact on an industrial scale. [ABSTRACT FROM AUTHOR]

This study aims to analyze tire wear particulate matter (TWP) from tread rubber with different formulations and to compare the concentration of TWP with different wear devices. The TWP generated during the abrasion of truck and bus radial (TBR) tires were examined, and the effect of using different types of rubber and carbon black (CB) were investigated. When natural rubber (NR) was solely used as the tire tread rubber material, there was a higher concentration of 5–10 µm TWP. However, when the tread formulation consisted of NR mixed with butadiene rubber, the TWP concentration decreased. Changing the type of CB also reduced the amount of TWP in the 2.5 µm size range. The TWP concentration in the specimens increased with increasing speed and vertical load. The TWP generated during the abrasion tests using wear testers and tire simulators exhibited similar trends. These findings suggest that modifying tire tread formulations can effectively control the distribution and amount of TWP generation. [ABSTRACT FROM AUTHOR]

Pphr rubber with different Carbon percentage is extensively used in engineering applications such as tyres, in which it may be subjected to impact loading leading to high strain rate deformation. This causes large deformations to happen at a variety of strain rates of the material. For this reason, the Babylon industrial company in Iraq suggested a modification of the rubber material used in manufacturing tyres by using different percentages of Carbon black to study the mechanical properties of these materials over a range of loading conditions. Also, the high strain rate and with break strain dependent on their properties provides further reasoning for the research. As for this, the material being irradiated by five percentages of Carbon black makes it vital within the manufacturing process of specific tyres. This work aims to characterise the effects of Carbon percentage on the mechanical properties of pphr rubber. The material was irradiated by five different percentages of Carbon black of pphr rubber dose, Carbon black 30 pphr, Carbon black 40 pphr, Carbon black 50 pphr, Carbon black 60 pphr, and Carbon black 70 pphr. It is a mechanical response, which was studied with the help of uniaxial tensile tests with different strain rates. Previous experimental results are utilised within the Ogden's Model to obtain the parameters for the simulation of the material response using the finite element method (FEM) for comparison purposes. Ogden's Model with first, second, and third-order equations to provide the simulation of the tensile test curves is compared to the experimental curves. Ultimately, it was found that values up to N = 3 produced reasonable results with varying values of pphr and that any value higher only resulted in error within the simulation. [ABSTRACT FROM AUTHOR]