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The elasticity of polymer networks, formed by cross-linking high molecular mass polymers in the melt state and then swollen by a solvent, involves contributions from both the presence of cross-link network junctions and the interchain interactions associated with the combined effect of excluded volume interactions and topological constraints that become modified when the network is swollen. We test the capacity of the previously developed localization model of rubber elasticity, a mean field "tube model," to describe changes in elasticity observed in classical experimental studies of the mechanical properties of this type of network. In order to obtain a satisfactory comparison to the experiments, it was found to be necessary to account for the independently observed tendency of the network junctions to become localized in the network with appreciable swelling, as well as the interchain interactions emphasized in previous discussions of the localization model. [ABSTRACT FROM AUTHOR]

Hydrogen with small molecule size under high pressure can permeate most materials, being a challenge for rubber sealing materials used in hydrogen storage. The volume expansion of rubber materials due to high-pressure hydrogen is an Important indicator of their degradation and failure. Here, both microscopic calculations and experimental investigations of the nitrile rubber were conducted to evaluate the relation between the structure features and the expansion performance. Three factors, the acrylonitrile amount, the chain length, and the crosslinking degree, were considered to impact on the expansion of the nitrile rubber. Current study indicates that the increasing of acrylonitrile amount can result in the reduction of the volume expansion, owing to the preferential interactions between hydrogen and the butadiene group of nitrile rubber. Both of the chain length and the crosslinking degree are positively proportional to the chain elongation and then the volume of the nitrile rubber. Especially, the amount of acrylonitrile was found to be a key factor for evaluating the expansion of nitrile rubber under high-pressure hydrogen. This study performs microscopic calculations and macroscopic experiments to investigate the expansion of nitrile rubber, which is expected to be used in designing the sealing rubber material for high-pressure hydrogen storage applications. Highlights * Acrylonitrile determines the expansion performance of NBR within highpressure hydrogen. * Short chain and low crosslinking density suppressed the expansion of NBR. * Evaluating the expansion of nitrile rubber exposed to high-pressure hydrogen. KEYWORDS high-pressure hydrogen, molecular dynamic calculation, NBR O-rings, volume expansion, 1 | INTRODUCTION Hydrogen as a fuel is a good candidate for meeting the rapidly growing demand for energy in an environmentally friendly way. (1-3) However, the low-volume energy density [...]

In this study, a new concept of the elastic constant ratio was introduced to derive an S-N base function, which has removed the requirement of the shear modulus to be measured in previous work, allowing much wider applications in fatigue prediction with significant reduction in the costs involved in conducting experiments and acceleration of the design process in industries. In this approach, the damage parameter was the effective tensile stress verified for both positive and negative R ratios (the ratio between the minimum stress and the maximum stress). Existing work only provided a general description of the criterion without detailed explicit equations, which does not provide sufficient clarity to the reader and could lead to variable fatigue life predictions. Here, detailed equations are introduced on the calculation procedure to allow accurate results to be obtained for fatigue assessment. The applicability of the approach was validated using two industrial components, that is, the Metacone spring and the bush spring. The maximum values of the damage parameter corresponded to the same failure locations observed in the experiments. The suggested S-N base function, correlated with different materials and failure cycles, could be applied in a fatigue design stage and failure analysis for rubber isolators. Highlights * For the first time, an elastic constant ratio is introduced on different rubbers. * There is no additional test required for the material constants to save cost. * The approach is experimentally validated on two industrial isolators. * Monitoring stiffness in tests cannot determine the crack initiation accurately. KEYWORDS effective tensile stress, failure criteria, rubber fatigue, rubber isolators, S- N base function, 1 | INTRODUCTION Rubber components have been widely applied to dynamic environments in industries with many years of service, such as trains, ships, and automobiles. To meet the durability requirements [...]

To regulate the comprehensive performance of ethylene‐propylene‐diene monomer (EPDM)‐based oil‐absorbing expandable rubber, a series of irradiated α‐olefin‐EPDM7001 rubbers (EOR7001‐X‐Y) are prepared. The influence of the carbon chain length and content of α‐olefins on the structure and properties of the rubber is systematically investigated. Results show that EOR7001‐X‐Y possesses a cross‐linked network structure, and its gel fraction decreases gradually with the increase in carbon chain length and content of α‐olefins. The incorporation of α‐octadecene successfully creates micro‐nanoscale porous structures within the rubber matrix, providing favorable conditions for oil absorption. The introduction of α‐olefins and changes in irradiation dose do not significantly affect the thermal stability of EPDM7001 rubber. The tensile strength slightly reduces, while elongation at break significantly increases, improving the deformation capability. EOR7001‐18‐20 demonstrates exceptional resistance to aging and withstands external forces even after oil absorption. This study supports the development of high‐performance oil‐absorbing expandable rubber. [ABSTRACT FROM AUTHOR]

Bio‐based elastomers and composites are of great interest in numerous applications for environmental sustainability. In this study, bio‐based elastomers with low hysteresis are developed from epoxied soybean oil (ESO) with tetradecanedioic acid (TA) as the curing agent. The as‐prepared ESO/TA thermosets are in the rubbery state at room temperature, with a glass transition temperature (Tg) falling between −19°C and −27°C depending on the amount of TA. With optimized amounts of TA, the elongation at break of ESO/TA thermosets exceeds 130%. ESO/TA thermosets display a stress‐softening behavior and remarkable resilience with low residual strain (<1%) and hysteresis (<7%) after removal of irregular crosslinks and/or interactions by the first stretching. The adhesion of ESO/TA thermosets to wood is also examined through adjustments to the pressure and temperature that are applied for curing. ESO/TA thermosets are then used as the matrix to prepare wood‐polymer composites. Their flexural properties are explored to demonstrate the potential for using ESO/TA thermosets in eco‐friendly wood‐polymer composites. [ABSTRACT FROM AUTHOR]

Through anionic two‐stage polymerization, block‐type styrene‐butadiene rubber (SSBR) with systematically regulable low‐temperature loss peaks is successfully prepared. The influence of 1,2‐Bd unit in the soft segment of block‐type SSBR on mechanical properties, dynamic mechanical properties, and microscopic morphology is studied, while pressure factors are introduced into dynamic mechanical studies. The block‐type SSBR with a soft segment containing 21.9 wt% of 1,2‐Bd exhibits the highest tensile strength, elongation at break, and tear strength. Under atmospheric pressure, the soft segment 1,2‐Bd unit influences the dynamic mechanical properties by altering the chain segment's motion loss capability. As the mass fraction of 1,2‐Bd increases from 21.9 to 58.6 wt%, tanδmax increases, the glass transition temperature of the soft segment increases from −59.0 to −18.9°C. Additionally, influenced by thermodynamic compatibility, the microscopic morphology transitions from strong separation to weak separation. Pressure affects dynamic mechanical properties by altering the free volume of the chain segments. Pressure reduces tanδmax, increases Tg, and raises the average Tg of the soft segment by 11°C. The K value of the linear equation representing the relationship between the soft segment Tg and the mass fraction of 1,2‐Bd is unaffected by pressure. [ABSTRACT FROM AUTHOR]

This study investigates the novel effect of poly(lactic acid) (PLA) optical purity on PLA/liquid natural rubber (LNR) blend films fabricated by solution casting. An investigation was conducted to examine how different levels of PLA optical purity affect the mechanical, structural, morphological, thermal, and barrier properties of PLA/LNR films. Infrared spectroscopy analysis revealed that the D‐isomer content of PLA significantly affected the chemical interactions between the LNR and PLA. The favorable chemical interaction between the LNR and PLA with a high D‐isomer content also increased the elongation at break by 300%. Morphological investigations proved that the chemical interaction also improved the dispersion and reduced the size of the LNR droplets formed in the PLA matrix. Notably, while low D‐isomer PLA blends showed decreased crystallinity (Xc) upon LNR addition, high D‐isomer PLA blends exhibited increased Xc by 460%, leading to a 42% increase in oxygen transmission rate. Additionally, hydrolytic degradation of high D‐isomer PLA increased by 259% with increasing LNR content. Overall, optical purity of PLA plays an important role in determining the properties of PLA blends. [ABSTRACT FROM AUTHOR]

In order to improve the flame retardancy and smoke suppression of silicone rubber foam (SRF), the CoFe‐LDH was fabricated by coprecipitation method and used as flame‐retardant ingredient in SRF. The influence of CoFe‐LDH on the flame retardancy, combustion behavior, and thermal stability of SRF was investigated. The results demonstrate that SRF containing only 1.0 phr CoFe‐LDH can pass V‐0 rating in the vertical combustion test, with a limiting oxygen index of 28.6%. The total heat release and total smoke production are 22.2% and 61.1% lower than that of SRF, respectively. Moreover, CoFe‐LDH can improve the thermal stability of SRF in the high temperature range, and the char residue at 900°C of SRF/LDH composite is obviously higher than that of pure SRF. In addition, to further understand the flame‐retardant mechanism of CoFe‐LDH, the micromorphology of the char residue and the gaseous products during heating for SRF and SRF/LDH composite were analyzed. The results indicate that CoFe‐LDH exhibits excellent flame‐retardant effects in both condensed and gaseous phases for its functions of catalysis, carbonization, and nonflammable gas release. This study provides a more efficient and convenient strategy for the flame retardant and smoke suppression research of SRF. [ABSTRACT FROM AUTHOR]

In this study, a novel biodegradable polymer electrolyte membrane with reduced fuel crossover, high selectivity, and high conductivity compared with Nafion 117 membrane in direct ethanol fuel cells (DEFCs) has been reported. Herein, polyvinyl alcohol/epoxidized natural rubber (PVA/ENR) blend membranes were synthesized via a simple solution casting method and applied in DEFCs. The structural and physicochemical features of the PVA/ENR blend membranes were examined using FESEM, FTIR, XRD, water absorption, ethanol uptake, swelling ratio and oxidative stability. ENR enhances the chemical, structural, and mechanical characteristics of PVA, making it a valuable material in fuel cell applications. The incorporation of ENR into the PVA matrix results in a compact morphology, excessive multifunctional groups, low fuel crossover, and high selectivity. The optimum membrane thickness achieves the highest selectivity, reaching up to 12.32 × 104 S s cm−3 at 30°C. Additionally, the maximum power density achieved is 19.52 mW cm−2, surpassing that of the Nafion membrane, which is only 14.55 mW cm−2 at 90°C. Furthermore, this biodegradable membrane can sustain operation for 1000 h at 90°C, owing to its ability to maintain hydration for an extended period. This study represents the first attempt to combine PVA and ENR in fuel cells. [ABSTRACT FROM AUTHOR]

This article aims to evaluate and compare two types of organic surface-modified-nanoclay of octadecylamine-modified-bentonite-nanoclay (ODA-BNC) and aminopropyltrimethoxysilane-octadecylamine-modified-nanomontmorillonite (APS-ODA-MMT). Each type of nanoclay is combined with silica as a bi-filler for natural rubber (NR)/ethylene propylene diene monomer rubber (EPDM) in a 50/50 blend ratio for possible vulcanized rubber nanocomposite application. The total filler content is 50 phr while nanoclay filler content ranges from 0 to 20 phr, keeping the other ingredients ratio fixed. The prepared composites are characterized by the Fourier transform infrared spectrophotometer (FTIR) and their mechanical and thermal properties are thoroughly investigated. The data reveal that the fillers added to the rubber can improve its surface properties according to their type and amount as confirmed by the Atomic force microscope (AFM), and Scanning electron microscope (SEM) investigation. The surface of rubber containing APS-ODA-MMT displayed higher height (251) and roughness surface (94.11), than those (69.8) and (45.62) respectively, containing ODA-BNC. Moreover, the acid resistance of the prepared composites is verified and indicated that increasing the nanoclay ratio (20%) enhances the acid resistance by reducing the surface distortion while keeping the surface morphology. The mechanical properties and Thermogravimetric Analysis (TGA) measurements showed that the rubber containing ODA-BNC has higher values of stress (2.2), elongation (975), and thermal stability (470, 505, 520°C) than those (1.75), (650), and (440, 460, 470°C) respectively, containing the APS-ODA-MMT. Moreover, the durability investigation of the vulcanized rubber via the AFM found the modified composites can be used in harsh environments as a covering layer in petrochemical networks or chemical factories. [ABSTRACT FROM AUTHOR]

Microplastic particles are emerging water-laden waste that cause a worrying concern towards the environment and humans health. Due to its small size and geometry, and uncertain surface properties, the microplastic waste capturing method in water is still evolving. To date, a number of findings report on the emergence of microplastic surface charging, especially when exposed to water environment. In this study, the natural rubber (NR) latex band was utilized to capture the microplastic waste via a surface capturing mechanism. The NR band was produced using a film casting and curing methods. The surface charging mechanism on the NR band was introduced via the usage of high amount of ZDEC accelerator and, periodic stretching and relaxation procedures. In this work, ZDEC was used as an accelerator for the rubber formulation, and surface charge booster for the NR band. The surface charge of the NR band generates electrostatic interaction with the microplastic waste in water. The polypropylene (PP) microplastic was captured via the surface attraction mechanism using the manufactured NR band. Based on FTIR analysis, the presence of PP microplastic can be quantified on the contaminated NR band surface. The NR band shows the improvement in tensile and tear properties and crosslink density, mainly due to high amount of ZDEC used. At ZDEC loading of 20 phr, the NR band recorded the highest surface potential value, and this is owing to the formation of Zn2+ complex ions on its surface. XRF analysis indicates that the increment of Zn content in the NR band with increasing ZDEC content, that suggests the formation of Zn2+ complex ions. [ABSTRACT FROM AUTHOR]

Elastomers have diverse properties that make them suitable for use in many industrial applications. Natural Rubber, in particular, is an attractive elastomer due to its desirable mechanical properties as well as lightweight compared to metals. However, due to the natural rubber structure, these elastomers are susceptible to heat, oxidation, and chemical compounds, which limits their potential use. In this paper, in order to study the behavior of natural rubber under thermo-oxidative aging, experiments, including continuous stress relaxation, creep, and intermittent tensile tests, are carried out on the samples. Based on the experimental results and using dynamic-network model, a mechanical-chemical-diffusion model is proposed to predict the changes in natural rubber properties during thermo-oxidative aging considering the effect of the natural rubber curing system. In the chemical part of the model, the two main process of aging, including chain scission and crosslinking, are modeled by using two internal variables. The proposed model is implemented using the finite element method to simulate experimental tests for the model verification. The comparisons demonstrate the proposed model ability to accurately simulate the various loading states under thermo-oxidative aging of natural rubber. [ABSTRACT FROM AUTHOR]

The rubber joints mounted on swing arms provide the main part of the yaw stiffness for wheelsets and thus have a significant influence on the dynamic behaviour of railway vehicles. However, their nonlinear dynamic properties concerning the frequency, amplitude, and temperature were not fully considered in previous studies, most of which adopt simple models such as the Kelvin–Voigt model to represent rubber components. This study aims to investigate the radial nonlinear properties of swing arm rubber joints under various conditions and assess their effects on the dynamic performance of high-speed trains. A nonlinear rubber spring model which combines the fractional derivative Zener model with Berg's friction model is established. To achieve a better fit to the measurements of a swing arm rubber joint, an optimisation-based method is employed to identify the model parameters. The viscous and frictional effects of the rubber joint are compared at different frequencies, amplitudes, and temperatures, by determining the predominant element of the nonlinear model. Additionally, the nonlinear rubber spring model is integrated into a high-speed vehicle dynamic model to investigate the effects of the nonlinear properties of swing arm rubber joints on the vehicle dynamic behaviour through the MATLAB/SIMPACK co-simulation method. [ABSTRACT FROM AUTHOR]

This paper analyzes whether the rubber stack traction structure can be applied to 140 km/h metro vehicles from the perspective of vehicle dynamics. The rolling vibration test results indicate that the vehicle Ride Index exceeds the standard limit, the low-frequency vibration of the car body is significantly greater than that of the frame and axle box, and the lateral motion mode of the car body reaches 2.0 Hz. Through the stiffness test, it is found that when the displacement is less than 5.93 mm, the additional stiffness of the rubber stack traction structure exceeds 0.55 MN/m, which is far greater than the stiffness exhibited by the Z-shaped traction rod at the same displacement. The simulation results demonstrate that the excessive additional stiffness of the traction rubber stack is the primary factor for the car body abnormal vibration and does not effectively improve the vehicle stability. It is recommended that this type of metro shall use a rubber stack traction structure with small additional stiffness or Z-shaped traction rod to improve the car body vibration characteristics at 140 km/h. Furthermore, the recommended maximum operating speed for the bogie with the studied rubber stack traction structure is 80 km/h. [ABSTRACT FROM AUTHOR]

Elastomeric products in service condition undergoe thermo-oxidative degradation under the influence of temperature, oxygen, ozone etc. Tyre is one such product where ageing phenomena affect its performance properties as it is subjected to various temperature and environmental conditions during its service life. However, ageing is a complex process and depends on many factors that include rubber type, temperature, stress level, etc. To study the underlying mechanism and kinetics of such intriguing phenomenon, a Natural Rubber based compound was chosen in the present work. The rubber compound was subjected to an aerobic ageing at a fixed temperature of 70 °C and the effect of prolonged ageing time (1 week, 2 weeks, 4 weeks, and 8 weeks) on key performance properties such as, mechanical, dynamic mechanical and fatigue crack growth resistance was evaluated. Fatigue crack growth (FCG) studies were conducted to understand the degradation of crack growth resistance with respect to ageing. The morphology of the fractured surface was also captured by Field Emission Scanning Electron Microscope to reveal the nature of fracture failure. The static as well as dynamic modulus of aged compound was found to be significantly increased with increase in ageing time which was an indication of enhanced cross-linking density. This enhanced stiffness leads to deterioration of the fatigue resistance property and as a result FCG rate increased with ageing time. The samples were characterized by Fourier transform infrared spectroscopy to understand the changes in chemical structure during ageing which revealed that intensity of double bond content was reduced by increasing ageing time. Apparent cross-linking density and other relevant chemical analysis were also performed to establish the proposed mechanism. [ABSTRACT FROM AUTHOR]

Particle shape and grain-scale deformability play key roles in controlling the response of granular material; however, in the literature, the effects of these parameters have generally been evaluated separately. In this context, this study attempts to investigate the coupled effects of these parameters on the repose angle of the sand–rubber mixture using the discrete-element method. For this purpose, the realistic shapes of three different sands and two different rubbers were reflected in the simulations. The grain-scale deformability of rubber particles was modeled by connecting the ball-cluster structure with the linear parallel bond contact model. In addition, to clearly distinguish the role of deformability in the response, the rubber particles were simulated also using a rigid clump model. The parameters of the model were validated using different tests for grain and sample scales. A series of numerical analyses were conducted, and repose angles were determined using image processing techniques. The variation of repose angle was correlated with porosity in the sample scale. The contribution of interparticle friction and interlocking mechanism on the repose angle was revealed using the coordination number and anisotropy coefficient of the contacts in the microscale. The results show that the angle of repose increases with increasing irregularity of the particles. Even though the interlocking mechanism is weakened by the addition of soft rubber, there is an increase in the repose angle of the mixtures thanks to the superior interparticle friction properties of the rubber particles. The results indicate that a high repose angle can be constituted by controlling the particle shape and deformability parameters. [ABSTRACT FROM AUTHOR]

Epoxidized natural rubber with 50 mol% epoxide (ENR-50) was compounded with zinc chloride (ZnCl2) and subjected to torque response analysis using a moving die rheometer. It was found that different ZnCl2 concentrations (3, 5, 7, 9, and 12 millimoles (mmol)) mixed in ENR-50 exhibited positive torque responses, prompting further molecular characterization using Fourier transform infrared spectroscopy. The results indicated distinct absorption peaks at wavenumbers of 442 and 809 cm-1, which signify the presence of -O-Zn-O-coordination linkages. The curing characteristics of ENR and ZnCl2 compounds showed that increasing ZnCl2 content resulted in higher minimum and maximum torque values, but also led to a decrease in scorch time and cure rate index (CRI). Moreover, higher ZnCl2 concentrations enhanced the strength properties (tensile strength, moduli, stiffness, toughness, and hardness), crosslink densities, dynamic shear moduli, initial modulus during relaxation experiments, and thermal resistance, as evidenced by temperature scanning stress relaxation (TSSR), thermogravimetric analysis, and dynamic mechanical analysis. However, an increase in ZnCl2 content led to a reduction in elongation at break due to the higher crosslink density within the coordination networks in the ENR matrix, which resulted in the movement constraint of the rubber vulcanizate. [ABSTRACT FROM AUTHOR]

Natural rubber (NR) composites reinforced with sepiolite and crosslinked with phenolic resin were prepared. Effects of compatibilizer types and contents, namely 3-aminopropyl triethoxysilane (APTES) or epoxidized NR (ENR50), on curing, tensile, strain-induced crystallization, and stress relaxation were investigated. Compared to APTES, ENR50 provided a greater compatibilizing effect in the NR composites. The ENR50 introduced strong physical and chemical interactions between sepiolite and NR, while only physical interaction was present in the APTES compatibilized composites. Stronger interaction between rubber and sepiolite improved filler dispersion, swelling resistance, and tensile strength; and delayed stress relaxation of the composite. Increased addition of ENR50 improved the modulus and tensile strength, and the greatest tensile strength was achieved at 2 phr ENR50 with a 15% improvement over composite without compatibilizer. In the case of APTES, 2 phr level enhanced tensile strength, but a further increase in APTES content degraded tensile, swelling resistance, and stress relaxation responses, due to its plasticizing effect. Moreover, ENR50 enhanced the strain-induced crystallization and delayed stress relaxation of the composites more than APTES. Weaker interaction between rubber and filler in APTES filled composites was due to having only hydrogen bonds formed between rubber and filler, in addition to crosslinks. [ABSTRACT FROM AUTHOR]

Research into sustainable packaging materials has gained increasing importance due to the pressing environmental concerns related to plastic waste. The present study focused on developing a sustainable paper coating based on modified natural rubber (NR) latex filled with gelatin (GT). The graft copolymer latex of NR and poly(vinylbenzyl chloride) bearing quaternary ammonium groups, abbreviated as NR-g-QPVBC, was first synthesized. GT was then incorporated into the latex, and the combination of these materials resulted in a heat-sealable film with good tensile properties and a water barrier. The ionic crosslinking of the latex film was achieved by the reaction with ethylenediaminetetraacetic acid (EDTA). Heat-sealing studies of the NR-g-QPVBC latex film filled with GT (NR-g-QPVBC/GT) revealed its heat-sealability at 160 °C. Scanning electron microscope (SEM) analysis further confirmed the diffusion of the chains across the interface during heat sealing. Dip coating was a method for depositing latex film on kraft paper. The paper coated with the NR-g-QPVBC/GT latex showed a significant increase in dry and wet-tensile strength compared to the uncoated paper. The sealing process was optimized to achieve a heat-seal strength of 755.31 N/m at a dwell time of 3 s and a temperature of 160 °C. The research's practical application was demonstrated by transforming the coated paper into various heat-sealable bags using a handheld bag sealer. [ABSTRACT FROM AUTHOR]

Accelerated degradation tests (ADTs) have been widely adopted for products whose failure is defined as the first-passage-time (FPT) when the degradation path crosses a given threshold. However, for products whose failure is defined as the last-exit-time (LET), few studies related to ADT have been investigated. In this paper, we focus on designing an optimum test condition setting and sample allocation scheme for ADTs under the LET failure mode. In particular, the widely adopted Wiener process model and the generalized exponential acceleration model are used to describe the fluctuating degradation behaviors of products. By minimizing the asymptotic variance of mean-time-to-failure under the normal use condition, we design a two-level optimum test plan and a three-level compromise plan under the constraints of total sample size and stress region. The optimum plans are given in analytical forms, and we prove that the optimum plans under the FPT failure mode and LET failure mode are equivalent under some situations. Finally, a renewed selection method for the upper limit of the stress level in ADTs is proposed based on the prior ADT information from the perspective of accelerated mechanism equivalence. The proposed method is illustrated using a real-world application to rubber rings. [ABSTRACT FROM AUTHOR]

To address the environmental impact of greenhouse gases in cement production, incorporating cement substitute materials is crucial. However, the slow degradation of discarded tires poses environmental challenges, making burial or incineration unsustainable. This study explores the integration of discarded tires as crumb rubber in concrete and the use of silica fume as a cement substitute. Experimental methods, coupled with neurofuzzy systems, were employed to predict the mechanical properties of the resulting modified concretes. In the experimental approach, silica fume replaced cement at weight percentages of 0%, 10%, 12%, and 15%, while crumb rubber substituted sand at volume percentages of 0%, 10%, and 25%. Compressive and flexural strengths were evaluated at seven, 28, and 90 days, with tensile strength assessed at 28 days. The neurofuzzy system utilized six inputs—cement, gravel, sand, silica fume, water–cement ratio, and sample age—to forecast tensile and compressive strength in silica fume-containing concrete. Similarly, six inputs—cement, gravel, sand, crumb rubber, water–cement ratio, and sample age—were used to predict flexural and compressive strength in rubber-containing concrete. The findings reveal that the inclusion of silica fume enhances the mechanical properties of concrete, while the introduction of crumb rubber diminishes these properties. Specifically, a quantitative analysis demonstrates the positive impact of silica fume on the strength and contrasting effect of crumb rubber. The neurofuzzy system exhibits remarkable accuracy in predicting tensile and compressive strength for silica fume-containing concrete and flexural and compressive strength for rubber-containing concrete. [ABSTRACT FROM AUTHOR]

The attenuation of impact inducer vibration is critical to the safety of underground protection structure, equipment and personnel. Metamaterials and metastructures show great potential in terms of sound and impact attenuation. To effectively attenuate ground shock-induced vibration of underground protective structures, scaled shallow-buried annular metastructures with concrete–rubber layered structures were proposed and constructed. Underground explosion experiments were performed to investigate the vibration attenuation effect of annular metastructures with different layered structures. It is clear in this research only annular metastructures with concrete–rubber–concrete structures like annular metastructure model B6 have the most excellent wave attenuation performances, whose rubber layer thickness must be over 6 mm and hardness is 20 HA. Other layered structures with rubber layer thickness of 0.3 cm or with more layers cannot effectively attenuate the shock wave in this research. [ABSTRACT FROM AUTHOR]

This study explores the impact of a graphene oxide (GO)/nano silica (NS) hybrid (GO/NS) filler on the diffusion characteristics of natural rubber (NR) composites when exposed to toluene, xylene, and hexane solvents. The lowest solvent uptake is observed for NR GO/NS 3 (3 phr), which is attributed to forming a robust filler network within the composite. The calculation of crosslink density using the Flory‐Rehner equation reveals significantly higher values for NR GO/NS 3, indicating good crosslinking density in the presence of the hybrid filler. Furthermore, molecular mass between crosslinks (Mc) is calculated, demonstrating a favorable fit with the Affine model. The investigation extends to theoretical modeling, where the Korsemeyer–Peppas and Peppas–Sahlin models are employed to predict solvent uptake behavior. Strikingly, the experimental values exhibit a strong alignment with the Peppas–Sahlin model. This comprehensive analysis provides valuable insights into the diffusion behavior of graphene oxide/nano silica (GO/NS) hybrid‐reinforced natural rubber latex in organic solvents, highlighting potential applications in areas such as solvent‐resistant coatings, barrier materials for chemical storage, and enhanced performance in protective gloves and seals used in harsh chemical environments. [ABSTRACT FROM AUTHOR]

Translation abstract Investigating natural rubber latex (NRL) composites through compressive testing for renewable and sustainable building materialsThis article explores the innovative use of natural rubber latex (NRL) as a fundamental component in the development of sustainable and renewable composite building materials, particularly focusing on incorporating wood chips as reinforcing particles. The study investigates the compressive mechanical properties of various composite formulations, analysing the influence of NRL contents and particle types – considering different wood species, shapes and sizes. Key factors such as particle geometry, NRL content, and sample preparation methods are identified as crucial factors in enhancing the mechanical properties of these composites. The results show that NRL composites exhibit distinctive characteristics like non‐linear behaviour, hysteresis, stress relaxation, and the Mullins effect during compression tests. The significance of these composite materials in construction is heightened by their potential to utilize NRL sourced from plants other than rubber trees, such as dandelions, thus advancing sustainable construction practices. This research aims to focus attention on exploring new, flexible, and highly customized composite materials by utilizing natural fibres and NRL across a range of construction applications. [ABSTRACT FROM AUTHOR]

ABSTRACT This study systematically investigates the small‐strain stiffness of sand‐rubber mixtures, focusing on combined particle disparity—both larger sand with smaller rubber and smaller sand with larger rubber—using the discrete element method. The effectiveness of various state variables in capturing stiffness behavior across different rubber contents and size disparities (SDs) is evaluated. Conventional state variables developed for natural sands, such as void ratio and mechanical void ratio were found to be less effective in describing the small‐strain stiffness characteristics of sand‐rubber mixtures due to distinct properties of rubber. This study then demonstrates that the stiffness contribution of rubber materials could be negligible, emphasizing that particle property disparity is more significant than SD between sand and rubber materials. Therefore, an adapted state variable, considering only active sand particles, shows improved performance for capturing the correlation between small‐strain stiffness with increasing rubber contents, suggesting its potential utility over conventional variables. Additionally, a refined void ratio, including inactive sand particles but excluding rubber, offers a practical alternative for capturing small‐strain stiffness in experimental and engineering practices, aligning with previous experimental observations. These findings underscore the need for developing more effective state variables that accurately reflect the interactions within heterogeneous materials like sand‐rubber mixtures. [ABSTRACT FROM AUTHOR]

Frost-resistant rubbers retain their highly elastic properties over a wide temperature range. They are used in various friction units (e.g., seals), but their high friction coefficient and low wear resistance lead to the need for frequent replacement. In this paper, we propose applying thin (several hundred microns) UHMWPE coatings to formed rubber rings. The application technology depends on the required coating thickness. Friction tests of the coatings and pure UHMWPE were performed using the ball-on-disk (unidirectional sliding) scheme for various loads and velocities. In the experiments, the friction coefficients and temperatures near the contact area were determined. Friction tracks were studied using microscopy methods. The sliding contact of the ball and the two-layer material was modeled to obtain the dependences of the deformation component of friction on the sliding velocity for coatings of different thicknesses. UHMWPE is sensitive to frictional heating, so the thermal problem of determining the temperature in the contact area was also solved. It is shown that the minimum friction coefficient occurs for coatings with a thickness of 600 μm. At the same time, in the case of the 300 μm coating, the surface of the friction track is practically no different from the initial one. Thus, the studied combination of polymers provides antifrictional properties and wear resistance to the surface layer while maintaining the damping properties of rubber. [ABSTRACT FROM AUTHOR]

An investigation was conducted to assess the efficacy of using waste rubber as a substitute for a portion of an aggregate to enhance concrete's sustainability. For the purpose of accomplishing this objective, a total of 12 specimens were constructed and then subjected to a series of tests to investigate their bending behavior. The samples were constructed with the following dimensions: 1000 mm length and a 100 mm by 150 mm cross-sectional area. A few factors were selected, including the impacts of the longitudinal reinforcement ratio and the waste rubber ratio. Based on the volume of aggregates, rubber replacement rates of 0%, 5%, 10%, and 15% were investigated in this study. To assess the beam bending behavior, the stirrup width and spacing were kept constant at ∅6/10. The longitudinal reinforcement was composed of three diameters: ∅6 at the top (for all beams) and ∅8, ∅10, and ∅12 at the bottom. The experimental results demonstrated that the effects of varying amounts of waste rubber and tension reinforcement on the bending and cracking of reinforced concrete beams (RCBs) were varied. The findings indicate that the incorporation of waste rubber into concrete results in a reduction in both the load-carrying capacity and the level of deformation of the material. Additionally, it was shown that as the amount of waste rubber in the RCB increased, the energy absorption capacity and ultimate load decreased. There was a reduction in energy dissipation of 53.71%, 51.69%, and 40.55% for ∅8 when longitudinal reinforcement was applied at 5%, 10%, and 15% replacement, respectively. Additionally, there were reductions of 25.35%, 9.31%, and 58.15% for ∅10, and 38.69%, 57.79%, and 62.44% for ∅12, respectively. [ABSTRACT FROM AUTHOR]

This study focuses on reusing the waste fishing nets with natural rubber (NR) to create a value‐added composite material. WNF fibers at different loadings (2, 4, and 6 phr) and lengths (2, 3, 5, and 7 mm) were investigated for a general tire formulation. The anisotropic nature of WNF was evident in tear strength, with optimal results for 2 mm, 2 phr fiber loading. It displayed 15.87% improvement longitudinally compared with the control. Further, it displayed improved 5.55% hardness, whereas resilience, abrasion volume loss, and tensile strength were decreased. In the second stage, these fibers treated with KOH (2%, 6%, and 10%) with the expectation of enhancing the mechanical properties. The 2% KOH‐treated sample presented a significant escalation in hardness (+12.50%), resilience (+6.25%), abrasion volume loss (+3.63%), tear strength (+17.23%), and tensile strength (+8.20%) as of the control. Partial replacement of carbon black (CB) with 2% KOH treated 2 mm 2 phr WNF was evaluated. A 9% of CB in rubber compound was easily supersede by WNF. Our findings indicated that WNF fibers could be reuse as a filler in rubber composite where special property enhancements are advantageous in tire technology. [ABSTRACT FROM AUTHOR]

Rubber nanocomposites exhibit strain softening under large‐amplitude oscillation shear and large‐strain cyclic tension while the softening behaviors are hard to regulate in industry. Herein, an oligomer deep eutectic solvent (DES) synthesized from polyethyleneglycol and tetrabutylammonium bromide is used to mediate the vulcanization and softening behaviors of natural rubber (NR) gums and their nanocomposites. The results show that DES could accelerate NR vulcanization and improve crosslinking density. For the hydrophilic silica nanocomposites, DES could greatly reduce tanδ and weaken weak strain overshoot accompanying Payne and lower percentages damping accompanying Mullins effects. The effects in nanocomposites filled with hydrophilic/hydrophobic silica and carbon black are investigated and compared. The investigation provides a new way for tailoring elasticity and dissipation of vulcanizate nanocomposites filled with hydrophilic silica. [ABSTRACT FROM AUTHOR]

The quantity of silane chemically bonded to the organoclay's surface significantly influences its dispersion within the polymer matrix, as well as the interfacial interaction. This research presents a groundbreaking method for enhancing the surface properties of montmorillonite (Mt) through the use of γ‐(methacryloxy) propyl trimethoxy silane (KH570) coupled with acid treatment, leading to increased grafting efficiency. Confirmed by FT‐IR, TGA, and XRD, the process effectively bonds organo‐silanes to Mt and achieves a high grafting level of 1.59 mequiv/g. Utilizing a latex compounding method, Mt/rubber nanocomposites are synthesized with thoroughly modified clay for peak performance. Dispersion and interfacial properties are evaluated through XRD, TEM, AFM, and DMTA. The findings reveal that the well‐modified Mt is an exceptional filler, ensuring a high level of dispersion and robust interaction with the rubber matrix. This synergy translates to a marked improvement in the mechanical properties of the composite, with notable enhancements observed in both tensile strength and elongation at break of 9.7 MPa and 1141%, respectively. This innovative approach to the graft modification of clays presents a potent method, offering the potential for the industrial‐scale manufacture of high‐performance clay‐based composites. Highlights: A processing method for preparing high grafting clay with a silane coupling agent.Functionalized clay presents better nano‐dispersion in the polymeric matrix.Strong covalent interfacial interaction is constructed between clay and rubber.Tensile Strength and elongation at break of the composites are obliviously improved. [ABSTRACT FROM AUTHOR]

Given the increasing need for sustainable solutions and the large amount of improperly discarded end‐of‐life tires, recovered carbon black (rCB) from tire pyrolysis was investigated as a filler for rubber composites. This study considered rCB as an alternative to commercial carbon black due to its sustainability and CO2 emissions reduction. Composites with varying rCB contents (0 to 50 per 100 rubber) were produced and assessed for mechanical properties, such as hardness, abrasion resistance, and rheometric tests. The findings were used to train artificial neural networks (ANNs) with MATLAB software to predict rCB contents. Input parameters included optimal curing time, minimum and maximum torque, and results of mechanical tests like Shore A hardness and abrasion loss. The model was trained on data from 90 samples, with 10 reserved for validation. The predicted outcomes closely matched the experimental data, with a maximum prediction error of less than 3%. This indicates that ANNs are effective tools for intelligently modeling the curing process of natural rubber mixtures, minimizing material waste, optimizing production time, and determining suitable carbon black contents for desired mechanical properties. [ABSTRACT FROM AUTHOR]

Rail vehicle air spring bellows consisting of cord rubber composites are subject to a wide variety of stresses. It is therefore crucial to understand the fatigue behavior of such components, as the development process involves the use of empirical methods, which are both time‐consuming and costly. This paper outlines a methodology for assessing the fatigue strength of air spring bellows through representative specimen testing. Ten component tests and a validated numerical model of the air spring bellows are presented. The primary loading scenario investigated in this study is pure pulsating tensile stress with a strain ratio R in the range of 0–0.25. This scenario is considered to be highly damaging, leading to delamination. Comprehensive damage analysis of the specimen is performed using microcomputed tomography. To ensure the transferability of the results, a failure criterion is defined as 20% elongation of the specimen, based on the defined 10% internal pressure drop for the bellow. After statistical evaluation, the transferability of the specimen tests to the component is validated using a local fatigue approach. The correlation coefficient R2 is 0.84, indicating a sound agreement between model and tests with 7 points out of 10 within a scatter factor of 2. [ABSTRACT FROM AUTHOR]

This study investigates the impact of aging in methyl diethanolamine (MDEA) solution on cured rubber compounds comprising ethylene‐propylene‐diene monomer rubber (EPDM), butyl rubber (IIR), and blends, utilizing nano (nZnO) and conventional (ZnO) zinc oxides as curing activators. The analysis reveals that MDEA solution induces degradation in the rubber matrix by grafting amine and amide groups onto the rubber backbone, particularly affecting unsaturated units in diene monomers in EPDM and isoprene units in IIR. The Fourier‐transform infrared (FTIR) analysis validated the addition of these functional groups. Aging contributed to the formation of a thin rubber layer covering carbon black particles, likely due to un‐crosslinking and rubber chain scission, resulting in changes in bound rubber as observed in scanning electron microscopy (SEM) images. Tensile strength and elongation at break typically decreased with aging, with EPDM compounds exhibiting the highest initial tensile strength and IIR compounds demonstrating superior initial elongation. Hardness remains largely unaffected by aging. This study showed the detrimental effects of MDEA exposure on rubber compounds, emphasizing the critical importance of material selection and property tailoring for specific applications in MDEA‐rich environments, such as gas refineries. [ABSTRACT FROM AUTHOR]

The Amazon rubber boom (1850–1930) devastated Indigenous nations that had remained for centuries at the borders of European empires and the nation-states that replaced them in South America. The arrival of the Peruvian rubber company Casa Arana to the Igaraparaná and Caraparaná Rivers in 1899 marked the conquest and colonization of the Murui-Muina nation and their ancestral lands. This essay examines the escape of Murui-Muina clans from Casa Arana and the ethnogenesis of a new kind of Murui-Muina society in the municipality of Leguízamo, in Colombian Amazonia, where they resettled. It argues that although the fleeing clans managed to escape from Casa Arana, the continued contact with rubber tappers, Capuchin missionaries, and Colombian government officials during their flight introduced fundamental changes to Murui-Muina life. However, once settled in Leguízamo, they were able to recreate Murui-Muina life and became the basis of the Indigenous communities that exist today in the municipality. The first two sections follow the fleeing clans along the Putumayo and Caquetá Rivers during the first three decades of the twentieth century; the following section considers their arrival to Leguízamo; and the final section analyzes the ethnogenesis of a new kind of Murui-Muina society in the municipality during the second half of the twentieth century. [ABSTRACT FROM AUTHOR]

Recycling of waste tires is the goal of many studies, where the chemical dissolution method depends on the recovery of tire rubber (TR) and carbon black (CB) from the waste tires. Petroleum ether was used to dissolve tire powder and a black solution was produced which after refluxed at 140°C for two hours with a mixture of adsorbents including silicon dioxide (SiO2) and aluminum oxide (Al2O3) and then filtered, will give clear rubber filtrate and CB precipitate and the used petroleum ether was totally regenerate. The rubber was recovered with a weight percentage of 24% (w/w), whereas CB was reclaimed with 20% (w/w) from the total waste tire used. The recovered rubber was characterized and its functional groups were studied by 1H-NMR and FTIR spectroscopy which shows the rubber is polyisoprene blended with polybutadiene. The XRD, FESEM, and thermal analyses (TGA, DTA, and DSC) show the recovered rubber is amorphous with an elastic nature, thermally stable with endothermic behavior, and contains some inorganic impurities. On the other hand, the BET (Brunauer-Emmett-Teller) analysis, of carbon black shows it is a mesoporous material with a high specific surface area (as = 149.44m² . g -1) and pores with a mean diameter (13.623 nm). The particle size, structure and surface chemistry of the reclaimed CB which was measured accordingly by XRD, BET, and FESEM and it was emphasized that the CB has excellent adsorption qualities. Keywords: Recycling of tires, rubber, petroleum ether, carbon black, Silicon dioxide, Aluminum oxide. [ABSTRACT FROM AUTHOR]

The issue of forming a reliable and sustainable structure of crumb-rubber-modified binder is an important scientific and technical task. The quality of this task will increase the technical and economic efficiencies of road construction materials. This work is dedicated to developing a scientifically justified method of directed thermomechanical devulcanization, which ensures the solubility of the crumb rubber in the complex structure of a polydisperse composite material, preventing the formation of aggregates consisting of unsaturated crumb rubber particles, whose elastic aftereffect causes intensive cracking, especially during low-temperature road operations. The novelty in the first part of this article is due to the fact that, for the first time, the quantitative ratio of the polymer component in the crumb rubber was experimentally determined. The ratio of the polymer component to the total content of the other rubber components in the crumb rubber (CR) was determined to be, on average, 93.3 ± 1.8%. The stabilities of the compositions of crumb rubber from different batches were experimentally studied. The nature of the polymer component in the crumb rubber was determined. A hypothesis was formulated to obtain a thermodynamically stable and sustainable binder modified with crumb rubber. To evaluate the compatibility of hydrocarbon plasticizers with the studied CR samples, the following semi-empirical and thermodynamic compatibility parameters were calculated: Hildebrand solubility parameters based on evaporation energy and surface tension, Barstein's compatibility parameter |X|, Traxler coefficient, and the mass ratio of paraffin naphthene:asphaltenes. It was shown that for the substances under study, it is advisable to justify the choice of plasticizer based on chemical compatibility criteria. It was established that a supramolecular plasticization mechanism occurs in the "hydrocarbon plasticizer–crumb rubber" systems under consideration. In the development of the crumb-rubber-modified binder, it was found that the use of activated crumb rubber (ACR) from large tires does not ensure the achievement of a stable and resilient structure of the crumb-rubber-modified bitumen. [ABSTRACT FROM AUTHOR]

The coherent perceptual experience of one's own body depends on the processing and integration of signals from multiple sensory modalities, including vision, touch, and proprioception. Although nociception provides critical information about damage to the tissues of one's body, little is known about how nociception contributes to own-body perception. A classic experimental approach to investigate the perceptual and neural mechanisms involved in the multisensory experience of one's own body is the rubber hand illusion (RHI). During the RHI, people experience a rubber hand as part of their own body (sense of body ownership) caused by synchronized stroking of the rubber hand in the participant's view and the hidden participant's real hand. We examined whether the RHI can be elicited by visual and "pure" nociceptive stimulation, ie, without tactile costimulation, and if so, whether it follows the basic perceptual rules of the illusion. In 6 separate experiments involving a total of 180 healthy participants, we used a Nd:YAP laser stimulator to specifically target C and Aα fibers in the skin and compared the illusion condition (congruent visuonociceptive stimulation) to control conditions of incongruent visuonociceptive, incongruent visuoproprioceptive, and no nociceptive stimulation. The illusion was quantified through direct (questionnaire) and indirect (proprioceptive drift) behavioral measures. We found that a nociceptive rubber hand illusion (N-RHI) could be elicited and that depended on the spatiotemporal congruence of visuonociceptive signals, consistent with basic principles of multisensory integration. Our results suggest that nociceptive information shapes multisensory bodily awareness and contributes to the sense of body ownership. [ABSTRACT FROM AUTHOR]

The paper reports the study of surface roughness based opto-mechanical properties of Chlorobutyl (CIIR)/Natural Rubber (NR) 70/30 polymers filled with different contents of hybrid (CB/CN) using indigenously designed THz spectrophotometer between 1 and 2.0 THz range. The carbon black (CB) and Carbon nano powders were mixed between 20 and 2.0–7.5 Phr range in the chlorobutyl and natural rubber matrix for improvising their surface quality and mechanical strength. The physical and structural changes were ascertained in terms of transmission, refractive indices and absorption coefficients. The percentage of filler also influences the morphology and surface roughness quality of the rubber due to intercalation and measured in terms of surface roughness factor 'g' optical impedance 'z' and reflection coefficients between 0.1 and 2.0 THz range. The obtained values of optical impedance lie between 220.2 and 235.6 Ω range and were correlated with the mechanical strength of the rubber samples. It provides a new modality to understand the effect of fillers on the strength of rubber samples. [ABSTRACT FROM AUTHOR]

Chemical degradation of PET with natural rubber was carried out. The product obtained was characterized by FTIR, and it was found that the intensity of the vibration signal of the carbonyl group (1719 cm−1) depends on the mass of rubber used in the reaction and not on the PET degradation products, reaching an adequate mass ratio of Rubber/PET = 4. The chemical structure of the product obtained was rubber chains with end groups of ethylene terephthalate oligomers. The pasting properties of the banana starch were modified with the resulting product, affecting its gelatinization process and the maximum viscosity value of 5.78 Pa.s to 1.50 Pa.s at a temperature of 25 °C. Starch degraded PET-rubber films have better mechanical properties than starch-only films. Additionally, these films degrade at lower temperatures (491 to 469 °C) than starch-only films. The ability of these films to conduct electrical current increases up to 25.52% with respect to that of the native starch film. SEM morphology of the starch degraded PET-rubber films shows the formation of clusters, which causes the films to present adhesive characteristics, indicating that these films have a high potential for application in the adhesive and paint industry as biodegradable materials. [ABSTRACT FROM AUTHOR]

The article discusses the use of rubberized concrete in reinforced concrete columns and its performance under axial and cyclic loads. The addition of crumb rubber to the concrete reduces its compressive strength and load capacity but improves its displacement ductility and damping ratio. The study suggests that rubberized concrete can enhance the performance of concrete columns under cyclic loading and delay the onset of earthquake damage. The article provides a technical analysis of various parameters and their implications for the seismic performance of rubberized concrete. [Extracted from the article]

While designing tire performance, understanding the relationship between the tire belt or tread rubber and the road surface is crucial, as represented by the cornering performance and wear characteristics. To survey this relationship, the force generated when a tire moves over a force sensor installed on the drum side of a tire drum tester or a sheet-type sensor installed on the road surface is measured to estimate the contact pressure distribution. The former method does not allow measurements on a flat surface, whereas the latter uses an actual vehicle; thus, obtaining stable data is challenging. In this study, we measured the triaxial forces acting on the tread block of a tire with a slip angle applied to the tire alone and discussed the characteristics of these forces. In the proposed measurement method, a tire tread block is machined, and a small triaxial force sensor is embedded. This method enables measuring the forces between the tire belt and the road surface. Finally, the force generated via the tire/road interaction on the tread block was measured using a flat-belt tester. The characteristics of the forces generated by the tread block are reported based on the obtained results. [ABSTRACT FROM AUTHOR]

A theoretical study was conducted to investigate the cross-sectional configurations and the tensile forces of an air-inflated rubber dam anchored on the sidewall of the rigid base. A series of large-scale model tests were conducted using rubber dam models with a cross-sectional perimeter of 1.0 m and a length of 8.5 m. The results obtained from the analytical solutions agree well with those obtained from model tests. It is found that there is an optimum height of the rubber dam, especially for larger anchor depth with the increase of the inflated air pressure. The smaller the anchoring depth the higher the optimum inflated air pressure. The contact length between the rubber dam and the rigid base gradually decreases with the increasing inflated air pressure. The greater the anchor depth, the faster the contact length decreases to zero. Generally, the tensile force linearly increases with the increase of the normalized air pressure and the decrease of the anchor depth. • Theory was derived to calculate an air-inflated rubber dam anchored on the sidewall of rigid base. • A series of large-scale model tests were conducted to verify accuracy of the theoretical model. • Effects of upstream water levels, inflated air pressures and anchor depths were analyzed. [ABSTRACT FROM AUTHOR]

In polymer materials technology, replacing synthetic stabilizers with natural antioxidants is a current and developing issue. Cloves have antimicrobial and antioxidant properties, which is why they are often used in medicine and in gastronomy. Eugenol – the main component of clove oil, is also a strong antioxidant. The aim of the study was to analyze and compare the anti-aging effects of eugenol and cloves in epoxidized natural rubber (ENR) compositions. The 2,2′-azinobis- (3-ethylbenzothiazoline-6-sulfonate (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and CUPric reducing antioxidant capacity (CUPRAC) tests showed the ability of plant materials to reduce free radicals, as well as iron and copper ions. ENR compositions with additives were characterized by a longer oxidation induction time (OIT). The samples after solar aging showed better resistance to elevated temperature and solar radiation, as evidenced by aging coefficients (K) calculated on the basis of mechanical properties and carbonyl indexes of samples with eugenol and cloves. Cloves and eugenol can be successfully used as natural stabilizers in elastomeric materials. [ABSTRACT FROM AUTHOR]

This study addresses the increasing demand for eco-friendly rubber compounding additives by exploring greensynthesized zinc oxide (ZnO) nanoparticles. The green synthesis of ZnO nanoparticles is gaining attention due to its ecofriendly approach and potential applications. This study investigates the synthesis of ZnO nanoparticles using sweet lime peel extract as a green method, comparing it with chemical synthesis. The obtained nanoparticles are characterized and evaluated for suitability as activators in natural rubber composites for tire applications. Furthermore, the cytotoxicity of the prepared ZnO nanoparticles on mice cells is assessed, revealing lower toxicity for green-synthesized ZnO compared to chemically synthesized ZnO. Payne effect analysis on the composites demonstrates improved polymer-filler interaction and mechanical properties for the green-synthesized ZnO-loaded composites. Notably, the incorporation of green-synthesized ZnO leads to significant enhancements in tensile strength due to its higher surface area. It achieves desirable magic triangle tire properties, including low rolling resistance, high wet traction, and high abrasion resistance. These findings highlight the promising potential of green ZnO as an environmentally friendly alternative to chemical ZnO in rubber compounding. [ABSTRACT FROM AUTHOR]

Background: Though proposed by Lake and Yeoh in 1978 for vulcanized rubber characterization and possessing unique advantages with respect to traditional fracture characterization approaches, the Y-shaped cutting technique has been applied to a limited number of materials. Objective: This limited implementation may be due to researchers' unfamiliarity with the effects of Y-shaped cutting conditions and technique limitations, as well as a lack of standards. This review and best practices guide aims to provide a detailed road-map of the capabilities of Y-shaped cutting, with guidance for designing, executing, and interpreting its results. Method: By performing Y-shaped cutting at a constant blade propagation rate, fracture initiation effects encountered in many 'tearing' tests are bypassed. Meanwhile, unlike other contact-driven fracture conditions (needle insertion or cutting), the 'leg' separation renders the cutting nearly 'frictionless' under a variety of conditions. Results: Y-shaped cutting possesses two unique attributes. Under certain conditions (Zhang and Hutchens in Soft Matter 17(28):6728–6741, 2021), it can yield a fracture energy independent of sample and cutting implement geometry. In contrast to soft solid crack blunting, cutting reduces both the finite stretch and failure process zones to within a field of view readily imaged on a microscope, useful for microstructural studeis. To facilitate access to the above advantages, we summarize experimental variables and their role the fracture response and/or successful cutting and establish a pseudo-standard using silicone. Conclusion: This overview and recommendations empowers researchers to implement this highly-tunable cutting method in order to provide insights into other classes of materials in the future. [ABSTRACT FROM AUTHOR]

The Oomycetes fungus Phytophthora spp. which causes Abnormal leaf fall (ALF) disease poses a significant threat as one of the most devastating diseases affecting rubber trees in India. A total of 30 Phytophthora isolates were obtained from ALF-affected samples collected during the Southwest monsoon season of Kerala. The colony morphology of Phytophthora isolates revealed eight different types of growth patterns, with stellate, stellate striated, and petaloid patterns growing rapidly, whereas chrysanthemum pattern grew slowly. Sporangia were papillate to non-papillate in various shapes, and sporangiophores exhibited simple, simple sympodial, or irregularly branching patterns. Highly virulent isolates exhibited petaloid morphology and rapid growth rates. Regardless of their virulence, all isolates showed susceptibility to the fungicide metalaxyl. Under in vitro conditions, the highly virulent isolate (R17) from rubber caused severe infections in chili, brinjal, and tomato with brown water-soaked lesions. Sequence analysis and multi-locus phylogeny of Internal transcribed spacer (ITS), cCytochrome c oxidase 1 (COX 1), Heat shock protein 90 (HSP 90), and Ribosomal protein L10 (RPL 10) confirmed the pathogen as Phytophthora meadii. A comprehensive understanding of both morphological and molecular traits of P. meadii is crucial for precise identification and future genetic variability studies. • P. meadii isolates exhibited varied morphology and susceptibility to the metalaxyl. • Hevea clones RRII 414 and 417 showed tolerance to P. meadii. • Solanaceae species like brinjal, chili, and tomato are susceptible to cross-infection by P. meadii from rubber trees. • Multi-locus phylogeny with ITS, COX1, HSP90, and RPL 10 genes confirmed the identity of P. meadii. [ABSTRACT FROM AUTHOR]

Waste slag and rubber particles are commonly used to modify concrete, offering benefits such as reduced cement consumption and lower greenhouse gas emissions during cement production. In this study, these two environmentally friendly, sustainable waste materials were proposed for the preparation of mortar intended for snow-melting pavements. A series of experiments were conducted to evaluate the performance of the material and to determine whether its compressive and flexural strengths meet the requirements of pavement specifications. The mortar's suitability for snow-melting pavements was assessed based on its thermal conductivity, impermeability, and freeze–thaw resistance. The results indicate that slag, when used in different volume fractions, can enhance the compressive and flexural strength of the mortar. Slag also provides excellent thermal conductivity, impermeability, and resistance to freeze–thaw cycles, contributing to the overall performance of snow-melting pavements. When the slag content was 20%, the performance was optimal, with the compressive strength and flexural strength reaching 58.5 MPa and 8.1 MPa, respectively. The strength loss rate under freeze–thaw cycles was 8.03%, the thermal conductivity reached 2.2895 W/(m * K), and the impermeability pressure value reached 0.5 MPa. Conversely, the addition of rubber particles was found to decrease the material's mechanical and thermal properties. However, when used in small amounts, rubber particles improved the mortar's impermeability and resistance to freeze–thaw cycles. When the rubber content was 5% by volume, the impermeability pressure value reached 0.5 MPa, which was 166.7% lower than that of ordinary cement mortar. Under freeze–thaw cycles, the strength loss rate of the test block with a rubber content of 25% volume fraction was 9.83% lower than that of ordinary cement mortar. [ABSTRACT FROM AUTHOR]