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Non-linear viscoelastic characteristics of carbon black (CB)-filled fluoroether rubber mixture samples are investigated by large amplitude oscillatory shear (LAOS) tests. Three analysis approaches based on LAOS tests are then used to discuss correlations between rheological behavior and CB-filling amount. Each non-linear viscoelastic parameter of the mixture presents a three-stage characteristic with increasing CB content, which are attributed to the alteration of CB-elastomer network structure, corresponding to the state where gum continuous phase, CB-elastomer mesophase, and excessive CB agglomerates predominate in the mixture compound, respectively. According to the findings in engineering experiments, a CB content of 35-40 phr is recommended, taking into account tensile, hardness, and aging properties. Excessive CB agglomerates are found to reinforce CB-elastomer networks at elevated temperatures. For cold-resistance properties, structural changes in CB-elastomer network are proven to exert little effect on [T.sub.g], but a higher CB content was found to slightly enhance the cold-resistance coefficient, probably due to the decrease in velocity fraction of gum rubber. Highlights * LAOS tests were utilized to study the influences of CB on fluoroelastomer; * Three-stage alteration was observed in the mixture with increasing CB content; * Correlation between CB content and the engineering properties was discussed. KEYWORDS carbon black-elastomer interaction, fluoroether rubber, large amplitude oscillatory shear, non-linear viscoelasticity, 1 | INTRODUCTION Fluoroether rubber is a special type of fluoroelastomer (FKM), in which the polymerization monomers contain a large proportion of perfluoroethers such as perfluoromethyl vinyl ether (PMVE), perfluoropropyl [...]

The calendering process of pole piece is a key step affecting the performance of the power battery. In the calendaring process, rubber roller materials will produce hysteresis heat, resulting in rolling resistance, which will lead to energy loss. The thermo-mechanical coupling model for calendering rubber roller has been established and the effects of materials, calendering speeds, and roller structure shape on the viscoelastic temperature rise of rubber roller were analyzed. Solution-polymerized styrene-butadiene rubber (SSBR) materials with different fillers have the greatest impact on temperature rise, followed by the roller shape, and calendering speed is smaller. The loss modulus of SSBR filled with white carbon black studied was smaller, and the temperature rise at high speed was 14.5[degrees]C higher than that at low speed. The optimized roller shape has a temperature rise of 10.4[degrees]C lower than the original shape. The research results could provide reference for the calendering rubber roller design of pole piece and similar processing. Highlights * A thermo-mechanical coupling model of calendering rubber roller was established. * The rubber roller made of SSBR-VN3 has a lower temperature rise. * Optimized structure reduced contact pressure by 28.1% and temperature rise by 10.4[degrees]C. KEYWORDS battery pole piece calendaring, FEM, hysteresis temperature rise, rubber roller, thermomechanical coupling model, 1 | INTRODUCTION With the increasingly serious problems of environmental pollution and energy shortage, especially with the development of science and technology and the process of modernization, the consumption of [...]

Zinc complexes have a considerable impact on human health and the environment, especially on aquatic wildlife. One of the primary sources of zinc release to the environment is worn rubber particles from tires. The environmental footprint of zinc oxide (ZnO) during production, use, and landfilling has prompted researchers to reduce its use in rubber formulations due to ecological and economic concerns. In this study, composite ZnO materials where ZnO particles are coated on precipitated calcium carbonate (CaCO3) are used in styrene butadiene rubber/butadiene rubber (SBR/BR) compounds, and their performance is compared with white seal ZnO and active ZnO. Trial compounds are prepared on a laboratory scale using composite ZnO materials with ZnO:CaCO3 ratios of 40:60, 60:40, and 90:10, and control compounds with white seal and active ZnO. All compounds are tested to evaluate their curing and physico-mechanical properties. It is observed that the surface area of ZnO plays an essential role in crosslink density and, hence, compound performance. Trial materials have no negative effect on the curing and mechanical properties of the compounds. Thus, it is concluded that composite ZnO materials can be used as alternatives to both white seal ZnO and active ZnO. They have environmental and economic advantages due to their lower ZnO content. The compound recipe has the potential to be used for tire tread compounds.

Extreme rainfall impacts rubber production, reducing effective tapping days and cumulative annual output and having awide-ranging effect on rubber crop cultivation. This study aimed to find out how rainfall and rainy days affected the rubberproduction of the Kusen clone in Muara Enim Regency’s Rambang District. The study was conducted on a rubber plantationof Kusen clone, which has an area of 1 ha. The initial stage in analyzing the impact of climate change on Kusen clone rubberproduction in Rambang District, Muara Enim Regency, was identifying the independent and dependent variables. The T-testwas conducted to see whether each independent variable partially has a significant effect on the dependent variable. Rubberproduction has fallen year after year, with an average of 205.12 kg/ha in 2019 during the first year of tapping and 118.43in 2023. The coefficient value (r) shows a 27.2% (sufficient correlation) magnitude association between the rainfall andrainy-day variables and the rubber productivity variable of the Kusen clone. In Correlation test results, rainfall and rainydays are strongly associated with producing Kusen clone rubber, as demonstrated by the correlation analysis value of 0.846.Regression research showed that rainfall and rainy days had a statistically insignificant effect on rubber production on therubber clone Kusen in Rambang District, Muara Enim Regency.

The recent focus on enhancing sustainability has emphasized the proper utilization of natural fibers and waste materials. Natural fiber reinforced composites have emerged as a promising solution for future bio-based products. This study aims to investigate the synergistic effects between date palm fiber (DPF) and Nitrile Butadiene Rubber (NBR) in order to develop innovative bio-based composites suitable for diverse industrial applications. The composites were produced through a mixing process using a Brabender internal mixer, followed by rolling. Various reinforcement materials and processing conditions were employed to characterize and analyze the mechanical properties of the composites. These properties included tensile strength, tensile modulus, strain, tear resistance, mechanical hardness, and compression behavior, assessed according to ASTM standards. The results revealed that the composites with a 40 wt% fiber loading exhibited the highest elastic modulus and tear resistance, indicating good compatibility and adhesion between the fibers and rubber. Additionally, the composites displayed increased brittleness and strain with higher fiber content. The mechanical hardness of the composites suggested their potential for various industrial applications, with the best results obtained at a 30 wt% fiber loading. Furthermore, the compression strength of the composites, evaluated using the ASTM D395 standard and a compression molding method, displayed significant improvement at a 40 wt% fiber content, indicating favorable characteristics and potential for industrial applications requiring oil, fuel, abrasion, and heat resistance in the form of bio-based products.

We study the friction when rectangular blocks made from rubber, polyethylene, and silica glass are sliding on ice surfaces at different temperatures ranging from −40 to 0 °C, and sliding speeds ranging from 3 μm/s to 1 cm s−1. We consider a winter tire rubber compound both in the form of a compact block and as a foam with ∼ 10 % void volume. We find that both rubber compounds exhibit a similar friction on ice for all studied temperatures. As in a previous study at low temperatures and low sliding speeds, we propose that an important contribution to the friction force is due to slip between the ice surface and ice fragments attached to the rubber surface. At temperatures around 0 °C (or for high enough sliding speeds), a thin pre-melted water film will occur at the rubber–ice interface, and the contribution to the friction from shearing the area of real contact is small. In this case, the dominant contribution to the friction force is due to viscoelastic deformations of the rubber by the ice asperities. The sliding friction for polyethylene (PE) and silica glass (SG) blocks on ice differs strongly from that of rubber. The friction coefficient for PE is ∼ 0.04 − 0.15 and is relatively weakly velocity dependent except close to the ice melting temperature where the friction coefficient increases toward low sliding speeds. Silica glass exhibits a similarly low friction as PE for T > −10 °C but very large friction coefficients (of order unity) at low temperatures. For both PE and SG, unless the ice track is very smooth, the friction force depends on the position x along the sliding track. This is due to bumps on the ice surface, which are sheared off by the elastically stiff PE and SG blocks, resulting in a plowing-type of contribution to the friction force. This results in friction coefficients, which locally can be very large ∼ 1 , and visual inspection of the ice surface after the sliding acts show ice wear particles (white powder) in regions where ice bumps occur. Similar effects can be expected for rubber blocks below the rubber glass transition temperature, and the rubber is in the (elastically stiff) glassy state. [ABSTRACT FROM AUTHOR]

• MAA introduces unsaturated carboxylate metal salt bonds on the steel slag surface. • MAA etching of steel slag to make it loose and porous. • Steel slag can shorten the vulcanization molding cycle. • The performance of MAA-in-situ-m-SS filled natural rubber was significantly improved. • MAA-in-situ-m-SS can partially replace carbon black as a rubber filler. As a by-product of the steelmaking industry, the large-volume production and accumulation of steel converter slag cause environmental issues such as land occupation and dust pollution. Since metal salts of unsaturated carboxylic acid can be used to reinforce rubber, this study explores the innovative application of in-situ modified steel slag, mainly comprising metal oxides, with methacrylic acid (MAA) as a rubber filler partially replacing carbon black. By etching the surface of steel slag particles with MAA, their surface roughness was increased, and the chemical bonding of metal methacrylate salt was introduced to enhance their interaction with the molecular chain of natural rubber (NR). The results showed that using the steel slag filler effectively shortened the vulcanization molding cycle of NR composites. The MAA in-situ modification effectively improved the interaction between steel slag and NR molecular chains. Meanwhile, the physical and mechanical properties, fatigue properties, and dynamic mechanical properties of the experimental group with MAA in-situ modified steel slag (MAA-in-situ-m-SS) were significantly enhanced compared with those of NR composites partially filled with unmodified slag. With the dosage of 7.5 phr or 10 phr, the above properties matched or even exceeded those of NR composites purely filled with carbon black. More importantly, partially replacing carbon black with modified steel slag reduced fossil fuel consumption and greenhouse gas emission from carbon black production. This study pioneered an effective path for the resourceful utilization of steel slag and the green development of the steelmaking and rubber industries. [ABSTRACT FROM AUTHOR]

Millions of used or worn-out tyres are disposed of by many countries annually. These tyres can be put to good use when recycled. Used tyres are among the most problematic and challenging sources of solid waste, especially in landfills. Therefore, the use of waste tyres for composite materials having desired performance properties can be used as a means of disposing of the tyres. Fibrous material-reinforced composites with enhanced physical and mechanical performance and incorporating sisal fibres were produced using waste tyre material, sisal, and polyester resin. The physical and mechanical properties of hybrid composite board panels, including flexural strength, compression strength, tensile strength, and water absorption, were determined according to ASTM Standards. The rubber tyre particles used in the study had a size of 1.00 mm, and the sisal used had an average length of 6mm. A systematic experimental design was formulated and worked accordingly in the fabrication of the composite. The hybrid composite produced has adequate mechanical properties to perform as a substitute for solid wood in several applications such as tabletops, general purpose, load-bearing boards, ceiling boards, furniture, door panels and partitioning boards. [ABSTRACT FROM AUTHOR]

The compressive strength (CS) of crumb rubber concrete (CRC) can be improved through a chemical pretreatment involving immersion of the crumb rubber particles in a NaOH solution. Despite the potential benefits of this treatment, accurately estimating the CS value of NaOH-pretreated CRC remains challenging. To address this issue, a comprehensive database encompassing 118 entries on the fundamental mixtures of CRC along with NaOH concentration and pretreatment duration has been meticulously compiled for machine learning analysis. The random forest (RF) algorithm is employed to predict the 28-day CS value of NaOH-pretreated CRC. The model hyperparameters are optimized using a random search technique with 10-fold cross-validation. The findings reveal that the optimized RF attains acceptable predictive performance, yielding RMSE, MAE, and R2 values of 3.83 MPa, 2.84 MPa, and 0.85, respectively, on the testing dataset. Additionally, the model is interpreted using multiple techniques, including permutation importance, RF model-based feature importance, and Shapley additive explanation from global or local perspectives. The feature importance analyses consistently highlight the crucial role of crumb rubber content in determining the 28-day CS value of NaOH-pretreated CRC, and the influence of NaOH concentration and pretreatment time appear relatively inconsequential compared to features associated with the CRC mixture. This research contributes to a deeper understanding and better mixture design of CS for NaOH-pretreated CRC. [ABSTRACT FROM AUTHOR]

The emerging self-healing concept in rubber materials appears to be a good option for reducing rubber waste since it can enhance the longevity of the product's structure in conjunction with standard development goals to ensure sustainable consumption and efficient use of resources. Self-healing elastomers are fabricated to heal cracks and damage both at the micro and macroscopic levels to restrict failure by incorporating healing agents extrinsically or intrinsically. The major successful techniques to fabricate self-healing rubber were reviewed. The review also focuses on testing and analysis methods to understand the healing phenomena and quantification methods to measure the healing performance. The review also includes an overview of the self-healing elastomers for tyre applications. [ABSTRACT FROM AUTHOR]

The aim of this study is to explore a method for modifying waste brick powder (WBP) in order to reapply it to rubber products for effective resource recycling. Firstly, we use the auto polymerization of catechol/polyamine (CPA) on the surface of WBP to form a poly catechol/polyamine (PCPA) coating as an intermediate reaction platform. And then the macromolecular modifier, epoxy-functionalized elastomer (ethylene vinyl acetate-glycidyl methacrylate terpolymer) (EVMG), is further grafted onto the PCPA coating to prepare the WBP@EVMG hybrid materials. During the preparation of the WBP@EVMG hybrid materials, a ring-opening reaction between the amine group of PCPA and the epoxy group of EVMG occurs. The NR/WBP@EVMG composites are prepared by mechanical blending. The interfacial interactions between WBP@EVMG and NR are analyzed and verified in detail by dynamic mechanical analysis (DMA) and rubber process analyzer (RPA). It is shown that the modified NR/WBP composites show increased vulcanization rate and better mechanical properties, and the tensile strength, abrasion resistance, cracking strength, and wet slip resistance of NR/WBP@EVMG-15 are increased by 29%, 6%, 16%, and 11%, respectively, compared with that of NR/WBP composites, which provides a unique idea for the reuse of waste brick powder in rubber. [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]

Acrylonitrile-butadiene-styrene (ABS) resin is a typical elastomer-toughening plastic, where the rubber component is polybutadiene (PB). In this paper, the influence of PB-g-Styrene-Acrylonitrile (SAN) concentration on the mechanical properties as well as the flow behavior of the ABS resin was studied. The notched impact strength of the ABS resin including 30 wt% PB-g-SAN was 18.7 kJ/m2, more than five times as high as that of neat SAN resin (3.8 kJ/m2). Scanning electron microscopy (SEM) examination confirmed that the primary reason of the improved toughness of the ABS resin was the shear yielding effect of the matrix. Additionally, a melt flow indexer, rotating rheometer, torque rheometer and dynamic mechanical analyzer (DMA) were utilized to analyze the influence of PB-g-SAN concentration on the ABS resin flow behavior. The results showed that the melt flow rate (MFR) of the ABS resin decreased linearly and the complex viscosity (η*) as well as the tensile plateau modulus (E') values increased significantly with the growing concentration of PB-g-SAN. This indicated that the flow behavior of the ABS resin was negatively affected when excess PB-g-SAN concentration was added. The entanglement effect between the SAN copolymer on the PB particles surface and the matrix SAN molecular chains, as well as the PB particle volume effect, were suggested to be the main reasons of the negative effect. This research, we suggest, will provide profound scientific guidance for regulating the mechanical and processing characteristics of the ABS resin. [ABSTRACT FROM AUTHOR]

Fiber-reinforced elastomeric isolators (FREIs) have been proposed as a cost-effective solution for expanding the use of seismic isolation to normal-importance structures. By using lightweight fiber reinforcement and eliminating the attachment plates, FREIs reduce cost while improving the isolation efficiency and reducing tensile stresses in the rubber. However, the flexural flexibility of the fiber allows cross-sectional distortions (i.e., warping) to occur, which significantly impacts the stability of these devices. This paper evaluates the buckling of rectangular, circular, and annular FREIs, taking into account shear warping effects. A planar buckling theory previously proposed by the authors is adapted for the three-dimensional problem, and effective warping rigidities and warping-related areas are derived for the above bearing geometries, accounting for rubber compressibility. To assess the adequacy of the proposed buckling theory and derived warping properties in predicting the buckling of FREIs, a parametric finite element study is conducted. The critical load predictions of the proposed analytical formulation are found to be in excellent agreement with those of the numerical simulations. It is shown that traditional estimations of the buckling load that neglect warping are significantly unconservative. Finally, design recommendations and resources are provided for practice-oriented applications. [ABSTRACT FROM AUTHOR]

This work presents the use of natural rubber (NR) grafted with poly(vinyl propionate) (NR-g-PVP) as an alternative compatibilizer in silica-filled NR compounds. The effects of NR-g-PVP with 10, 20 and 30% grafting on the properties of NR compounds were studied and compared with a commercial coupling agent (bis[3-(triethoxysilyl)propyl] tetrasulfide, TESPT). NR-g-PVP was compatible with silica and NR. The NR-g-PVP reduced filler-filler interactions and increased fillerrubber interactions. The crosslink density decreased with the percentage of grafting due to the steric hindrance. The compatibilization affected the physical and mechanical properties. The interactions of NR-g-PVP with silica via hydrogen bonding and subsequent vulcanization prevented undesirable filler-filler interactions and reduced the absorption of accelerators or basic materials. It caused a good dispersion of silica in the NR matrix and improved physical and mechanical properties. A 10% grafting (G10) was suitable for the compatibilizer in a silica-filled NR compound, showing the largest improvements in tensile properties, tear strength, and hardness. However, TESPT provided better properties than G10. [ABSTRACT FROM AUTHOR]

Thermoplastic vulcanizates (TPVs) were prepared by blending natural rubber (NR) and polypropylene (PP) using dynamic sulfur curing systems with varying accelerator/sulfur ratios: 0.5/2.5, 1.5/1.5, and 2.5/0.5 phr, categorized as conventional (CV), semi-efficient (semi-EV), and efficient (EV). The onset of dynamic vulcanization closely corresponded with scorch time in statically cured NR compounds. Mixing torque decreased over time, reflecting reversion patterns in static curing. The CV system exhibited the highest reversion tendency due to polysulfide linkage breakdown, forming stronger but shorter crosslinks. Dynamic vulcanization induced higher reversion than static curing, influenced by shear and extensional forces. Curing systems caused crosslinking rates, reversion, and crosslink density and distribution variations. Unlike statically cured NR, PP-extracted TPVs exhibited an inverse trend in total crosslink densities and distributions; TPVs primarily comprised shorter crosslinks with opposed total crosslink densities ranked EV > semi-EV > CV. This trend is strongly correlated with superior mechanical strength, toughness, storage modulus, viscosity, and rubber elasticity in the EV-cured TPV. EV system also had the smallest vulcanized NR domains in the PP matrix. [ABSTRACT FROM AUTHOR]

The structure and property relationships of graft copolymers from natural rubber (NR) and polymethyl methacrylate (PMMA) crosslinked with a phenolic resin were investigated. The NR grafted with PMMA (NR-g-PMMA) having different grafting levels was initially prepared by emulsion polymerization before compounding and vulcanization. Then, proton nuclear magnetic resonance and transmission electron microscopy were used to verify the resultant NR-g-PMMAs. The graft copolymers crosslinked with phenolic resin exhibited improvements in various properties. Tensile modulus and tensile strength increased at least 18 and 95%, respectively, over the un-grafted counterpart and further improved with grafting percentage, while the elongation at break decreased accordingly. Storage modulus in rubbery plateau increased while tanδ peak height decreased with PMMA content. Moreover, the thermal stability of the graft copolymers was also improved over that of the plain NR at least 23 °C, depending on MMA contents. These improvements are tentatively attributed to the strong adhesion between NR and PMMA phases, based on interactions between the functional groups of PMMA and hydrogen bonding between phenolic resin crosslinker and PMMA. The results clearly suggest that the phenolic resin could be an effective crosslinker for NR-g-PMMA. [ABSTRACT FROM AUTHOR]

Zinc complexes have a considerable impact on human health and the environment, especially on aquatic wildlife. One of the primary sources of zinc release to the environment is worn rubber particles from tires. The environmental footprint of zinc oxide (ZnO) during production, use, and landfilling has prompted researchers to reduce its use in rubber formulations due to ecological and economic concerns. In this study, composite ZnO materials where ZnO particles are coated on precipitated calcium carbonate (CaCO3) are used in styrene butadiene rubber/butadiene rubber (SBR/BR) compounds, and their performance is compared with white seal ZnO and active ZnO. Trial compounds are prepared on a laboratory scale using composite ZnO materials with ZnO:CaCO3 ratios of 40:60, 60:40, and 90:10, and control compounds with white seal and active ZnO. All compounds are tested to evaluate their curing and physico-mechanical properties. It is observed that the surface area of ZnO plays an essential role in crosslink density and, hence, compound performance. Trial materials have no negative effect on the curing and mechanical properties of the compounds. Thus, it is concluded that composite ZnO materials can be used as alternatives to both white seal ZnO and active ZnO. They have environmental and economic advantages due to their lower ZnO content. The compound recipe has the potential to be used for tire tread compounds. [ABSTRACT FROM AUTHOR]

[Display omitted] • Zinc leached in higher concentration than other metals in all asphalt mixtures. • The main source of zinc may be the aggregates. • All metal concentrations would not exceed the drinking water limit. There are concerns about the potential toxicity of bitumen and recycled materials such as reclaimed asphalt pavements from end-of-life roads and crumb rubber from scrap tires used in asphalt mixtures because they contain metals that may be released into the groundwater. This study investigated the potential metal leaching of laboratory-prepared asphalt mixtures modified with polymer coated rubber (PCR) with wet and dry technology, devulcanized rubber (DVR), compared to an unmodified control mixture and a blend modified with a synthetic polymer (SBS). The objectives were to i) quantify concentrations of metals released, ii) calculate the flux rate, the cumulative mass release, and the assessment ratio for each metal, iii) verify if the metals exceeded the EPA drinking water limit, and, finally, iv) assess the source of metals release. Zinc had the highest concentration among all metals and was present in eluates from all mixtures. The cumulative zinc concentration from DVR mixture was 41% and 34% higher than the control and SBS mixtures, respectively. For PCR wet, the cumulative zinc concentration was 9% higher than the control blend and 1% lower than the SBS mix. The assessment ratio indicated that all metal concentrations would not exceed the drinking water limit, except for zinc, for which further evaluations were required. The main source of zinc may derive from aggregates. This work showed that crumb rubber might not be the only source of metal leaching, and its use in asphalt pavements does not cause a metal leaching higher than other materials. [ABSTRACT FROM AUTHOR]

The crystalline cellulose has captured much attention as reinforcement material in rubber composites, but no successful cases have been found till now. Here, a facile approach of cellulose utilization was proposed by in‐situ regenerating cellulose in dry rubber matrix. Cellulose was dissolved in ionic liquid (IL), and then directly mixed with dry rubber, silica, and other ingredients. Taking advantages of the strong interaction between IL and silica, the dissolution equilibrium of cellulose/IL was destroyed and resulted in the regeneration of cellulose crystals in rubber matrix. The regenerated cellulose appeared at dry blending stage, and showed an ideal rod‐like shape (10–100 nm in diameter and 200–500 nm in length). While it grew in size at curing stage, and finally reached 100–200 nm in diameter and 1–2 μm in length. The regenerated cellulose exhibited pronounced reinforcement efficiency. This methodology has no any waste liquid discharged, and has a promising use in the preparation of cellulose/rubber composites. Highlights: Nanosized rod‐like cellulose was regenerated in dry rubber, instead of latex.Regeneration of cellulose was due to interaction between ionic liquid and silica.The in situ regenerated cellulose dispersed well in cured rubber compounds.The regenerated cellulose exhibited a good reinforcement efficiency in rubber.The whole machining process had no any waste liquid discharged. [ABSTRACT FROM AUTHOR]

Five types of magneto‐rheological elastomers (MREs) based on natural rubber were synthesized by incorporating carbonyl iron particles (CIP) as the primary filler. The objective was to investigate the influence of carbon fiber and magnetic particle content on the mechanical and magneto‐rheological properties of the MREs. Carbon fibers (CF) were further added as secondary reinforcement pre‐modified with polydopamine. The composite's microstructure was examined through scanning electron microscopy (SEM), while the mechanical and magnetodynamic properties were assessed using an electronic universal testing machine and an advanced rotational rheometer. The addition of appropriate amounts of CIP and CF resulted in increased rubber modulus, indicating the formation of a filler‐rubber network and the synergistic effect between carbon fibers as a supporting structure and CIP. Compared to the unfilled MREs, the mechanical and magnetodynamic properties were further improved by adding 2 and 4 wt% CF. These findings demonstrate that employing carbon fibers as reinforcing fillers and incorporating suitable magnetic fillers can enhance the magnetic and mechanical properties of the materials, providing a theoretical basis for the study of MREs' performance. Highlights: CF and CIP synergistically enhance the strength of the rubber matrix.The MR effect is gradually enhanced with the increase of CIP content.Modified CF has a promoting effect on the magnetic responsivity.Magnetic responsivity increases with increasing modified CF content.Improved mechanical and magnetodynamic properties of composites. [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]

Polymer‐based thermal interface materials (TIMs) with excellent thermal conductivity and heat dissipation capabilities play a crucial role in addressing the issue of heat accumulation in advanced integrated electronics. However, establishing improved surface interactions and complete networks to enhance efficient phonon transfer remains a significant challenge. To tackle this problem, surface modification and ice‐templating techniques are commonly employed to create the robust interface crosslinks and continuously thermal conductive pathways. Herein, 2‐mercaptobenzimidazole (MB) was used as a reducing and modifying agent to functionalize graphene oxide (rGO‐MB) within the three‐dimensional networks, which was prepared using a combination of hydrothermal and ice‐templating methods. As a result, the reduced graphene oxide/natural rubber (rGO‐MB/NR) TIMs exhibited a remarkable through‐plane thermal conductivity of 0.93 W m−1 K−1 with a filler loading of 3 wt%. The enhanced interface interactions between rGO‐MB and NR, combined with the establishment of a three‐dimensional network, significantly contributed to the improved thermal conductivity and heat dissipation capabilities. Moreover, the obtained TIMs demonstrated favorable mechanical properties (5.06 MPa, 502%) and excellent insulation performance (3 × 1013 Ω cm). These findings provide the valuable insights into potential solutions for mitigating heat accumulation issues in next‐generation electronics. Highlights: rGO‐MB with thiol groups was obtained by the hydrothermal method.Interactions between rGO‐MB and NR mainly depended on the chemical bonds.rGO‐MB/NR TIMs owned the improved thermal management performance. [ABSTRACT FROM AUTHOR]

Despite the current growing interest in rubber composites with natural organic fillers, there is a lack of kinetic analyses that describe the decomposition of these materials during pyrolysis. For this reason, the main objective of this study was the kinetic analysis and determination of formal kinetic parameters for the pyrolytic decomposition of NR–CEL composites with different cellulose content (0, 30, 45, and 55 phr). Thermogravimetric measurements were made at heating rates of 2, 4, 6, 8, 10, and 20 °C min–1 in the temperature range of 20–600 °C. First, Friedman and KAS model-free methods were applied. Therefore, model-based methods and the model-fitting procedure were used to find the optimal multi-step kinetic model. The proposed final model consists of two parallel processes, which are kinetically independent: A → B → C and D → E → F. For each step, a kinetic triplet was calculated: the apparent activation energy, the pre-exponential factor, and the kinetic parameters of the extended empirical Prout–Tompkins model. The master plots method was used to determine the kinetic decomposition mechanism of the individual steps. It was found that step A → B has the shape of an nth-order model, step B → C mainly follows the diffusion model, the mechanism of step D → E transfers from a random scission kinetics model to an nth-order model with an increasing amount of CEL, and step E → F obeys the chain scission mechanism. [ABSTRACT FROM AUTHOR]

Polystyrene (PS), a widely known amorphous, transparent, glassy, thermoplastic material, is one of the industrially significant polymers for its wide range of applications from packaging to commodity articles. PS is also well-known for its critical drawback of brittleness. This investigation aims towards improving the impact strength of PS by blending it with liquid isoprene rubber (LIR). PS/LIR compositions viz., 85/15, 80/20, 75/25 and 70/30 were mixed and dynamically vulcanized using Haake Rheomixer using sulphur-based vulcanizing system. The dynamically vulcanized blends were subjected to tensile, flexural and impact testing along with thermal and microscopic characterization. From the experimental data, it was evident that there was 110% increment in impact strength of PS matrix with the presence of 15% parts by weight of dynamically vulcanized LIR. The blend with 30% LIR content showed an increased thermal stability of matrix but with a reduction in tensile and flexural strength. The SEM image exhibited the dispersion of fine-sized spherical particles of LIR in PS matrix which is conducive in toughness enhancement. This study offers a novel approach in developing the TPV which is based on oligomer rubber. Also, it is energy efficient approach over solid elastomers. [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]

Cellulose nanocrystals (CNC) obtained from biomass are increasingly demanding as a candidate for rubber composite reinforcement due to their sustainability and environmentally friendly characteristics. This work explored CNC extracted from oil palm trunks, an agricultural waste, for its reinforcing efficacy for natural rubber (NR) composite. To achieve good compatibility of the hydrophilic CNC in non‐polar NR, the NR was modified in a simple and green epoxidation condition via its latex stage. The epoxidized natural rubbers (ENR) containing 15% and 25% epoxide content, symbolized as 15E and 25E, respectively, were prepared. The ENR/CNC nanocomposites were fabricated by mixing CNC aqueous suspension and ENR latex, followed by co‐coagulation by methanol. A low amount of CNC (0.5–5 phr) was incorporated into the rubber and it was found that the ENR/CNC nanocomposites showed improvement in mechanical properties compared to the NR/CNC nanocomposite. The 25E/CNC nanocomposite with 1 phr of CNC achieved a 22.6% increase in tensile strength while the 25E/CNC nanocomposite with 2 phr of CNC resulted in a 27.1% increase in tear strength. The enhanced performance of the fully bio‐based rubber nanocomposites is attributed to the CNC–rubber interaction and good CNC dispersion in the ENR matrices, evidenced by the results of SEM and crosslink density. Highlights: Cellulose nanocrystal (CNC) was successfully obtained from the oil palm trunk.NR was modified into epoxidized natural rubber (ENR) for increased polarity.ENR/CNC mixing was done in a simple and environmentally friendly latex process.Only 2 phr of CNC resulted in a 27.1% increased tear strength of rubber composite.SEM clearly evidenced improvement of CNC–ENR interaction. [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 paper and pulp industry produces lignin as a byproduct, which could be a bio‐based reinforcing filler for rubber. Carboxylated nitrile rubber (XNBR) contains carboxyl groups that form ionic bonds with zinc oxide, potentially increasing compatibility with lignin, compared to usual nonpolar rubbers. This study employed the traditional mixing method, two‐roll mill, to incorporate hardwood Kraft lignin without chemical or physical modification as a reinforcing filler in commercial XNBR. A mixture design of experiments was used to explore the effect on rubber/lignin interaction of the carboxyl group content (from 1% to 7% in blends of XNBR) and the amount of lignin (from 0 to 40 phr). Adding 40 phr of lignin increased stress at 100% in XNBR 7% from 1.7 to 6.3 MPa. In XNBR 1%, the increase was from 1.2 to 1.9 MPa. Lignin showed better interaction and dispersion with XNBR 7%, determined from response surface of G′ at high deformations and SEM, respectively. Loss of thermal transition in DMA indicates interaction through ionic groups. These results show that the presence of carboxyl groups enhances the rubber/lignin interaction. This research open possibilities of compatibilization of lignin, offering guidance for future studies and technologies involving lignin in technical applications. Highlights: Lignin dispersion increased as the carboxyl group content increased to 7% (w/w).Stress at 100% elongation increased 370% with 40 phr of lignin and 7% carboxyl.Rubber/lignin interaction as per G′ increased with carboxyl groups.Loss of thermal transition suggests lignin/carboxy/zinc oxide interaction.Lignin can be used as a reinforcing filler in nitrile carboxylated rubber. [ABSTRACT FROM AUTHOR]

Real‐time detection of different physiological characteristics is crucial for human physical and mental health. A detection system with multimodal sensing capability, high sensitivity, excellent mechanical properties, and environmental stability is highly desirable, but it is still a great challenge. Inspired by the structural gradient of biological tissues, a multifunctional sensor based on carboxylic styrene butadiene rubber (XSBR) and sodium polyacrylate (PAANa) non‐covalently modified MXenes is prepared in this study, in which the MXenes exhibit a gradient distribution and simultaneously formed an orientation arrangement at the bottom of the matrix through the formation of hydrogen bonding interactions with PAANa. The material shows a considerable stretchability of 244% and strength of 7.67 MPa, high electrical conductivity of 55.40 S m‒1, low percolation threshold of 2.48 wt%, and excellent response to strain (gauge factor of 906.7 within 98% strain) and humidity (relative resistance change of 530% within 11–93% relative humidity). Based on the superior performances of the XSBR/PAANa/MXene composite, an integrated detection system is designed to accurately detect respiration and body movements at various scales. This work provides a new perspective for the development of a novel biomimetic functional material for sensor applications. [ABSTRACT FROM AUTHOR]

Aircraft tire is a typical cord-reinforced rubber composite, which consists of unidirectional linear elastic cords and isotropic hyperelastic rubber. The finite element analysis of cord-reinforced rubber composites causes volume-locking and inaccurate modeling due to the approximate incompressibility of the rubber and the complex lay-up of the cord, respectively. Therefore, an embedded model is proposed for finite element analysis of cord-reinforced rubber composites, which is applied to the inflation analysis of aircraft tire. Firstly, a modeling method of cord-reinforced rubber composites is established by embedding cords into rubber to eliminate the degrees of freedom of cords. Secondly, the unidirectional cords and the rubber are described by the linear-elastic and the Mooney–Rivlin hyperelastic constitutive models, respectively. Thirdly, based on the three-field variational principle, the finite element formulation of the cord-reinforced rubber composites is derived to consider the volume deformation of composites. Finally, the effectiveness of the proposed method is verified by specimen tensile and aircraft tire inflation examples. [ABSTRACT FROM AUTHOR]

In order to improve the strength and stability of the rotating support platform, modal and stress characteristics were simulated and calculated based on finite element analysis method. In Hypemesh, the model of the rotating support platform was established. In Abaqus, boundary conditions and loads were defined, and the natural frequencies and vibration modes of the first four orders were obtained. Based on the structure and stress characteristics of the crossbeam, different damping technologies were compared and analyzed, and rubber damping scheme was selected and designed. Through time mileage analysis, the load response and damping effect of damping scheme were verified. The results show that the rubber damping scheme can reduce the maximum stress by more than 15 % without changing the natural frequency substantially. [ABSTRACT FROM AUTHOR]

The effect of γ-radiation dose on the mechanical characteristics and structure of a polymer composite material based on PDI-3B and SKD-KTR low-molecular-mass rubbers and filled with potassium chloride has been studied. It has been shown that an increase in the radiation dose to 200 kGy does not lead to a significant change in ultimate tensile stress and strain. The radiation resistance of the synthesized polymer composite materials is also evidenced by the absence of significant changes in the structure of the irradiated composite. [ABSTRACT FROM AUTHOR]

Natural rubber (NR) consists of mainly cis‐1,4‐polyisoprene with proteins as notable nonrubber components that significantly influence its properties. A relatively unexplored aspect is the role of these proteins in reducing and stabilizing metal ions to form metallic particles. Here, the NR/ZnO composite is successfully prepared by in situ generation of ZnO in the NR latex for the first time. With the aid of the proteins, the amount of ZnO is slightly higher than that formed in the saponified NR latex (SPNR), where some proteins are removed. Importantly, the noncovalent bonds between the proteins and/or amino acids with the ZnO formed in the NR latex can provide the self‐healing behavior of the NR/ZnO composite. However, heating at ≈40 °C is still necessary for reducing the healing time and increasing the self‐healing efficiency of the composite. Nevertheless, greater noncovalent bonds within NR/ZnO hinder rubber molecular chain interdiffusion and rearrangement essential for self‐healing behavior in uncross‐linked rubber, resulting in lower healing efficiency compared to SPNR/ZnO. This study underscores the significance of proteins and/or amino acids on NR's properties, despite their minor presence. Without sophisticated NR modification, this is a very simple and low‐cost technique to achieve the NR/ZnO composite with self‐healing behavior. [ABSTRACT FROM AUTHOR]

Vulcanization is a chemical modification of rubber that requires a considerable amount of thermal energy. To save thermal energy, the kinetics of rubber vulcanization should be improved. In this article, the curing properties of rubber vulcanization are thoroughly investigated using the moving die rheometer (MDR) technique. To enhance the kinetics in different stages of ZnO-based sulfur vulcanization systems, small amounts of MgO were added. The results revealed that the small amount of 1 to 2 phr (per hundred grams of rubber) of MgO in the controlled 5 phr ZnO-based curing systems can significantly improve the curing kinetics. For example, the optimum curing time of 1 phr MgO added to the 5 phr ZnO-containing semi-efficient vulcanization system at different temperatures was more than half that of the controlled 5 phr ZnO-only compound. While maintaining a similar rate of vulcanization, the vulcanization temperature can be reduced by up to 20 °C by using MgO as a co-cure activator, which exhibits similar or better rheometric mechanical properties compared to the controlled compounds. With the addition of MgO as a co-cure activator, the vulcanization reactions become very fast, enabling vulcanization to be completed, even at the boiling point of water (100 °C) with an affordable curing time (<1 h). By reducing the vulcanization temperature, the scorch safety time can be enhanced in the ZnO/MgO-based binary cure activator-containing vulcanizates. Overall, MgO could be a potential candidate as a co-cure activator with ZnO for the vulcanization of rubber, offering better economical and eco-friendly methods. [ABSTRACT FROM AUTHOR]

In recent years, hydroacoustic transducers made of PZT/epoxy composites have been extensively employed in underwater detection, communication, and recognition for their high energy conversion efficiency. Despite the ease with which these transducers can be formed into complex shapes, their lack of mechanical flexibility limits their versatility across various sizes of underwater vehicles. This study introduces a novel flexible piezoelectric composite hydroacoustic transducer (FPCHT) based on a 1-3 PZT-5A/silicone rubber composite and an island–bridge flexible electrode, which can break the limitations of existing hydroacoustic transducers that do not have flexibility. The finite element method is used to optimize the structural parameters of high-performance 1-3 FPC. A large-sized (187 mm × 47 mm × 5.12 mm) FPC is fabricated using an improved cutting–filling method and packaged into the FPCHT. Compared with the planar rigid PZT/epoxy composite hydroacoustic transducer (RPCHT) of the same size, the TVR (186.5 db) of the FPCHT has increased by about 7 dB, indicating that it has better acoustic radiation performance and electroacoustic conversion efficiency. Furthermore, its electroacoustic performance exhibits excellent stability under different bending states. Therefore, the FPCHT with high electroacoustic performance is an ideal substitute for the existing RPCHT and promotes the development of hydroacoustic transducers towards flexibility and portability. [ABSTRACT FROM AUTHOR]

The special mechanical properties of natural rubber originate from the stretching of the network chains (i.e., cis‐1,4‐polyisoprene chains) in the rubber network. The chains with various lengths exhibit various relative extensions, leading to various normalized energy contributions to the mechanical properties of rubber. However, the stretching behaviors of cis‐1,4‐polyisoprene chains with different lengths are not studied clearly. Here, the stretching behavior, which is the basis for analyzing the normalized energy contribution, is obtained by the modified freely jointed chain model. Next, using a new statistical model, i.e., the two‐component quantum‐mechanics Gaussian (TCQMG) model, the relative extension–length relationship of network chains is determined. Combining the above results, the energy contributions of network chains with different lengths are analyzed. The results show that long and short chains show different stretching states. The following can be explained by these results: short chains play an important role in the mechanical properties of rubber. As the network chain density increases, the average length of the chains decreases, leading to the variation of the normalized extensions. It is found that the variation of the normalized extensions is responsible for both the effects of the network chain density and network chain length on the mechanical properties of rubber. [ABSTRACT FROM AUTHOR]