Rubber Content Research Articles

Stress level dependent behavior of sand-rubber mixtures

This study investigates the mechanical behavior of sand-rubber mixtures, focusing on the influence of stress levels. Quantitative analysis reveals significant effects of stress levels on void ratio and coordination number, which become more pronounced with increasing rubber content. Small-strain stiffness could be affected by stress level by demonstrating unified relationships between small-strain stiffness and conventional state variables, with the coefficients of determination for fitted relationships increasing from 0.66 to 0.95 as rubber content increases from 0% to 80%. This is attributed to the impact of stress levels on conventional state variables. Alternative state variables that exclude rubber materials more effectively describe the small-strain characteristics of sand-rubber mixtures, suggesting that rubber materials should be excluded when considering these characteristics in practical engineering for conservation purposes. The stress level effect is also evident in the variation of stress ratios with axial strain, particularly when rubber content exceeds 25%, showing that higher stress levels restrict the mobilization of stress ratios for rubber materials. This study highlights the importance of considering stress level effects in the mechanical analysis of sand-rubber mixtures, which exhibit unique characteristics compared to natural sands in both compression and shearing behavior.

Methyl jasmonate improves rubber production and quality in Lactuca Serriola.

The increase in demand for natural rubber has led to the search for alternative sources. Lactuca serriola is emerging as a promising candidate, as the quality of the natural rubber it produces is comparable to that of the Pará Rubber Plant, Hevea brasiliensis. This study examines the effect of methyl jasmonate (MeJA), a known elicitor, on the expression of key rubber biosynthesis pathway genes (HMGR1, HMGS1, CPT2, and SRPP1) in the latex of L. serriola plants. The expression levels of these genes increased significantly after the foliar application of 200 and 400 µM MeJA. The highest relative expression level for HMGR1, HMGS1, CPT2 and SRPP1 was 3.74, 18.56, 11.91and 16.59 fold respectively. Furthermore, the rubber content in L. serriola showed a significant rise post-treatment compared to the control with increasing the level of MeJA (6.19%, 7.24% and 7.85% which correspond to 0, 200 and 400 µM). Gel permeation chromatography revealed an augmentation in the molecular weight of extracted natural rubber from treated plants. Samples treated with 400 µM of MeJA had the highest molecular weight (1570 kg mol-1) compared to control (1186 kg mol-1). This study has demonstrated that MeJA, through the regulation of rubber biosynthesis genes, is capable of enhancing the quality and quantity of natural rubber extracted from alternative sources, such as L. serriola.

Constitutive behaviour of a granular matrix containing coal mine waste intermixed with rubber crumbs

AbstractTraditional railway substructure materials (i.e., natural crushed rock aggregates used for ballast and capping layers) degrade under service loads, incurring higher periodic maintenance costs compared to recycled materials. Using recycled waste materials such as coal wash and rubber crumbs for infrastructure upgrades not only reduces construction and maintenance costs but also supports environmental sustainability. By exploring unconventional avenues, earlier studies have delved into the viability of blending rubber crumbs (RC) and coal wash (CW) as an innovative substitute for traditional railway substructure materials, with a specific focus on the capping layer. This study introduces a semi-empirical constitutive model to simulate the response of mixtures of coal wash and rubber crumbs (CWRC) using the bounding surface plasticity framework. The novelty of this study is that a modified volumetric strain expression is introduced to capture the compressibility of rubber, thus enabling a more accurate representation of the internal deformation of rubber within the granular matrix. The variation of rubber content in the mixture is captured by the corresponding critical state void ratio surface and the hardening modulus. The theoretical model is then calibrated and validated using static drained triaxial test data for CWRC mixtures as well as mixtures of steel furnace slag, coal wash, and rubber crumbs (SFS + CW + RC).

Chemical and Rheological Evaluation of the Ageing Behaviour of High-Content Crumb Rubber Asphalt Binder.

High-Content Crumb Rubber Asphalt (HCRA) binder improves road performance and address waste tyre pollution, yet its ageing behaviour is not fully understood. In this study, 70# neat asphalt binder and HCRA with rubber contents of 35% and 50% were selected and aged through the Thin Film Oven Test (TFOT) and Pressure Ageing Vessel (PAV) tests. FTIR (Fourier Transform Infrared Spectroscopy) and DSR (Dynamic Shear Rheometer) were employed to investigate their chemical composition and rheological properties. The FTIR results show that HCRA's chemical test results are similar to those of 70#, but HCRA is more susceptible to ageing. I(C=C) strength decreases with age. The DSR results show that HCRA outperforms 70# neat asphalt binder in terms of viscoelasticity, high temperature performance and fatigue resistance, and exhibits greater resistance to ageing. The ageing index (AI) was obtained through a calculation using the formula, and overall, 70# neat asphalt binder is more sensitive to ageing behaviour and less resistant to ageing, and HCRA is particularly outstanding for fatigue resistance. A strong correlation is observed between chemical composition and some rheological property indicators. Therefore, we are able to predict the rheological properties using chemical composition indicators. This study provides insight into the ageing behaviour of a neat asphalt binder and an HCRA binder and demonstrates that the HCRA binder outperforms conventional asphalt in several performance areas. It also provides theoretical support for the consumption of waste tyres to prepare high content crumb rubber asphalt.

Experimental Study on the Influence of Crumb Rubber on Temperature Susceptibility of Asphalt for Railway Application in the Tropics

The granular sub-ballast in conventional ballasted trackbed structure, though cheap and easy to construct, requires frequent maintenance, and cannot protect the subgrade against water infiltration. However, asphaltic sub-ballast in asphalt-ballast trackbed can reduce stress on the subgrade and provide a waterproofing layer against water infiltration. Asphalt binder is however, susceptible to temperature fluctuations. The aim of this study therefore is to investigate whether the addition of crumb rubber to asphalt binder could reduce the susceptibility of asphalt to temperature, and thus, improve its performance. The main objective of this research is the addition of four different ratios of crumb rubber; 1, 2, 3, and 4%, of size 0.3 mm to bitumen or asphalt 60/70 grade. The results showed that penetration of the asphalt binder reduced from 66.70 to 59.20 mm at 4% rubber content, implying that the modified asphalt became harder with addition of crumb rubber and thus, can withstand temperatures variations in asphaltic pavements. Softening point, used to test temperature susceptibility of bitumen, increased from 49.10°C to 52.80°C at 4% crumb rubber content, implying that crumb rubber modified asphalt can withstand elevated temperatures in asphaltic pavements, in the tropics. Flashpoint increased from 295.20 to 296.12°C, fire point also increased from 306.50°C to 308.28°C, Specific gravity of the unmodified and crumb rubber-modified asphalt did not change significantly because crumb rubber is not very flammable, Viscosity at 135°C increased from 338.00 to 360.00 cSt at crumb rubber content of 4%, Ductility at 25°C reduced from 122.40 cm to 79.40 cm at 4% crumb rubber content, implying that crumb rubber made asphalt stiffer. This study concludes that crumb rubber can reduce the susceptibility of asphalt to temperature changes.

Stress-Dilatancy Behavior of Highly Elastic Rubber-Added Cohesionless Materials.

Dilatancy is commonly defined as the ratio of the rates of plastic volumetric strain to plastic deviatoric strain, denoted as Dp. Owing to the high modulus of elasticity, the elastic volumetric and deviatoric strain rates under shear stress in conventional cohesionless materials are negligible. Therefore, using the ratio of the rates of total volumetric to deviatoric strain (Dt) as an approximation is common in studying stress-dilatancy behavior and calibrating dilatancy model parameters. This approach is also common in the study of rubber-added cohesionless materials (RCM). However, RCM with a common range of rubber content exhibit a significantly lower modulus of elasticity compared to conventional cohesionless materials. Further research is needed to evaluate the potential impact of elastic strain rates in RCM on stress-dilatancy analysis. Therefore, comparisons were conducted on the stress-dilatancy responses of a series of tests on RCM, where dilatancy is calculated by Dp and Dt, respectively. Furthermore, a modified method for calibrating the parameters of a state-dependent dilatancy model considering Dp is presented. It turns out that Dp is better suited and more precise for dilatancy analysis on highly elastic RCM. Additionally, the dilatancy model can more precisely capture the test results of RCM with parameters calibrated by the proposed method.

Functional analysis of TkWRKY33: A key regulator in drought-induced natural rubber synthesis in Taraxacum kok-saghyz

WRKY proteins, which form a transcription factor superfamily that responds to jasmonic acid (JA) signals, regulate various developmental processes and stress responses in plants, including Taraxacum kok-saghyz (TKS). TKS serves as an ideal model plant for studying rubber production and lays the foundation for a comprehensive understanding of JA-mediated regulation of natural rubber synthesis. In the present study, we screened and identified a valuable transcription factor, TkWRKY33, based on transcriptome data from TKS in response to JA. We investigated its role in the regulation of natural rubber synthesis within the JA signaling pathway and its function in response to drought stress. Through protein-protein interactions and transcriptional regulation analysis, we found that TkWRKY33 may regulate natural rubber synthesis through the JA-TkMPK3-TkWRKY33-(TkGGPS5/TkACAT8) cascade pathway, possibly by participating in JA-activated mitogen-activated protein kinase (MAPK) signaling. Overexpression of TkWRKY33 in tobacco, along with functional analysis of drought resistance and comparative analysis of natural rubber content after drought stress, revealed that TkWRKY33 not only enhances plant drought resistance by regulating the expression of genes related to reactive oxygen species (ROS) scavenging through the JA signaling pathway, but also has a close relationship with the signal transduction pathway mediated by the JA hormone in regulating natural rubber synthesis.The TkWRKY33 is recognized as a valuable transcription factor, which likely plays a role in regulating natural rubber biosynthesis through the JA-activated MAPK cascade signaling pathway JA-TkMPK3-TkWRKY33-(TkGGPS5/TkACAT8).

Mechanical, thermal, and water absorption properties of HDPE/barley straw composites incorporating waste rubber

This study investigates the mechanical, thermal, and water absorption properties of high-density polyethylene (HDPE) composites filled with barley straw and varying amounts of waste rubber. The research aims to develop sustainable materials that repurpose agricultural and industrial waste while addressing resource scarcity and waste management challenges. Composites were prepared using a twin-rotor mixer and hydraulic press, with waste rubber content varying from 0 to 20 wt%. Mechanical properties were evaluated through tensile testing, thermal behavior was analyzed using TGA, DTG, and DSC, and long-term water absorption was measured. Results show that increasing waste rubber content from 0 to 20% led to a decrease in tensile strength (11.3 to 8.9 MPa) and tensile modulus (1760 to 790 MPa), while relative extension increased (2.4–5.9%). Thermal analysis revealed a slight reduction in onset degradation temperature (270 °C to 240 °C) and increased char residue (8–18%) with higher rubber content. Water absorption decreased significantly, from 12 to 13% to 6–7% after 600 h of immersion, as waste rubber content increased. These findings demonstrate that incorporating waste rubber into HDPE/barley straw composites results in materials with enhanced flexibility and water resistance at the cost of some strength and stiffness. In conclusion, the results of this study offer a clear pathway for the development of sustainable polymer composites that have broad potential applications across industries like construction, marine infrastructure, automotive, and packaging. By replacing traditional, resource-intensive materials with eco-friendly alternatives, these composites not only provide functional benefits but also support global efforts toward sustainable development and environmental conservation.

Effect of layering and pre-loading on the dynamic properties of sand-rubber specimens in resonant column tests

AbstractSeveral studies show that scrap tyre rubber mixed with sand is an effective and sustainable method for mitigating vibrations. The dynamic and cyclic response of this composite soil has already been investigated. However, layered sand-rubber configurations have not been considered yet. This study reports findings of resonant column tests on three types of specimen: (a) sand-only or rubber-only, (b) layered sand-rubber, and (c) sand-rubber mixtures. The analysis allowed for an evaluation of the maximum shear modulus and its degradation with strain over a wide range of confining stress and shear strain. The evolution of the damping ratio with strain was determined analogously. Effects of pre-loading and pre-straining were also considered. The results show that the behaviour of layered specimens is much more similar to that of pure rubber than to sand-rubber mixtures, with very low shear modulus values, smaller degradation of stiffness with strain and pre-loading, and higher damping. For example, at the confining stress of 100 kPa and rubber content of 0/33.3/50/67.7/100% by volume, the small strain shear moduli for sand-rubber mixtures are equal to 98.3/30.4/15.4/7.1/1.3 MPa and 98.3/3.6-4.2/2.4-2.8/2.1/1.3 MPa for sand-rubber layered specimens, depending on the arrangement of layers. A shear beam model is shown to be adequate for calculating the response of the layered specimens comprising layers of large stiffness contrast.

Small Strain Stiffness of Sand‐Rubber Mixtures With Particle Size Disparity Effect

ABSTRACTThis 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.

Study on high-temperature emission behaviors of crumb rubber modified asphalt: Experimental analysis and molecular simulation approach

The harmful emissions produced during the manufacturing and construction processes of crumb rubber modified asphalt (CRMA) significantly hinder its widespread application. Addressing this issue hinges on a thorough investigation into the mechanism governing its high-temperature emissions. This study employed microscale testing methods to analyze the microstructure and chemical property disparities between CRMA and base asphalt (BA). Subsequently, the impacts of varying crumb rubber (CR) content, experimental temperature, and sulfur stabilizer dosage on the high-temperature emissions of CRMA were investigated. Furthermore, comparative analyses of the molecular weight distribution, emission species, and CR crosslink density in asphalt after the fume experiment were conducted to further elucidate the high-temperature emission mechanisms. Finally, molecular simulation techniques were employed to analyze the interactions between CR and the four fraction molecules of asphalt at the microscale. The results indicated that the fume release volume of CRMA initially decreased and then increased with the addition of CR, while both the experimental temperature and sulfur stabilizer content exhibited a positive correlation with emission volume. CR reduced the volatilization of some small molecular hydrocarbons in the BA by absorbing light fractions. Meanwhile, excessive swelling caused the crosslinking density of CR to decrease by 77 %, which led to the release of toxic substances. At 20% CR content, the overall emissions of CRMA achieve their lowest level; however, the emission of toxic gases does not diminish. Molecular simulations have also confirmed the above results, showing that there is a strong interaction between CR and the light fractions. Compared with asphaltene molecules, rubber molecules had higher molecular polarity and stronger adsorption behavior for light fraction molecules.

Structural features of polylactide and natural rubber films produced by solution casting

Composite film samples of polylactide-natural rubber with a rubber content of 5, 10 and 15 wt. % were obtained by the solution method. The study of morphology showed the presence of rubber inclusions in the form of drops in the polylactide matrix. Thermophysical characteristics were determined by differential scanning calorimetry. It was determined that when rubber was added, the peak of cold crystallization of polylactide disappears on melting thermograms, the melting temperature decreases by 1–4°C compared to 100% polylactide. The structure of the obtained compositions was studied by nuclear magnetic resonance, electron paramagnetic resonance, and X-ray diffraction. The diffraction patterns of the samples contain reflections characteristic of the crystalline α-form of polylactide.

Emission Risk and Inhibition Technology of Asphalt Fume from Crumb Rubber Modified Asphalt

Crumb rubber-modified asphalt mixtures have been proven to have extensive utilization value in road engineering. However, the rubber releases more fumes during the construction period, which causes severe harm to human health and the environment. This research focused on the emission risk of asphalt fume from crumb rubber-modified asphalt, and then the inhibition technology was also optimized. Firstly, the emission behavior and the hazardous evaluation of the asphalt fume from crumb rubber-modified asphalt were investigated. Then, the characteristics of the inhibition materials were evaluated. Finally, the reduction in the emission of inhibited crumb rubber-modified asphalt fume was identified, and the optimized formula was determined based on the inhibition effect, rheological properties, and cost. The results indicate that crumb rubber-modified asphalts release more fume components with an increment in the temperature and crumb rubber content. Desulfurized rubber reduces the release of H2S and NO. Benzene compounds, including paraxylene, toluene, and benzene, are the most released pollutants that harm human health, especially DS CRA 20% and CRA 50%. Kaolin powder and expanded graphite have a sufficient pore structure and volume, the addition of which reduces the release of pollutants while possibly promoting the release of NO and H2S. Their addition also has a significant control effect on the release of particulate matter at 170 °C and 185 °C. With the consideration of emissions, rheological properties, and cost, CRA 40%-EG2%-KL2% was determined as the optimization formula. This research is helpful to the application of crumb rubber-modified asphalt in road construction and maintenance.

Upcycling of waste rubber using pelletized artificial geopolymer aggregate technology

The utilization of waste rubber as aggregates shows both environmentally friendly features and high cost-efficiency in construction, but may cause poor workability such as rubber flotation and agglomeration. To address the above issues, the pelletization method was adopted to produce rubberized artificial geopolymer aggregates (R-GPA), and the effects of different rubber modification methods and rubber contents were investigated through pelletization technologies, mechanical tests, X-ray computed tomography (XCT) and backscattered electron with energy-dispersive spectroscopy (BSE-EDS). Results showed that the combined modification with NaOH solution and silane coupling agent presented the most effective surface modification efficiency. According to microscopic analysis, rubber modification could effectively enhance the rubber-matrix interface. The produced R-GPA could thus possess an oven-dried particle density within 1500–1800 kg/m³, a water absorption of 7%–10.5%, and a pelletization efficiency over 98%, which provided a new insight into the value-added utilization of waste rubber and the promotion of artificial aggregate technologies.

Performance evaluation of bio-oil and high rubber content modified asphalt: More effective waste utilization

In this study, the bio-oil was used to reduce the viscosity and preparation temperature of high content of rubber-modified asphalt. The high rubber content modified bio-asphalt (RMBA) was prepared, the rubber and bio-oil contents were 20 %-30 % and 5 %-15 % (mass ratio of neat asphalt), respectively. The viscosity, temperature sweep (TS), frequency sweep (FS), multi-stress creep recovery (MSCR), and bending beam rheometer (BBR) tests were performed to assess the properties of RMBA. The Fourier Transform infrared spectroscopy (FTIR), Fluorescence microscopy (FM), and Scanning electron microscope (SEM) tests were conducted to explore the microscopic morphology of RMBA. Besides, the economic analysis and life cycle assessment (LCA) were assessed. Bio-oil contributed to the viscosity-reduction of the RMBA. When the rubber content was 30 %, the viscosity decreased by 48.16 % with a bio-oil content of 15 %. The temperature and frequency sensitivity of RMBA were lower than neat asphalt. Rubber improved the creep recovery and anti-rutting deformation behavior for bio-asphalt. The absorption peaks appeared at 1010 and 1038 cm−1, which represented the SO function group. The rubber did not absorb enough bio-oil for solubilization. This resulted in the functional group of SO appeared in 30 %+B-10 % and R-30 %+B-15 %. FM and SEM test results indicated that the rubber in RMBA exists in different states: undissolved rubber and dissolved rubber. The high content rubber could be partially dissolved in bio-asphalt and retained its elastic properties. The dissolved rubber particles exhibited a large crosslinked network structure. The raw material cost of RMBA decreased significantly with the rise of rubber and bio-oil contents. The reasonable application of waste rubber is beneficial to the alleviation of black pollution. The efficient application of rubber and bio-oil could contribute to the development of waste utilization and green transportation.

A machine learning model for predicting the mechanical strength of cement-based materials filled with waste rubber modified by PVA

As demand for sustainable building materials rises, the use of waste rubber in civil engineering is gaining attention. This study proposes a method to modify waste rubber using polyvinyl alcohol (PVA) to enhance its material properties and expand its applications. A dataset was created focusing on the mechanical strength of cementitious materials incorporating PVA-modified waste rubber, and multiple machine learning methods were used to develop regression prediction models, particularly evaluating the support vector regression (SVR) model. Results show that the SVR model outperforms others, achieving mean squared errors of 1.21 and 0.33, and mean absolute errors of 2.06 and 0.15. Analysis indicates a negative correlation between waste rubber content and the water-to-cohesive ratio (w/c) with strength indexes, while a positive correlation exists between curing age and PVA. Notably, waste rubber content significantly affects strength. The mechanical strength of cementitious materials was notably enhanced by PVA-modified waste rubber, likely due to PVA's dispersion and bridging effects. This study presents a novel approach to sustainably recycle waste rubber, highlighting its potential in construction materials.

Compatibilizing and toughening of the styrene and acrylonitrile copolymer and core‐shell impact modifier obtained by agglomerate technologies

AbstractParticle size distribution and the compatibility of core‐shell impact modifiers play a crucial role in determining the mechanical properties of the resin. This study presents the synthesis of a core‐shell impact modifier, a copolymer of polybutadiene grafted with styrene and acrylonitrile (PBL‐g‐SAN), using emulsion polymerization to enhance the mechanical properties of SAN resin. Polymer agglomeration technologies were employed to increase the particle size of polybutadiene latex, resulting in particles approximately 300 nm in diameter. Moreover, the effects of core‐shell modifiers with different constitutions on the mechanical properties of ABS resin were investigated. By optimizing the grafting polymerization process, improvements in impact strength of ABS resin were observed. When the St/AN ratio of the core‐shell modifier is 75/25, with a core‐shell ratio of 60/40 and MMA content at 2.5%, the impact strength of ABS resin reaches its peak while maintaining high tensile strength. The incorporation of methyl methacrylate improved the dispersion of core‐shell modifiers in SAN resin. Compared to commercial ABS resins with the same SAN and rubber content, the modified resin demonstrated a nearly 20% improvement in impact performance, and significant reductions in both production time and costs due to the polymer agglomeration method.Highlights The 300 nm polybutadiene latex was synthesized by polymer agglomeration technology. The relationship between the composition of these core‐shell modifiers and the mechanical properties of ABS resin was explored. The ABS resin with impact strength exceeding 20% of commercial material is prepared.

Performance of geocell reinforced rubber sand mixtures under undrained triaxial test

Large quantities of scrap tires are produced by the automobile industry each year, which causes disposal challenges and impacts the environment. However, scrap tires exhibit various properties, including tensile strength, abrasion resistance, durability, thermal conductivity, elasticity, and more. Due to their versatile characteristics, these scrap tires can be utilized as construction materials for various civil engineering works to reduce their negative environmental effects and conserve natural resources. This study aims to understand the shear strength behaviours exhibited by geocell-reinforced mixtures of rubber and sand through the unconsolidated undrained triaxial test. Various parameters, including rubber sizes (425 μm to 12 mm), rubber contents (10% to 40% by volume), confining pressures (50 to 300 kPa), and geocell heights (0.2H to 0.8H, where H is the height of triaxial sample), were systematically examined to understand their impact on shear strength characteristics. The experimental findings reveal that deviatoric stress is enhanced with increasing confining pressure and rubber sizes. The maximum benefits of the rubber-sand mixture were observed at 30% rubber content. Geocell-reinforced rubber sand mixture has a higher shear strength with respect to the unreinforced mixture. Furthermore, the energy absorption capacity of the geocell-reinforced rubber sand mixtures was much better as compared to either the clean sand or rubber-sand mixture. The findings of this research demonstrate that geocellreinforced rubber sand mixtures are suitable for various geotechnical engineering works.

Evaluation and characterization of rubber powder distribution on the ductility of rubber asphalt from the mesoscopic view

To investigate the effects of rubber powder’s distribution on the ductility of RA, the force-ductility test (FDT) was conducted with rubber contents of 15, 20, 25, and 30 wt%, and the results demonstrated that the dense rubber powder in RA will reduce its ductility. The microscopic tests discovered that the rubber powder distribution significantly mechanisms of how the state of RP impacts the ductility of RA impacted the mechanical performance of RA. Subsequently, based on the Monte Carlo method and Python, models of RA were established, and FDT was simulated from the mesoscopic view. The findings demonstrated that the dense distribution of rubber powder led to poor ductility of RA. Consequentially, this study offered an innovative mesoscopic perspective of studying RA, particularly the multiple impacts of rubber powder distribution on RA.

Enhanced abrasion resistance of NR/BR/TBIR composites through the synergistic reinforcement of carbon black and graphene oxide: Structural influence and mechanistic insights

AbstractCarbon black (CB) with different structural parameters together with graphene oxide were formed into uniformly dispersed filler network for enhancing the abrasion resistance of natural rubber/cis‐1,4‐polybutadiene rubber/trans‐1,4‐poly(isoprene‐butadiene) rubber blended composites. It showed that the CB structural parameters, such as specific surface area, surface activity and structural degree affected the formation of bound rubber. With the increase of bound rubber content, the homogeneity of filler network structure was improved and the filler‐rubber interaction was enhanced, resulting in a remarkable increase in the mechanical properties, thermal performance and abrasion resistance of the composites. Among the different types of CB, the composites filled with high‐structural‐degree CB of N134 had DIN wear volume as low as 76 mm3 and exhibited 19.5% higher abrasion resistance than N330. Wear surface observations and wear mechanism analyses showed that the increase in abrasion resistance was related to the improvement in tear resistance, hardness and thermal properties of the composites. Multiple linear regression analyses yielded that the structural degree in the structural parameters of CB had a significant correlation effect on the formation of bound rubber, and there was a strong linear relationship between the abrasion resistance of the composites and the content of bound rubber.Highlights Trans‐1,4‐poly(isoprene‐butadiene) rubber as compatibilizer for NR/BR blends. Synergistic enhancement of rubber using carbon black and graphene oxide. Carbon black with high structural degree promotes the formation of bound rubber. Described correlation between CB structural parameters and abrasion resistance of rubber.