EPDM Research Articles

Study on long-term waterproof performance and failure mechanism of shield tunnel gasket under compression

To study the long-term durability and failure mechanism of ethylene propylene diene monomer (EPDM) rubber gasket in shield segment joints under water-rich environment and compression. In this paper, the hydrothermal accelerated aging test of EPDM rubber gasket under compression was carried out, and the height loss and mechanical properties degradation of the gasket were revealed. Taking the height loss rate as the deterioration index, a time-varying model of gasket aging under water-rich and compressive conditions was established, and the conversion relationship between the test aging and the service life of the gasket under compression was obtained. Furthermore, based on the modified Mooney-Rivlin constitutive, an Euler-Lagrange coupling numerical model considering the effect of water flow is constructed, and the waterproof failure mechanism of the gasket after aging is analyzed. Finally, considering the influence of segment joint deformation in actual service, the evolution law of long-term waterproof performance of gasket under the action of joint dislocation and opening is predicted. The results show that the existence of compression force will seriously aggravate the aging of the gasket, resulting in significant irreversible deformation, and the height loss rate difference between the compressed and uncompressed gaskets is more than 10 times. The waterproof failure process of the gasket after compression aging can be divided into four stages: initial infiltration-splitting-penetration-leakage. During the actual compression service period, the residual performance of the gasket decreases nonlinearly with the increase of the service time, and the loss is extremely significant in the first 5 years of service, and then gradually slows down with the increase of time. In addition, when the joint opening reaches 6 mm, the effective service life of the gasket is shortened to 100 years, the opening amount is 12 mm, and the service life is reduced to 50 years.

Influence of rubber particle inputs on nitrogen removal efficiency of bioretention systems.

Bioretention systems effectively capture rubber particles and other microplastics in stormwater runoff. However, it is uncertain whether long-term particle accumulation affects pollutant removal efficacy. This study investigated the impact of various concentrations of ethylene-propylene-diene-monomer (EPDM) particles (0, 50, 100, and 400 mg/L) on bioretention system nitrogen removal performance. The input of EPDM during short-duration (2 h) rainfall favored the removal of nitrogen, and the total nitrogen effluent concentration of the bioretention system with EPDM was reduced by 0.59-1.52 mg/L compared with that of the system without EPDM. In addition, the input of EPDM reduced the negative effects of drought. During long-duration (24 h) rainfall, higher concentrations of EPDM led to lower nitrate-nitrogen concentrations in the effluent. The bioretention system with EPDM required less time for nitrate-nitrogen removal to reach 50% than that without EPDM input. Microbial community analysis showed that EPDM increased the relative total abundance of denitrifying bacteria (such as Dechloromonas, Zoogloea, Ramlibacter, and Aeromonas) by 7.25-10.26%, which improved the denitrification capacity of the system.

Current Advancements in the Behavior Analysis of EPDM Elastomers in Peripheral Applications of the Cathodic Side of PEMFC Systems

This review examines the latest developments in the study of how Ethylene Propylene Diene Monomer (EPDM) elastomers behave in peripheral applications of Proton Exchange Membrane Fuel Cells (PEMFCs), specifically on the cathodic side. The review highlights the crucial role of EPDM in maintaining the integrity and efficiency of PEMFCs in challenging conditions characterized by varying temperatures, humidity, and acidic environments. The study examines the impact of various additives and vulcanization procedures on EPDM's mechanical and chemical properties, demonstrating enhancements in tensile strength, thermal stability, and chemical resistance. The study also investigates the compounding methods and selection of fillers, such as silica and carbon black, to optimize the performance of EPDM. Additionally, the effects of prolonged operational circumstances on EPDM's mechanical integrity and aging resistance in PEMFCs are being examined. This research emphasizes EPDM's suitability for long-term use in fuel cell systems. This review aims to guide the design of more durable and efficient PEMFC systems by optimizing the use of EPDM elastomers.

Study on the effect of halloysite nanotubes on the mechanical properties and swelling resistance of ethylene-propylene diene monomer (EPDM)/nitrile butadiene rubber (NBR) blend nanocomposites

Abstract Research was undertaken to explore the alteration of natural halloysite nanotubes (HNTs) using a blend of resorcinol and hexamethylenetetramine (RH), (γ-aminopropyl) triethoxysilane (APTES), and diethoxydimethyl silane (DMS). This investigation delved into the impact of incorporating various proportions of RH-modified HNTs (RH-HNTs), APTES-modified HNTs (APTES-HNTs), DMS-modified HNTs (DMS-HNTs), and unmodified HNTs into ethylene propylene diene monomer (EPDM) and nitrile butadiene rubber (NBR) for their potential as seal materials. The study assessed key properties such as tensile strength, stress at 100% elongation, elongation at break, compression set, hardness, and swelling and abrasion resistance to gauge the influence of HNT additions. As nanofiller content increased, the crosslinking rate rose, while scorch time and optimum cure time decreased. Findings indicated that incorporating nanofillers at 6 phr compositions notably enhanced composite strength initially, with a subsequent slight reduction. However, rebound resilience diminished with increasing filler content, though composite hardness experienced a slight improvement. Mole percent uptake decreased, particularly at higher filler loadings. Notably, systems containing 6 phr RH-HNTs exhibited a 140% increase in tensile strength. FESEM micrographs depicted a rough fracture surface with well-dispersed nanofillers within EPDM/NBR. Additionally, compression set data illustrated enhanced composite performance under compression, crucial for seal applications.

Study on flame retardant and smoke suppression of EPDM by sepiolite expansion flame retardant system

AbstractA large amount of smoke will be produced during the combustion of ethylene propylene diene monomer(EPDM), which seriously endangers the environment and personal safety. In this study, K‐SEP was obtained by modifying sepiolite with KH550, and two bio‐based flame retardant and smoke suppression systems AEGS and PEGS were prepared by combining ammonium polyphosphate intumescent flame retardant system (AEG) and piperazine pyrophosphate intumescent flame retardant system (PEG), respectively. The flame retardant and smoke suppression properties of AEGS and PEGS on EPDM matrix composites were investigated. The experimental results show that the LOI values of EPDM/AEGS3 and EPDM/PEGS3 composites with 3 phr K‐SEP are 8.1% and 5.5% higher than those of the blank samples without sepiolite. TSP decreased by 26.3% and 14.3% respectively, which proved that sepiolite has important research value in the field of flame retardant and smoke suppression of polymer materials.

The effect of rubber and plastic mass ratio on the compatibilized ethylene propylene diene monomer/polypropylene TPV with shape memory behavior

AbstractThermoplastic vulcanizate (TPV) with shape memory performance showed great application potential in various fields. In this work, the effect of the mass ratio of ethylene propylene diene monomer (EPDM) and polypropylene (PP) on the performance of TPV with sea island microstructure compatibilized by magnesium maleate (MgMA) and maleic anhydride (MAH) was studied. The compatibilized TPV 70/30 and TPV 60/40 obtained good shape memory property with the shape fixity ratio (Rf) and shape recovery ratio (Rr) of 87.3%, 96.7% and 91%, 86.6% respectively. Rf increased with more PP content and decreased with more EPDM content, however Rr decreased with more PP content and increased with more EPDM content. The maximum Rf of 95.4% and the maximum Rr of 100% of TPV were obtained at the EPDM/PP mass ratio of 20/80 and 80/20 respectively. The tensile strength and elongation at break of TPV increased with more PP content in the blend. The result of DMA, Fourier transform infrared (FTIR), and SEM demonstrated the compatibility effect of MgMA and MAH on EPDM and PP interface.

Exploring the wear resistance of EPDM‐PAE/SWCNTs composites with a novel perspective of micro‐network structure

AbstractThe effect of single‐walled carbon nanotubes (SWCNTs) on the crosslinking network structure of Ethylene Propylene Diene Monomers (EPDM)—Polyamide elastomers (PAE) is investigated in detail using Hansen Solubility Parameter (HSP) theory. Rheological method and scanning electron microscopy (SEM) are used to investigate the effect of SWCNTs on the molecular chain movement and their interaction with the filler network of EPDM‐PAE. The DIN abrasion test is conducted to obtain the effect of SWCNTs on the wear characteristics of EPDM‐PAE/SWCNTs composites. The linear synergistic relationship between crosslinking density and wear volume indicates that the change in wear properties is contributed by the micro‐network structure. The addition of SWCNTs increases the chemical crosslinking density and improves the wear properties of EPDM‐PAE. However, the decrease in the physical crosslinking density leads to an increase in the degree of internal friction within the network structure, resulting in a decrease in the wear performance. Changes in wear resistance can be related to the micro‐network structure, which provides a novel approach to studying the wear characteristics of high‐performance elastomers. It is also an innovative work based on the network structure to guide the preparation of new wear‐resistant elastomeric materials.

Influence of Deformation Speed on the Tearing Energy of Carbon Black-Filled EPDM Rubber

Influence of Deformation Speed on the Tearing Energy of Carbon Black-Filled EPDM Rubber

Influence of pyrolysis temperature on biochar properties: Applications as a reinforcing filler in sbr and epdm elastomeric compounds

This study investigates the effect of pyrolysis temperature on the properties of biochar derived from Pinus spp. wood waste and its application as a reinforcing filler in styrene-butadiene rubber (SBR) and ethylene-propylene-diene monomer (EPDM) elastomeric compounds. Biochar was produced at 400°C and 900°C and its effects on the mechanical properties of the elastomers were analyzed. The results indicate that biochar produced at 900°C has higher fixed carbon content and lower volatile matter, resulting in improved mechanical properties such as tensile strength and elongation at break compared to biochar produced at 400°C. Despite a lower specific surface area, the irregular surface structure of biochar enhances its interaction with elastomers, providing a semi-reinforcement. This study highlights the potential of high-temperature biochar as a sustainable alternative to conventional fillers such as carbon black, contributing to the development of environmentally friendly materials from biomass waste. The results support further exploration of the role of biochar in elastomer applications, highlighting its environmental and mechanical benefits.

Synthesis of ion exchange film based on chemical grafting of styrene onto polyethylene/EPDM rubber blend for thorium removal.

Chemical grafting of low-density polyethylene film blended with ethylene propylene diene monomer rubber (PE/EPDM) using styrene monomer followed by a sulfonation process was investigated. Different factors affecting the grafting process, such as monomer and initiator concentrations, time of reaction, and grafting temperature, were studied. Sulfonation of the grafted films was carried out using chlorosulfonic acid in dichloromethane. Characterization of the grafted and sulfonated films was performed using ATR-FTIR, SEM, TGA, and XRD instruments. The grafting was successfully performed in aqueous media using sodium bisulfite as initiator, reaching a grafting yield of 130% and an ion exchange capacity of 1.2 meq/g. The removal of thorium ions from aqueous solution was studied using the obtained ion exchange films. The results showed that the maximum adsorption capacity of Th(IV) was 177.5 mg. g-1 (pH = 3, 298 K and 60 min). Removal isotherm and Kinetics were investigated, and the results revealed that the adsorption process was chemisorption homogeneous monolayer adsorption, exothermic, and spontaneous.

Impact of Aging on Tensile Properties of EPDM, TPV, and eco-TPV: A Comparative Study Across Diverse Environments

Abstract This study examines the effects of aging on the tensile characteristics of Ethylene Propylene Diene Monomer (EPDM), Thermoplastic Vulcanizates (TPV), and Eco-friendly Thermoplastic Vulcanizates (Eco TPV) in different conditions. The samples underwent thermal aging at a temperature of 90°C and were immersed in sulfuric acid solutions with varying concentrations (1M, 0.1M, and 0.001M) for a duration of 1000 hours at the same temperature. The findings revealed that EPDM demonstrated the maximum tensile strength and a moderate level of elongation and breakage. Furthermore, it retained substantial mechanical integrity after undergoing aging, thereby establishing it as the most resilient material among those evaluated. The thermoplastic vulcanizate (TPV) exhibited intermediate tensile strength and elongation, but experienced significant deterioration when exposed to very acidic environments while Eco TPV had lower tensile strength but good chemical stability. The stress-strain behavior and compression set tests emphasized EPDM’s exceptional durability and ability to recover elastically. The pH measurements of the immersion solutions indicated an elevation caused by the release of alkaline chemicals from the rubber components, especially in the 1M solution.

Comprehensive Study of EPDM Rubber Properties: Temperature-Dependent Stiffness, Tensile Behavior and FEA Calibration

Abstract This work examines the temperature-dependent stiffness of Ethylene Propylene Diene Monomer (EPDM) rubber using tensile testing and Dynamic Mechanical Analysis (DMA). Additionally, it provides an appropriate model for Finite Element Analysis (FEA). The tensile tests indicate that EPDM has high rigidity and minimal elongation at −40°C, intermediate characteristics at 23°C, and a decrease in stiffness with rising temperature, up to 80°C. Nevertheless, a sudden rise in rigidity is seen at a temperature of 125°C, which may be ascribed to the strengthening influence of carbon black. The DMA findings confirm this pattern, demonstrating an upward trend in storage modulus and stiffness as temperature increases. At the same time, tan delta and loss modulus fall, suggesting a reduction in viscoelastic damping. The calibration of the Finite Element Analysis (FEA) model, using the Arruda-Boyce, Yeoh 3D, and Mooney-Rivlin 5-parameter models, determines that the Arruda-Boyce model is the most precise in accurately replicating the experimental data. The results indicate that the improved resistance to heat and increased rigidity of EPDM at high temperatures are affected by its material composition. However, more investigation is required to have a comprehensive understanding of the underlying processes.

Synergistically ceramization of rubber system for fire safety cable by sepiolite functionalized with boron-based nanoparticles

In this research, a novel ethylene propylene diene monomer rubber (EPDM) formulation for cable with high ceramization efficiency was prepared by the addition of functionalized sepiolite with boron fluxing compound nanoparticles (SEPTB) obtained by precipitation route. Non-functionalized sepiolite (SEP) has been incorporated to the system for reference. EPDM materials were characterized by standardized tests measuring their behavior against fire and important improvements were observed, especially in terms of smoke production (25% reduction of the smoke production compared with the formulation using SEP) presenting a remarkable behaviour against dripping and self-extinction when a flame is directly applied. The mechanism of ceramization under fire conditions was discussed. It was found that EPDM system with SEPTB additive transformed into a rigid ceramic after treating at 1000°C. In this particular case, the ceramization was more efficient due to the sepiolite transformation to enstatite at lower temperatures (∼750 vs ∼850°C) combined with the “in situ” formation of a glassy phase which notably enhances the reinforcement of the char layer by forming a reinforcing 3D enstatite fibers net structure that reduces smoke production and even totally avoids the dripping of melted polymer by the action of the heat in a fire event. This work provides new insights for the preparation of high-performance synergist additive based on sepiolite for the enhancement of fire retardance of EPDM system for cable applications.

Effects of Sulfuric Acid-Water Immersion on the Properties of Ethylene Propylene Diene Monomer, Thermoplastic Vulcanizates, and Eco-Friendly Thermoplastic Vulcanizates

Abstract This research investigates the impact of sulfuric acid-water solutions on the physico-chemical characteristics of ethylene propylene diene monomer rubber (EPDM), thermoplastic vulcanizates (TPV), and ECO TPV materials. We evaluated the deterioration of these materials by subjecting them to acidic environments and using methods such as differential scanning calorimetry (DSC), volume and weight measurements, hardness measures, and scanning electron microscopy (SEM). The samples were submerged in solutions of H2SO4 with concentrations of 1M, 0.1M, and 0.001M at a temperature of 90°C for a duration of 1000 h. The results indicated that EPDM had superior chemical and thermal stability, accompanied by negligible changes in weight and volume. The TPV exhibited moderate stability, however the ECO TPV showed severe deterioration, as seen by major increases in weight and volume, as well as notable changes in DSC profiles. Surface degradation and cracking, especially in ECO TPV samples, were observed using SEM investigation. The hardness results indicated little changes in hardness after exposure to the various chemical aging techniques. The results indicate that EPDM and TPV are better suited for use in acidic conditions, such as fuel-cell systems. However, ECO TPV may need extra stabilization in order to enhance its endurance.

The Influence of Aluminosilicate Cenospheres on the Structure and Properties of Elastomeric Composite Materials Based on Ethylene–Propylene–Diene Elastomers

The Influence of Aluminosilicate Cenospheres on the Structure and Properties of Elastomeric Composite Materials Based on Ethylene–Propylene–Diene Elastomers

Improved mechanical performance and swelling resistance of ethylene propylene diene monomer/styrene butadiene rubber nanocomposites through the incorporation of graphene oxide as a reinforcing filler

Improved mechanical performance and swelling resistance of ethylene propylene diene monomer/styrene butadiene rubber nanocomposites through the incorporation of graphene oxide as a reinforcing filler

Micromechanical insights for enhancing the rebound resilience of sealing materials based on TPV

Thermoplastic vulcanizate (TPV) with fascinating high elasticity has been received the ongoing research attention in the application of sealing system for the engineering machine. However, there still exists one factor, the plastic strain of plastic matrix adjacent to rubber particles in equatorial direction, which has greatly inhibited the resilience improvement of TPV. Traditional in-situ online experiments could not accurately obtain and quantify the stress-strain evolution behavior of heterogeneous rubber-plastic materials, crucial for resilience. Herein, one kind of TPV based on polyamide thermoplastic elastomer (TPAE) and ethylene-propylene-diene monomer (EPDM) with outstanding rebound resilience has been fabricated via introducing the interfacial compatibilization reaction and reinforcing particles during the melt-reactive blending. One three-dimensional representative volume element (3D-RVE) model has been established to analyze the deformation mechanism of such designed TPV in this work compared with that for TPV based on polypropylene (PP) and EPDM. By analyzing the forces on the RVE mesh units, it could reveal that the TPAE matrix exhibited more uniform stress transfer behavior at the thin ligament, and the recovery behavior of TPV matrix mainly occurred at the thin ligament. This work would provide important value for the preparation of new high elastic TPV materials from a microscopic level.

Organic reinforcement of an ethylene propylene diene monomer with the in situ synthesis of a polyimide dispersed phase by reactive extrusion

AbstractEthylene‐propylene‐diene monomer rubber, grafted with maleic anhydride functions (EPDM‐g‐MA) was organically reinforced by reactive extrusion from the in situ synthesis of a polyimide (PI) phase. The blends were reactively processed at 200°C in a twin‐screw extruder, with the PI content varying from 5 to 40 wt%. Transmission Electron Microscopy (TEM) revealed a very fine nodular dispersion of the PI phase with diameters ranging from 130 to 240 nm depending on the PI concentration. The reinforcement of the elastomer was evidenced with a sharp increase of the Young's modulus and the tensile strength, and the stiffness of the material was further increased with the PI content. The linear viscoelastic regime, as measured by the variation in storage modulus as a function of strain, was unaffected by this organic reinforcement, thus opening up an original way of controlling the Payne effect. Additionally, the cross‐linking of the blend with 20 wt% of PI with dicumyl peroxide (DCP) showed that the PI phase did not impact the creation of the cross‐linked network. The decrease of the swelling ratio and the improvement of the elastic recovery suggested that EPDM‐g‐PI copolymers can create a second network in the material, resulting in a higher apparent cross‐linking density. The mechanical properties of the cured blend showed a doubling of the Young's modulus and maximal stress values compared to those obtained for the pure matrix as well as a constant strain at break.Highlights Ethylene‐propylene‐diene monomer rubber, grafted with maleic anhydride functions (EPDM‐g‐MA) was organically reinforced by reactive extrusion. The reinforcement was obtained from the in situ synthesis of a polyimide (PI) phase. The Young's modulus of cross‐linked EPDM containing 20 wt% PI was doubled. The linear viscoelastic regime was unaffected by this organic reinforcement. This original way of reinforcement opens the control of the Payne effect.

Elastomeric Sensor-Triboelectric Nanogenerator Coupled System for Multimodal Strain Sensing and Organic Vapor Detection.

Stretchable, flexible sensors are one of the most critical components of smart wearable electronics and Internet of Things (IoT), thereby attracting multipronged research interest in the last decades. Following miniaturization and multicomponent development of several sensors in one could further propel the demand for wireless, multimodal platforms. Greener substitutes to conventional sensors that can operate in a self-powered configuration are highly desirable in terms of all-in-one sensor utilities. However, fabrication of composite-based ultrastretchable, self-powered sensors with multifunctionality, robustness, and conformability is still only partially achieved and, therefore, demands further investigation. In this work, we report a triboelectric nanogenerator (TENG)-based multifunctional strain and organic vapor sensor using cross-linked ethylene propylene diene monomer (EPDM) elastomer and conducting carbon black as active fillers in the presence of an ionic liquid. The resulting piezoresistive sensor demonstrates ultrahigh gauge factor (GF > 220k) and wide range strain sensitivity and is, therefore, suitable for subtle-to-high frequency motion detection devices. Supported by excellent triboelectric outputs (force sensitivity 0.5 V/N in the range of 50-300 N, maximum output voltage VOC ∼ 178 V, short circuit current ISC ∼ 18 μA, maximum power density 0.11 mW/cm2), the hybrid sensors offer remarkable mechanical toughness and seamless voltage generation under contact-separation, even after several thousand cycles of operations. Furthermore, the sensor substrates exhibited reproducible organic vapor-sensing behavior, with high responsivity of 1.92 and 1 for ethanol and acetone, respectively, under flowing vapor conditions. This work lays a strong foundation for developing a truly multimodal, TENG-based, self-powered organic vapor and strain sensors.

Recycling of EPDM rubber via thermomechanical devulcanization: Batch and continuous operations

Thermomechanical devulcanization is a possible solution for the circular economy of EPDM rubber, as it removes covalent crosslinks from vulcanizates, resulting in a material similar to uncured rubber mixes. In this paper, sulfur-cured EPDM rubber was treated with thermomechanical stimuli: a) processing on a two-roll mill and in an internal mixer, and b) twin-screw extrusion. Horikx's analysis indicated a 75 % decrease in crosslink density with little polymer chain degradation. The resulting devulcanizates and non-devulcanized rubber crumb were added to the original rubber mix, yielding samples with 0, 25, 50, 75 and 100 wt% recycled rubber contents. Revulcanizates with up to 50 wt% devulcanizate content retained the tensile strength of the original rubber with a slight increase in modulus. Ultimately, batch devulcanization had the most promising results, and extrusion devulcanization was also more beneficial than using non-devulcanized rubber crumb. Crosslink density and morphological tests also support these findings.