Propylene Diene Monomer Rubber Research Articles

Study on the application of Flory–Huggins interaction parameters in swelling behavior and crosslink density of HNBR/EPDM blend

The sorption and permeation coefficients of four amine solvents in hydrogenated nitrile rubber/ethylene propylene diene monomer rubber (HNBR/EPDM) blends were calculated, and the transport mechanism of solvents was verified by the Peppas–Sahlin model. The Flory–Huggins interaction parameters (χ: χ1D and χ3D) between solvent and HNBR/EPDM blend were obtained by one-dimensional solubility parameter (SP-1D) and three-dimensional solubility parameter (SP-3D), respectively. The predictive powers of χ1D and χ3D on the transport behavior of amine solvents permeating in HNBR/EPDM blends were studied and compared. The application of χ1D and χ3D in the calculation of cross-linking density was explored. It is found that the χ3D is more suitable for predicting the transport behavior of solvents with both strong and weak polarity in the blends, while the χ1D is only available for the solvents with poor polarity. However, the χ1D is more appropriate to calculate the crosslink densities of HNBR/EPDM blends.

Determination of three‐dimensional solubility parameters of HNBR/EPDM blends and the transport behaviors in ester solvents

AbstractTo enrich the research on the solubility parameter of rubber blends, equilibrium swelling tests combined with computer software, Hansen solubility parameter in practice (HSPiP), were employed to deeply investigate the three‐dimensional solubility parameters (HSP) of hydrogenated nitrile rubber/ethylene propylene diene monomer rubber (HNBR/EPDM) blends. And the transport behaviors of four ester solvents have been studied through the calculation of sorption and permeation coefficients. It is found that the HSP values of HNBR/EPDM blends show linear relationships with the mass fraction of HNBR. And a linear equation has been obtained for the calculation of the solubility parameters of HNBR/EPDM blends. Sorption and permeation coefficients show two‐stage upward linear relationships with the HNBR concentration, which can be attributed to the sea phase in the blend playing a decisive role in the transport behaviors of solvents. Moreover, the trend of the selective adsorption of the solvent is more obvious in the permeating process than that at the final equilibrium swelling state. The achievements can provide important guidance for evaluating the liquid resistance of the HNBR/EPDM‐based rubber products in industrial and automotive applications.

Entrapment of Airborne Particles via Simulated Highway Noise-Induced Piezoelectricity in PMMA and EPDM

The US highway system features a huge flux of energy transportation in terms of weight, speed, volume, flow density, and noise levels, with accompanying environmental effects. The adverse effects of high-volume traffic cause health concerns for nearby residential areas. Both chronic and acute exposure to PM 2.5 have detrimental effects on respiratory and cardiovascular health, and motor vehicles contribute 25–35% of direct PM 2.5 emissions. In addition to traffic-related pollutants, residing near major roadways is also associated with exposure to increased noise, and both affect the health and quality of life of residents. While regulatory and policy actions may reduce some exposures, engineering means may offer novel and significant methods to address these critical health and environmental issues. The goal of this study was to harvest highway-noise energy to induce surface charge via a piezoelectric material to entrap airborne particles, including PM 2.5. In this study, we experimentally investigated the piezoelectric effect of a polymethyl methacrylate (PMMA) sheet and ethylene propylene diene monomer (EPDM) rubber foam on the entrapment of copper (II)-2,4 pentanedione powder (Cu II powder). Appreciable voltages were induced on the surfaces of the PMMA via mechanical vibrations, leading to the effective entrapment of the Cu II powder. The EPDM rubber foam was found to attract a large amount of Cu II powder under simulated highway noise in a wide range, of 30–70 dB, and at frequencies of 700–1300 Hz, generated by using a loudspeaker. The amount of Cu II powder entrapped on the EPDM rubber-foam surfaces was found to scale with the SPL, but was independent of frequency. The experimental findings from this research provide a valuable base for the design of a robust piezoelectric system that is self-powered by harvesting the wasted sound energy from highway noise and reduces the amount of airborne particles over highways for effective environmental control.

Development of polyaniline/ethylene propylene diene monomer rubber (PANI/EPDM) conductive blend by in situ polymerization technique

Development of polyaniline/ethylene propylene diene monomer rubber (PANI/EPDM) conductive blend by in situ polymerization technique

Characterization technique of gases permeation properties in polymers: H2, He, N2 and Ar gas

We demonstrate a simple experimental technology for characterizing the gas permeation properties of H2, He, N2 and Ar absorbed in polymers. This is based on the volumetric measurement of released gas and an upgraded diffusion analysis program after high-pressure exposure. Three channel measurements of sorption content of gases emitted from polymers after decompression are simultaneously conducted, and then, the gas uptake/diffusivity as a function of exposed pressure are determined in nitrile butadiene rubber (NBR), ethylene propylene diene monomer (EPDM) rubbers, low-density polyethylene (LDPE) and high-density polyethylene (HDPE), which are used for gas sealing materials under high pressure. The pressure-dependent gas transport behaviors of the four gases are presented and compared. Gas sorption follows Henry’s law up to 9 MPa, while pressure-dependent diffusion behavior is not observed below 6 MPa. The magnitude of the diffusivity of the four gases decreases in the order DHe > DH2 > DAr > DN2 in all polymers, closely related to the kinetic diameter of the gas molecules. The dependence of gas species on solubility is in contrast to that on diffusivity. The linear correlation between logarithmic solubility and critical temperature of the gas molecule was newly observed.

Svojstva poroznih asfaltnih mješavina s etilen propilen-dienskim monomerom

Porous asphalt pavements are environmentally friendly permeable road pavements. There is a need to improve the strength performance of porous asphalt mixtures. Waste Ethylene Propylene Diene Monomer (EPDM) rubber modification of porous asphalt mixtures is investigated in this study. The mixture was initially designed for the selected mix aggregate gradation. Waste EPDM rubber scraps were replaced with filler materials at the rate of 2 % and 4 % of the total aggregate weight. Performance tests were conducted on test specimens. The EPDM rubber scraps improved the elasticity and strength properties of PA mixtures.

Influence of Gamma-Irradiation on Swelling Percentage, Flammability Resistance and Morphological Analysis of EPDM/Sepiolite Composites

Gamma irradiation is a particularly effective method for inducing crosslinking, which leads to improved composite characteristics. The effects of gamma irradiation on swelling percentage, flammability and morphological analysis were investigated. Ethylene Propylene Diene Monomer (EPDM) rubber composites were prepared with various amounts from 10-60 phr (part per hundred part of rubber) of the sepiolite particles using a two-roll mill machine. The composites were subjected to 50 kGy of gamma irradiation and compared with unirradiated composites. The results demonstrate a reduced in swelling percentage at all sepiolite loadings. The crosslinks of rubber chains into sepiolite/EPDM composites generated by gamma rays resulted in improvements in the swelling resistance. The irradiation composites, however showed lower flammability resistance to the non-irradiated composites.

Gas chromatography techniques to evaluate the hydrogen permeation characteristics in rubber: ethylene propylene diene monomer

We established an ex-situ technique for evaluating hydrogen gas permeability by thermal desorption analysis (TDA) gas chromatography (GC) and by self-developed diffusion analysis software. Absorbed hydrogen mass in rubber, related to the GC-peak area, is recorded as a function of elapsed time after decompressing the hydrogen under high-pressure. From the charging amount (CH0) and diffusivity (D) obtained by the developed diffusion analysis program, the solubility(S) and permeability(P) is evaluated via Henry’s law and P = SD, respectively. The techniques were applied to ethylene propylene diene monomer (EPDM) rubber, sealing material candidates in hydrogen infrastructures. EPDM sample mixed with carbon black fillers showed dual hydrogen diffusion behaviors, whereas EPDM sample without carbon black showed a single hydrogen diffusion behavior. There was no appreciable pressure or size dependence on D, S and P. P are consistent with that measured by different researcher within the expanded uncertainty.

A modus operandi toward interfacial enhancement of ethylene propylene diene monomer rubber/ polybenzoxazine blends using EPDM‐grafted‐vinyltrimethoxysilane copolymer

AbstractCompatibilization of polymer blends is performed to obtain synergistic effects in physical and mechanical properties. The present work demonstrates the ability of vinyltrimethoxysilane‐grafted‐ethylene propylene diene monomer rubber (VTMS‐g‐EPDM) to improve the compatibility between EPDM and polybenzoxazine (PB). EPDM reacted with 5 phr of VTMS showed the highest grafting efficiency as well as a relatively low gel content, and was added to EPDM/PB blends. The addition of 8 phr of compatibilizer to 70/30 (w/w) EPDM/PB reduced the dispersed PB droplet size from 3.1 μm to 800 nm. Effects of various blend compositions at constant dosage of compatibilizer (8 phr) on the swelling behavior and tensile properties of the samples were also studied. The tensile strength increased from 12 to 14.5 MPa upon adding the compatibilizer at 50/50 blend ratio of EPDM/PB; however, the increase in the PB content had no significant impact on the tensile strength in both compatibilized and non‐compatibilized samples.

Thermal Conductivity and Mechanical Properties of the Rubber Stopper Filled with ZnO Nanograins

ZnO nanograins (nZnO) were synthesized by a precipitation method. The nZnO exhibited the average grain size of ~30 nm and the specific surface area of 28.24 m2 g-1. Then, it was incorporated into the ethylene propylene diene monomer (EPDM) rubber and produced to be a rubber stopper. This work studied the effect of nZnO and conventional ZnO (cZnO) as a cure activator on the thermal conductivity and mechanical properties of the rubber stopper. As the content of nZnO increased, the thermal conductivity and mechanical properties are also increased. The obtained results could be reduced successfully from 5 to 2 parts per hundred parts of rubber (phr) compared with a cZnO because nZnO provides a satisfactory thermal conductivity and mechanical properties. Moreover, it also gives uniform completely vulcanized for thick rubber product due to swelling value (Q) between outer and inner portion of rubber stopper is less difference. In this work is concluded that the dosage, grain sizes and grain boundary of ZnO are effective parameter in the thermal conductivity and mechanical properties of the rubber stopper.

Investigation of Mechanical Properties of Magneto-Rheological Ethylene Propylene Diene Monomer and Natural Rubber Type Synthetic Rubbers for Both Isotropic and Anisotropic Situations

Manyeto-reolojik (MR) malzemeler dis manyetik alan uygulamalariyla tersinir ve hizli bir sekilde kontrol edilebilen reolojik ozelliklere sahip akilli(smart) malzeme sinifindandir. Gelisen teknoloji kosullari goz onune alindiginda kaucuk turu akilli malzemeler manyeto-reolojik etkilerle beraber daha fonksiyonel bir kullanima sahip olmustur. Bu calismada, manyeto-reolojik Etilen Propilen Dien Monomer (EPDM) ve Dogal Kaucuk (NR) turu sentetik kaucuklarin izotrop ve anizotrop durumda tek eksenli yukleme altindaki mekanik ozelliklerinin incelenmesi amaclanmistir. Bu tur kompozit malzemeler geleneksel sicak kalip sistemi yardimiyla izotrop (homojen) ve anizotrop (hizalanmis) olarak ferromanyetik toz ilave edilerek ve manyetik alan uygulanarak elde edilmistir. Elde edilen kompozit malzemelere manyetik alanin etkisi incelenmistir. Calismada EPDM sentetik kaucuk malzemesinin aksine NR kaucugunun akilli malzeme ozelligine daha yatkin oldugu gozlemlenmistir.

Effect of modified clay and Mg(OH)2 on the properties of ethylene propylene diene monomer/silicon rubber nanocomposites

Ethylene propylene diene monomer and silicon rubber were blended in different ratios, and the physico-mechanical properties and the cure characteristics were studied. It was found that the ratio 60/40 phr (parts per hundred parts of rubber) of ethylene propylene diene monomer/silicon rubber exhibited the best value. Therefore, this ratio was loaded with the required concentration of each, unmodified clay and the two modified clays (one modified with distilled water and the other with anionic surfactant), to prepare rubber nanocomposites. The modified clays were characterized by X-ray diffraction and transmission electron microscopy. The properties of nanocomposites were investigated in terms of the cure characteristics, scanning electron microscopy, flammability and mechanical and thermal properties. It was noted that nanocomposites loaded with modified clays resulted in the highest cure and mechanical properties. The scanning electron microscopy and X-ray diffraction revealed the exfoliation of the nanoclay layers with uniform dispersion and good interaction between the nanoclay particles and rubber matrix. The thermal stability and flammability of nanocomposites were improved by the addition of different concentrations of Mg(OH)2.

Influence of cross-linked system on morphology and properties of thermoplastic vulcanizates based on isotactic polypropylene and ethylene propylene diene monomer

Thermoplastic vulcanizates (TPVs) based on isotactic polypropylene (iPP) and oil-free/oil-extended ethylene propylene diene monomer (EPDM) rubber were prepared by dynamic vulcanization. Their rheological and tensile properties as well as morphological peculiarities were examined and compared with those of uncured blends. Vulcanization was performed using two types of cross-linking agents: phenolic resin and sulfur-accelerating systems. Dynamic vulcanization was shown to change the melt viscosity of oil-free and oil-extended iPP/EPDM blends. These changes were found to depend on both rubber content and type of vulcanizing agent. For identical composition, the melt viscosity of TPVs cured by sulfur system was higher than that of blends cured by phenolic resin system (PRS). Dynamic vulcanization by PRS decreased tensile properties of TPVs in comparison with sulfur vulcanization. Morphology of iPP/EPDM blends studied by atomic force microscope was found to be dependent on the ratio of components, type of elastomer, and nature of vulcanizing system.

Effects of shear stress and subcritical water on devulcanization of styrene–butadiene rubber based ground tire rubber in a twin‐screw extruder

ABSTRACTThe devulcanization reaction of styrene–butadiene rubber (SBR) based ground tire rubber (GTR) in GTR/ethylene–propylene–diene monomer rubber (EPDM) blend was investigated through a compound‐induced reaction by increasing screw rotation speed and being in the presence of subcritical water. The effects of temperature, pressure, screw rotation speed, or promoting agents on the gel content, Mooney viscosity, and Fourier transform infrared spectra of the sol of the devulcanized blends (devulcanized ground tire rubber (DGTR)/EPDM) were measured, and the mechanical properties and microstructures of the revulcanized blend ((DGTR/EPDM)/SBR) were characterized. The results show that subcritical water as a swelling agent and reaction medium promotes the devulcanization reaction, increases the selectivity of the crosslink breakage, keeps the extrusion material from oxidative degradation, reduces the gel particle size of the devulcanized blends, and significantly improves the mechanical properties of the revulcanized SBR/(DGTR/EPDM) blends. In subcritical water, the suitable promoting agents (alkylphenol polysulfide 450, hydrogen peroxide H2O2, or 450/H2O2) accelerate the devulcanization reaction, keep the double bond content, and lead to further decrease of the gel content and Mooney viscosity of the devulcanized blends and further increase of the mechanical properties of the revulcanized SBR/(DGTR/EPDM) blends. Especially the compound promoting agent (450/H2O2) improves the selectivity of the crosslink breakage in devulcanization of SBR‐based GTR. When 450/H2O2 is added as a compound promoting agent at the best reaction condition in subcritical water (200°C, 1.6 MPa and 1000 rpm), the tensile strength and elongation at break of the revulcanized SBR/(DGTR/EPDM) blends reach to 85.4% and 201% of vulcanized SBR (24.0 MPa, 356%), respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1845–1854, 2013

Asset management frameworks for outdoor composite insulators

Power supply utilities are continuously working to maintain reliable and efficient electrical networks that meet the growing demand for electricity. This is a complex task in which appropriate maintenance, refurbishment and replacement policies for all the assets are critical. Optimising business processes through these constitutes a key challenge of balancing service quality and stakeholder value. Here we present two frameworks that can be used to effectively condition monitor both ethylene propylene diene monomer (EPDM) and silicone rubber (SiR) composite insulators during their lifetime in service. The frameworks are tools to assist asset management decision making. The first framework is derived from a generalized dielectric ageing framework and a more specific one on composite insulators that points out the elements that govern composite insulator materials? ageing on power transmission and distribution lines. The second framework defines four aged states in relation to the risk to failure that a composite insulator has in service before its replacement. Properties of materials that can be measured in order to identify ageing are reviewed. The techniques available as engineering tools for measuring these properties are introduced. These are distinguished as techniques that can be carried out on-line and off-line, and as destructive and non-destructive tests. These techniques are then reviewed in the context of monitoring and maintaining reliable and efficient operation of power networks.

Toughening of glass fiber reinforced Nylon 66 with EPDMMAH: Dynamic mechanical, rheological, and morphological investigations

AbstractIn this research the variation of mechanical and rheological properties of the composite as a function of different processing parameters and ethylene propylene diene monomer (EPDM) rubber content was studied. The optimum amount of dicumyl peroxide (DCP) to achieve the highest percentage of grafting of maleic anhydride to EPDM was obtained by Fourier transform infrared (FTIR) spectroscopy. In general, immiscibility between nylon 66 and EPDM, and their high interfacial tension makes their blending difficult. Maleic anhydride was grafted to EPDM to reduce interfacial tension between two phases. Also the blends were prepared at highest possible speed of mixing (screw speed in extrusion) and lowest temperature to reach a well mixed sample which can be seen in scanning electron microscopy (SEM) images and impact strength results. Dynamic mechanical thermal analysis (DMTA) tests were conducted to evaluate the miscibility of the components and to measure the glass transition temperature of the blends. Rheological measurement showed that the viscosities of the components of the blend getting closer to each other when EPDM content, time of mixing and shear rate increase.

Caracterização por FT-IR da superfície de borracha EPDM tratada via plasma por micro-ondas

A superfície de uma borracha de etileno-propileno-dieno (EPDM) vulcanizada foi modificada via plasma por microondas, com gases Ar, Ar/O2, N2/O2 e N2/H2, tendo como objetivo melhorar as propriedades adesivas da superfície. A técnica FT-IR/UATR foi escolhida para caracterizar as superfícies após tratamento, pois apresentou menor interferência dos ingredientes da formulação da EPDM, dentre as técnicas analisadas (ATR/KRS-5 e Ge). Grupos oxigenados foram inseridos na superfície da amostra tratada, mesmo quando não foi utilizado o oxigênio, pois estes grupos foram formados quando a superfície ativada foi exposta à atmosfera. Já em tratamentos contendo N2, grupos oxigenados e possíveis grupos nitrogenados foram identificados por FT-IR. Redução nos valores do ângulo de contato, aumento no trabalho de adesão e aumento no ensaio de resistência ao descascamento (EPDM × Poliuretano) foram observados após tratamento com Ar e N2/H2, resultando em melhora nas propriedades adesivas da superfície tratada.

Evaluation of Flashover Voltage Mechanisms on Hydrophobic Polymer Insulators with Artificial Neural Network Approach

This paper presents an experimental measurement of ac 50 Hz flashover voltage (kV) of hydrophobic polymer insulators. Hundred thirty five different testing conditions were used to evaluate the electrical performance of hydrophobic surfaces of composite polymer insulators. The study of flashover voltages depend on the silicone rubber (SiR) content (%) in Ethylene propylene diene monomer (EPDM) rubber, water conductivity (µS/cm), volume of water droplet (ml) and number of water droplets on the surface of polymer insulators. Artificial neural network (ANN) is used successfully to model nonlinear functions which are difficult to model using classical methods. ANN can estimate the values of flashover voltage (kV) for different polymer insulators. The proposed network is trained using different environmental wet condition such as; water conductivity, volume of water droplet and number of water droplets on the surfaces of composite different polymer. After training, the network can estimate the flashover voltage for different inputs. A comparison between the laboratory measurements of flashover voltages and computational results of ANN were convergent. The results obtained from applying ANN show that it can be used to model the data with accuracy of 96%. These results prove that ANN can be considered a successful model to evaluate the electrical performance of hydrophobic polymer insulators and predicts the best hydrophobic composite surface that withstands higher flashover voltage under wet contaminated weather condition.

Comparative study on mechanical, thermal, viscoelastic and rheological properties of vulcanised EPDM rubber

In this study, mechanical, thermal and rheological properties of vulcanised ethylene propylene diene monomer (EPDM) rubber containing different amounts of vulcanising agent, filler, paraffinic oil and stearic acid were compared. Moreover, reaction rate constant of the curing reaction has been calculated from the results of the rheological tests, and relative change of rate constant with the change of additives was studied by a new method. Thermal gravimetric analysis with in situ Fourier transform infrared (FTIR) spectra was taken, and the thermal degradation of the EPDM rubber was observed for varying amounts of vulcanising agent and filler content. Although the vulcanising agent improved the mechanical properties of the EPDM initially, a further increase in the vulcanising agents deteriorated the mechanical properties. Attenuated total reflectance FTIR spectrum confirmed the decrease in the relative degree of cross-linking with the increase in the vulcanising agent content to 10 h−1. Moreover, attenuated total reflectance FTIR spectra reaffirmed that cross-linking density increases with carbon black content. In situ FTIR spectra showed that the thermo-oxidative stability increased with the increase in filler content.

Effects of Malienated Ethylene Propylene Diene Monomer (EPDM) Rubber on Dynamic-Mechanical and Rheological Properties of Polyamide 66 (PA 66) Composites

Reactive blends of ethylene propylene diene monomer (EPDM) and polyamide (PA) 66 were prepared in the single screw and twin screw extruder using maleic anhydride as coupling agent and dicumyl peroxide (DCP) as initiator. The optimum concentration of DCP for grafting maleic anhydride on EPDM was determined. The grafting efficiency was determined by Fourier transform infrared (FTIR) spectroscopy, and (DMTA) tests were conducted to determine the damping, loss, and storage modulus of PA 66 composites. A capillary rheometer and parallel plate rheometer were employed to characterize the rheological properties at high and low shear rates. It was seen that the glass fibers are not long and continuous, and they act as fillers, therefore reducing the damping in the composite. No significant change was observed in the glass transition temperature of the blend as compared with the individual components, especially PA 66. In malienated EPDM blends with increasing EPDM from 10 to 15%, the height of glass transition temperature peak increases. Capillary rheometer tests show that for all samples the apparent viscosity decreases with increasing shear rate, which is a characteristic of a non-Newtonian pseudo plastic fluid. The viscosity ration of malienated EPDM and PA 66 shows a considerable difference between them and only at higher shear rates do the viscosities get closer.