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Ethylene propylene diene monomer (EPDM) is a synthetic rubber widely used in industry and commerce due to its high thermal and chemical resistance. Nanotechnology has enabled the incorporation of nanomaterials into polymeric matrixes that maintain their flexibility and conformation, allowing them to achieve properties previously unattainable, such as improved tensile and chemical resistance. In this work, we summarize the influence of different nanostructures on the mechanical, thermal, and electrical properties of EPDM-based materials to keep up with current research and support future research into synthetic rubber nanocomposites. [ABSTRACT FROM AUTHOR]

Oxidative aging is a significant deterioration process that affects the performance and durability of rubber materials in various applications. Therefore, this study focuses on the development of new antioxidants‐based on polyaniline for ethylene propylene diene monomer (EPDM) rubber to enhance its resistance to oxidative aging. The novel polyanilines were prepared using in situ polymerization method and characterized using Fourier transforms infrared (FTIR) and thermogravimetric analysis (TGA). FTIR illustrates the success synthesis of polyanilines as it shows their characteristic functional groups. The thermal stability of the formed polyanilines is discussed through TGA and derivative of thermogravimetry (DTG) curves. The curves prove the good thermal stability of the synthesized polymers. The prepared polyaniline compounds were mixed to carbon black filled‐EPDM rubber composites using a roll mill and then vulcanized using sulfur curing process. Accelerated aging tests for the prepared EPDM rubber composites were conducted to evaluate the effectiveness of the antioxidants. Moreover, their impact on rheometer, mechanical, and swelling properties was studied. The results showed that the EPDM samples with the prepared polyaniline compounds exhibited improved oxidative properties compared to the EPDM sample with commercial antioxidant 2,2,4‐trimethyl‐1,2‐dihydroquinoline. These findings suggest that the novel antioxidants have the potential to enhance the durability and performance of EPDM rubber in various applications. [ABSTRACT FROM AUTHOR]

The cross‐linked network and dynamic viscoelastic properties of ethylene propylene diene monomers (EPDMs)/polyamide elastomer (PAE) were systematically investigated by using equilibrium swelling test and rheological experiment. The filler network formed by single‐walled carbon nanotubes (SWCNTs) in the matrix of EPDM/PAE was studied and discussed in detail by virtue of scanning electron microscopy (SEM). The DIN abrasion test was conducted to derive the cross‐linked network dependence of the frictional wear performance of EPDM. The results indicated that the chemical cross‐linked network was contributed by EPDM and EPDM‐PAE macromolecular chains. In addition, the physical cross‐linked network consisted of the macromolecular entanglement of EPDM‐PAE and the interactions between EPDM/PAE and SWCNTs. Introducing PAE into EPDM matrix resulted in the change of the cross‐linked network, which was considered as the key factor to improve the abrasion resistance of EPDM. Furthermore, the physical cross‐linked network generated by PAE improved the strength of the EPDM matrix prominently. It is an innovative work in exploring the effect of microscopic structure on the macroscopic wear performance of EPDM vulcanizates. Highlights: Preparation of EPDM/PAE elastomer using new wear‐resistant material.Analysis on the effect of solubility parameters using Hansen solubility parameter (HSP).Flory–Huggins interaction parameter on three‐dimensional crosslink networks.Microscopic discussion on crosslink‐filling network structure.A new perspective on the discussion of wear resistance mechanism. [ABSTRACT FROM AUTHOR]

Two-component (2K) injection molding of the combination of recycled polypropylene (rPP) and ethylene propylene diene monomer (EPDM) is very promising for automotive industry. Recently, the use of post-industrial wastes in the automotive industry became important in terms of reducing its environmental impacts and circular economy principles. In this study, the effect of processing parameters on the properties of rPP/EPDM deflector parts fabricated by means of a 2K injection molding process was investigated. Post-industrial waste PP was used in varying amounts (0%, 10% and 20% by weight) in rPP/EPDM parts. The properties of aged and unaged rPP/EPDM deflector parts were then compared. The effects of processing parameters on dimensional, mechanical, thermal, and morphological properties of rPP/EPDM parts were investigated by a coordinate measuring device (CMM), scanning electron microscope (SEM), tensile test, and differential scanning calorimetry (DSC) analysis. As a result of the CMM analysis, it was seen that the dimensional stability of the unaged parts was better than the aged parts. The adhesion between rPP and EPDM was found to be dependent on injection temperatures. [ABSTRACT FROM AUTHOR]

To understand how the silyl-bridged metallocene catalysts rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2 behave against dienes under the same reaction condition because of its importance as a commercial polymerization catalyst and ethylene propylene diene monomers (EPDM). Adding diene depressed the catalytic activity, especially 5-ethylidene-2-norbornene (ENB) exerted the most substantial deactivation effect. Firstly, we examine the (ENB, vinyl norbornene (VNB) and 4-vinylcyclohexene (VCH)) non-conjugated and conjugated (isoprene (IP), butadiene (BD)) diene and address how polymerization catalysts behave against these dienes. For example, the catalytic activity was enhanced with IP and BD (3–3.3106 gm/mmolMt·h) compared to ENB, VNB and VCH. The VNB incorporation rate was prolonged (5.4 mol%), but with IP and BD, it was relatively moderate. E/P/IP and E/P/BD with higher incorporation of E produced a higher MW, which means that the chain transfer reaction with ethylene is slower than P. Secondly, we address how the dienes exocyclic and exocyclicπ bonds of non-conjugated and conjugated properties of IP and BD affect the kinetic measurements such as active centers [Zr]/[C*] fraction, EPDM chain propagation, termination, and isomerization. Finally, we compare [Zr]/[C*] and kpPE, kpP and kpDienes for different EPDM. After collecting these kinetic parameters, we can describe the mechanism's intricacy and the existence of considerable catalyst dormancy with dienes under identical reaction conditions. [ABSTRACT FROM AUTHOR]

Ethylene Propylene Diene Monomer (EPDM) rubber foams are widely employed for thermal and acoustic insulation in building construction. However, their installation in confined spaces is often complicated, and the capability of EPDM foams to exhibit shape memory behavior could be a desirable property. In the literature, several works have demonstrated that blending elastomeric matrices with paraffin, a well‐known Phase Change Material (PCM), could be an interesting method to obtain shape memory polymers with a tunable switching temperature. In this work, EPDM foams filled with paraffin wax, having a melting temperature of 70°C, were produced and characterized from a microstructural and thermo‐mechanical point of view. By melt compounding and hot pressing, samples were produced, and the PCM content in the foams was varied between 0 and 60 wt% (with respect to the EPDM matrix). The results of the shape memory tests evidenced the crucial role played by the PCM in providing excellent shape fixability for the expanded rubber. Even a limited amount of paraffin (i.e., 20 wt%) was able to raise the strain fixity parameter to a value higher than 80%, and it reached 100% when the paraffin content was increased to 60 wt%. On the other hand, an increased PCM fraction caused a slower recovery process. Consequently, a compromise between a fast recovery and optimum shape fixability should be accepted. These results are promising for the development of novel thermal and acoustic EPDM insulating foams easier to be installed. [ABSTRACT FROM AUTHOR]

Ethylene/propylene (E/P) and ethylene/propylene/5-ethylidene-2-norbornene (E/P/ENB) copolymers were obtained on rac-Et(2-MeInd)2ZrMe2 activated by a number of isobutylaluminium aryloxides: (2,6-tBu2PhO-)AliBu2 (1-DTBP) (2,6-tBu2,4-Me-PhO-)AliBu2 (1-BHT), (2,4,6-tBu2PhO-)AliBu2 (1-TTBP), (2,6-tBu2,4-Me-PhO-)2AliBu (2-BHT), (2,6-tBu2PhO-)2AliBu (2-DTBP), [(2-Me,6-tBu-C6H3O)AliBu2]2 (1-MTBP), [(2,6-Ph2-PhO)AliBu2]2 (1-DPP). This study shows how the structure of an activator influences catalytic activity and polymer properties, such as the copolymer composition, molecular weight characteristics, and thermophysical and mechanical properties. It has been shown that both the introduction of a bulky substituent in the para-position of the aryloxy group and the additional aryloxy group in the structure of an activator lead to a significant decrease in activity of the catalytic system in all studied copolymerization processes. Moreover, activation by bulkier aryloxides leads to lower levels of comonomer insertion and gives rise to higher molecular weight polymers. Broad or multiple endothermic peaks with different values of melting points are observed on the DSC curves of the copolymers obtained with different catalytic systems. The DSC of the thermally fractionated samples makes it possible to reveal the heterogeneity of the copolymer microstructure, which manifests itself in the presence of a set of lamellar crystallites of different thickness. The results also present the mechanical properties of the copolymers, such as the tensile strength (σ), elongation at break (ε), and engineering strain (EL). The synthesized E/P and E/P/ENB copolymers contain about 1–4 wt.% of the sterically hindered phenols obtained in situ as a residue of the hydrolyzed activators in the course of reaction quenching. This determines the increased thermooxidative stability of the copolymers. [ABSTRACT FROM AUTHOR]

The effect of the parameters of the suspension process for the production of EPDM synthetic ethylene-propylene rubbers, which leads to the production of rubbers with yields of more than 10 kg of rubber per 1 g of vanadium with physicochemical properties that correspond to the most popular grades of EPDM rubbers, was investigated. Ethylene, propylene, and ethylidenenorbornene or dicyclopentadiene were used as monomers. It was shown that realization of the suspension process in the presence of the catalytic system vanadium {2,4-ditertbutyl-6-[(tert-butylimino)methyl]phenolate}oxodichloride–ethyl trichloroacetate–diethylaluminum chloride leads to the production of EPDM rubbers with yields of 10000–23000 g/g of vanadium. The obtained grades of EPDM rubbers can be used in the automotive and construction industries, in the production of rubber products, sealants, adhesives, and as additives for technological fluids. [ABSTRACT FROM AUTHOR]

The effect of gamma‐irradiation on the ethylene propylene diene monomer (EPDM) based composites, loaded with tungsten and barium sulfate were investigated for radiation resistance properties. The tungsten and barium sulfate fillers were added in different proportion (wt%) to EPDM matrix and prepared using compression molding technique. The developed EPDM composites were exposed to 60Co gamma radiation doses from 0 to 400 kGy. The swelling index of the composites were studied for the irradiated samples and found to decrease with higher gamma doses. Tensile characterization was also carried out and elongation at break, tensile strength and modulus at 100% elongation have been determined for gamma irradiated EPDM based composites. Tensile properties were modified in the irradiated samples and elongation at break is decreased whereas the modulus increases as a function of gamma dose due to increases in crosslinking after irradiation. Thermogravimetric analysis was performed and observed improvement in thermal stability of gamma irradiated EPDM composites. [ABSTRACT FROM AUTHOR]

The mechanical properties of γ-irradiated ethylene propylene diene monomer (EPDM)/high styrene-butadiene rubber (HSBR) blends were investigated with special reference to the effects of blend ratio. Among the blends, the one with 80/20 EPDM/HSBR has been found to exhibit the highest tensile, hardness, thermal, and abrasion properties. The effect of γ-irradiation dose on the mechanical properties namely tensile strength and elongation at break was investigated. The effect of silane coupling agent on the mentioned properties of the EPDM/HSBR blend was studied. The results showed that the mechanical and the thermal properties of the γ-irradiated EPDM/HSBR blend improved with the addition of the silane coupling agent due to the increase in the cross-linking density. The inclusion of both the 30 phr fumed silica and N, N - m -phenylenedimaleimide coagent in the 80/20 EPDM/HSBR nanocomposite irradiated to 150 kGy leads to a synergistic effect. Thermogravimetric analysis was carried out to analyze the thermal stability of the nanocomposites. The mechanical properties have been interpreted in terms of the morphology of the blends as attested by scanning electron microscope. [ABSTRACT FROM AUTHOR]

In this study, the effects of plastic deformation and failure of the folded part on the folding behavior of non‐crosslinked ethylene propylene diene terpolymer/paraffin oil/silica gel composites were investigated. The folding behavior was evaluated by the residual fold angle of a folded specimen; a lower fold angle indicates an enhanced folding performance. The fold angle decreased with increasing oil and silica content and was correlated with the tensile yield strain, which is generally related to plastic deformation. Furthermore, the test speed dependence of the fold angle for each set of oil contents and test temperatures was investigated. The fold angle decreased with a decrease in the test speed and an increase in the test temperature. Scanning electron microscopy revealed that the low‐fold angle, which indicates an improvement in the folding behavior, was caused by the destruction (voids, crazes, and cracks) of the folded part. [ABSTRACT FROM AUTHOR]

Ethylene-propylene-diene rubbers (EPDM) are one of the most important polyolefin materials widely commercialized and used in various industries in recent years. The production of EPDM is based solely on catalytic coordination polymerization processes. The development of new catalysts and processes for the synthesis of EPDM has expanded the range of products and their manufacturing in terms of energy efficiency, processability, and environmental safety. This mini-review mainly analyzes patented data on the synthesis of EPDM on new-generation single-site catalytic systems based on Group IVB complexes including the systems commercialized by major manufacturers of EPDM. The advantages of these systems are evident in comparison with conventional vanadium systems introduced into production in the 1960s and used to date in the industrial synthesis of EPDM. [ABSTRACT FROM AUTHOR]

In this study, a partially reticulated foam was fabricated based on ethylene propylene diene monomer rubber to absorb low‐frequency acoustic waves. The effect of ethylene content was studied on the cellular structure, viscoelastic behavior, and sound abortion characteristics. High airflow resistivity of the developed partially reticulated structure, as well as highly deformable cell walls of EPDM foams, led to large dissipation of sound energy at low and medium frequencies. Samples with lower ethylene content which exhibited lower storage modulus and larger pore sizes showed higher viscose motions with superior sound absorption. The foam sample with the lowest ethylene content offered the best sound absorption coefficient with a sharp peak as high as 0.91 within the 500–2500 Hz frequency range. The results imply the role of ethylene content as a molecular structure tool to optimize the acoustic absorption potential of EPDM foam. Besides, the foam samples showed considerable insulation performance, yielding a sound reduction index equal to 26–29 dB. The absorption and reflection of the sound waves were integrated to provide the insulation. Thus, a developed lightweight insulator with high resistance to harsh environmental conditions and great low‐frequency sound absorption could be achieved by structural engineering. [ABSTRACT FROM AUTHOR]

This study, uses two polyfunctional monomers (PFMs) namely ethylene glycol dimethacrylate (EGDMA) as a bifunctional monomer and trimethylolpropane triacrylate (TMPTA) as a trifunctional monomer were used as co-agents in irradiation crosslinking of Ethylene Propylene Diene Monomer Rubber (EPDM). The effect of concentration of each PFM and irradiation dose on the crosslinking density, gel content, swelling behavior in motor and brake oils, in addition to the mechanical and thermal stability properties of EPDM was investigated in detailed. The results showed a remarkable increase in the gel content, crosslinking density and mechanical properties as the concentration of PFMs increased from 1 to 5 phr (parts per hundred parts of rubber). The various blends of EPDM with the trifunctional monomer express the highest gel content and crosslinking density than those with the bifunctional monomer. The addition of 5 phr of TMPTA to EPDM causes a dramatic improvement in tensile strength (TS) of the prepared blend reached to 188% compared to neat EPDM at 50 kGy. At the same time, the maximum TS of the blend containing 5 phr of EGDMA achieved only 41% compared to neat EPDM at an irradiation dose of 100 kGy. The swelling of irradiated samples in brake oil revealed a stronger oil resistance than motor oil. For all irradiated samples, the oil uptake decreased with the irradiation dose up to 100 kGy. The EPDM samples containing 5 phr of TMPTA recorded the highest oil resistance at 100 kGy. The results also showed that the addition of PFMs and irradiation treatment of the various prepared blends improved the thermal stability of EPDM. Finally, neat EPDM and the blends containing 1 and 3 phr of EGDMA can be used as radiation dosimeters in the very high dose range (50–200 kGy). [ABSTRACT FROM AUTHOR]

Two potential formulations of sulfur cured ethylene propylene diene terpolymer (EPDM) insulation were characterized against the proven insulation based on nitrile rubber (NBR) in the earlier study. Unlike the proven insulation, the cure behavior exhibited by sulfur cured EPDM is quite different in that, the rheometer curves exhibit marching behavior even at elevated temperature for longer duration (160°C for 7 h; most severe condition). This warranted extensive cure study at different temperatures for varying durations in order to determine the optimum cure condition. The methodology adopted to find out the optimum cure condition and corroboration of the same in terms of instrumental techniques (differential scanning calorimetry, thermogravimetric analysis, and Fourier transform infrared), which are quite interesting, are discussed in this article. [ABSTRACT FROM AUTHOR]

Ethylene-propylene-diene rubbers (EPDM) are one of the most important polyolefin materials widely commercialized and used in various industries in recent years. The production of EPDM is based solely on catalytic coordination polymerization processes. The development of new catalysts and processes for the synthesis of EPDM has expanded the range of products and their manufacturing in terms of energy efficiency, processability, and environmental safety. This mini-review mainly analyzes patented data on the synthesis of EPDM on new-generation single-site catalytic systems based on Group IVB complexes including the systems commercialized by major manufacturers of EPDM. The advantages of these systems are evident in comparison with conventional vanadium systems introduced into production in the 1960s and used to date in the industrial synthesis of EPDM.

Ethylene propylene diene monomer rubber is used as flexible thermal protection for rocket engines, as well as in blends with polychloroprene, which can be applied in the aeronautical sector, and with great potential in the defense sector. However, there is not a considerable number of studies considering both polymers as a blend. In general, elastomer content quantification in blends is done by more complex instrumental methods. When performed by Fourier transform-infrared spectroscopy, the conventional transmission mode is used, usually without including the developed methodology error. Therefore, the Fourier transform infrared spectroscopy (FT-IR) methodology is proposed using the universal attenuated total reflection mode, with sample treatment (pyrolysis) to determine polychloroprene content in the mixture with ethylene propylene diene monomer. In accordance with the infrared spectrometer precision limits and rubber blends studies data found in the literature, the methodology error analysis shows a value close to 2%. In addition, it has the advantage of being a less complex methodology. This actual study uses a simple FT-IR analytical tool, scarce, especially for the rubber research community, to determine the content of rubber minor phase within the major phase. It is valuable in weapons reverse engineering, aiming at the knowledge of new thermal protections. [ABSTRACT FROM AUTHOR]

Even though literature available on EPDM is abundant, the data on physical, mechanical, thermal, interface properties and ablative performance as specifically required for the design and acceptance of internal insulation of large Composite Rocket Motor Casing is scant in the plethora of literature available in the subject of EPDM insulation. This gave the impetus to take up this experimental work wherein most promising formulation of EPDM with Kevlar and silica as reinforcing fillers and with only silica as reinforcing filler were thoroughly characterized for the insulation requirements of large Composite Rocket Motor Casing and compared with the performance of proven Nitrile rubber based insulation. The significant findings which are unique, are discussed in this paper. [ABSTRACT FROM AUTHOR]

A grommet, made of ethylene propylene diene methylene (EPDM) rubber, is an integral part used for fixing and protecting the wire inserted from the outside to the inside of vehicles. Rubber compounds exhibit various mechanical properties and vulcanization characteristics depending on the accelerator mixing ratio. These mechanical properties affect the insertion and detachment forces when the grommet is manufactured and fixed to the vehicle body. In this study, we experimentally analyzed the changes in the properties of EPDM rubber depending on the vulcanization accelerator to improve the mounting performance of the grommet, and subsequently derived the optimum accelerator mixing ratio. We implemented a mixture design strategy to derive the optimum mixing ratio for obtaining the desired mechanical properties and vulcanization characteristics. The insertion and separation forces of the existing grommet were compared with those of the grommet fabricated using the derived mixing ratio and we found that the mounting performance was improved compared to the existing grommet. [ABSTRACT FROM AUTHOR]

The effect of incorporating sorbic acid (SA), an echo-friendly curing agent, and silica or carbon black (CB) filler, as well as gamma irradiation on the physico-chemical, mechanical and thermal properties of ethylene propylene diene monomer rubber (EPDM) was investigated. The results indicated that the developed composites revealed improvement in the studied parameters over the untreated samples. Filler incorporation into rubber matrix has been proven a key factor in enhancing the swelling resistance, tensile strength and thermal properties of the fabricated composites. The improvement in tensile strength and modulus was attributed to better interfacial bonding via SA. Alternatively, a comparison was established between the performance of the white and black fillers. The utmost mechanical performance was reported for the incorporated ratios 10 phr SA and 40 phr white filler into a 50 kGy irradiated composite. Meanwhile, the incorporation of CB yielded better thermally stable composites than those filled with silica at similar conditions. [ABSTRACT FROM AUTHOR]

Natural Rubber (NR) has been used in dynamic applications for many years. NR has satisfactory resilience, vibration, and fatigue properties. Besides all these good properties, NR has quite poor aging resistance; also its service temperature is limited to about 90 °C. Improving aging characteristics of NR is a common problem for both rubber industry and academy. Nowadays, especially automotive industry has been focused on thermally resistant static and dynamic rubber based materials in new generation automobiles because of current strict emission regulations. There are a lot of attempts to improve service conditions of NR however; they are not comparable yet, with alternative saturated rubbers such as ethylene propylene diene monomer rubber (EPDM). In this study, a new grade EPDM, which had a high molecular weight, narrow molecular weight distribution, and tailor-made chain structure, has been studied in terms of rheological, mechanical, dynamic mechanical, aging, and low temperature properties for target dynamic applications. Especially possible service temperature and dynamic performance of EPDM were compared to that of NR based reference. It was concluded that, EPDM may be an assertive competitor to NR, if its chain structure is modified correctly. [ABSTRACT FROM AUTHOR]

• The ceramizable insulation can be converted into SiC structure in situ. • VHPCS can effectively improve the interface performance between AF and EPDM. • VHPCS-coated aramid fibers can increase the content of SiC. As a type of filler with excellent performance, fibers can effectively enhance the mechanical properties and ablation resistance of the EPDM insulation layer inside a solid rocket motor. However, an excessive amount of short-cut fibers can reduce the mechanical performance of the insulation layer. Therefore, in this work, a novel EPDM insulation material was reinforced by aramid fiber (AF) coated with liquid hyperbranched polycarbosilane (VHPCS) to improve the mechanical properties and ablation resistance of obtained composites by enhancing the interfacial properties between EPDM and AF as well as protecting the AF framework by in-situ transformation into a ceramic structure during ablation. The test results demonstrated a significant improvement in the ablation performance of the AF insulation materials coated with VHPCS. The linear ablation rate and mass ablation rate decreased by 22.67 and 11.67%, respectively. Furthermore, compared with the composites without VHPCS, the elongation at break was improved while maintaining the original tensile strength (60.60%). XRD and XPS analysis confirmed the presence of SiC formation in the carbon layer during ablation. Thermal analysis indicated that VHPCS increased the mass residual rate of the EPDM composites. Coating AF with VHPCS-modified EPDM increased the content of SiC structures on the carbon layer surface, effectively protecting the carbon layer structure and enhancing the ablation performance of the ceramicizable insulation. [ABSTRACT FROM AUTHOR]

Ethylene propylene diene polymethylene (EPDM) rubber is one of the fastest growing synthetic rubbers in the market. It is widely used in many fields due to its easy processing and high resistance against outdoor conditions compared to other rubber types. However, like all organic compounds, over time it is degraded under weathering conditions such as radiation, heat, ozone and chemical media, all of which can contribute to loss of bulk properties and reduce its service life. Cracks, discoloration, breakage, or staining can occur on the surface of visible automotive profiles due to the effect of UV light. These phenomena are definitely undesirable. In this study, five different EPDM rubber compounds (control and four different Flamestab® NOR 116 concentrations) were produced. The effects of the Flamestab NOR 116 were investigated by mechanical and rheological tests and ageing using the internationally recognised Florida artificial weathering test. The aged surfaces were visually scrutinised and surface morphological changes were examined via scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analyses. The results obtained showed that Flamestab® NOR 116 can be used as a UV stabiliser for EPDM rubber applications if it is added in amounts of between 1.25 and 2.0 phr. [ABSTRACT FROM AUTHOR]

Sorbic acid (SA) is available in the market for low-cost and eco-friendly. It is known for using as a preservative. SA was used as a modifier together with gamma radiation to improve the properties of ethylene propylene diene monomer rubber (EPDM). The effect of SA concentration and gamma irradiation dose on the mechanical and physico-chemical properties of EPDM was investigated. The results indicated that the properties of EPDM rubber blended with SA were improved compared to untreated EPDM sample. The highest improvement was achieved by using SA concentrations of 10 phr (part per hundred part of rubber) a dose of 100 kGy of gamma irradiation. These findings were demonstrated by scanning electron microscopy (SEM), x-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). [ABSTRACT FROM PUBLISHER]

Blends of ethylene-propylene diene terpolymer/acrylonitrile butadiene copolymer (EPDM/NBR) loaded with different types [(N326-HAF) and (N774-SRF)] and ratios of carbon black (CB) fillers were prepared. The mechanical properties of the EPDM/NBR rubber blends unloaded and loaded with different ratios of CB were investigated. Among the blends, the one with 75% EPDM and 25% NBR, both loaded and unloaded with CB, were found to exhibit the highest tensile strength and elongation at break. The observed changes in the mechanical properties of the blends were correlated to the morphology as observed by scanning electron microscopy. The changes of the electrical resistivity of the rubber blend composites during compression were investigated. The experimental results were explained from the position that an external pressure induces either an increase or decrease of the resistivity of the blend composites according to whether annihilation or creation of effective conductive paths occurs, respectively. [ABSTRACT FROM AUTHOR]

In this paper the influence of micro-sized (3 μm) and nano-sized (10 nm) silica (SiO2) on mechanical, thermal, and electrical properties of silicon rubber (SiR), epoxy, and ethylene propylene diene monomer (EPDM) composites is presented. The micro- and nano-sized SiO2 particle-filled SiR, epoxy, and EPDM composites were formulated with 20% microsilica and 5% nanosilica by weight respectively. Among these composites, SiR-SiO2 amalgamation was performed by mixing using an ultrasonication procedure. Epoxy-SiO2 was compounded in two steps, i.e. dispersion of fillers and mixing, whereas EPDM-SiO2 compounding was performed with a two roll mill technique. With the addition of micro/nano-SiO2, the composites showed enhanced tensile strength of ~ 2.7 MPa, improved hardness, and reduced elongation at break. Further incorporation of micro/nano-sized particles resulted in high thermal stability for SiRnano composites (SNCs) as compared to epoxy and EPDM composites. Compared to SiR and EPDM composites, epoxy-nano composites showed the highest value of dielectric strength, i.e. 38.8 kV/mm. Meanwhile, the volume and surface resistivity of SNCs were found higher as compared to other investigated samples. Promising properties of SiR nanocomposites among all the investigated samples suggest that their application is more suitable for utilization in outdoor electrical insulations. [ABSTRACT FROM AUTHOR]

Calcium carbonate/Bentonite filled Ethylene Propylene (EPDM) composites were prepared via two roll mill. The study focused on the effect of substituting the use of calcium carbonate with Bt on their curing characteristics and tear properties at different ratio loading of CaCO3/Bt (i.e. 30/0, 25/5, 15/15, 5/25 and 0/30). The results found that with decreasing CaCO3 loading in ratio loading of CaCO3/Bt, the optimum curing time, scorch time and maximum torque decreased and minimum torque increased. While, the tear strength of EPDM/CaCO3/Bt clay rubber composite was gradually increased as the CaCO3 loading in ratio of CaCO3 to Bt decreased. EPDM composite filled with Bt gave better reinforcement compared to EPDM filled with CaCO3 at the same loading. Scanning electron microscopy showed that the partial replacement of CaCO3 with Bt improved rubber-filler interaction and consequently increased the tear properties. [ABSTRACT FROM AUTHOR]

The oxidation process induced in ethylene-propylene-diene (EPDM) copolymer by gamma irradiation was simulated by solving equations on chemical reactions and gas diffusion rates. As a result, distributions of oxidative products and gases and changes in material properties were clarified. All the oxidative products such as ketones, alcohols, and carboxylic acids, crosslinks between molecular chains, and chain scissions in EPDM increase with irradiation and they show concave spatial distributions inside the sample sheets. The simulation results demonstrates that EPDM becomes hard when it was irradiated by gamma rays and the increase in hardness is more significant at the surface of the sample sheet than its inside. Moreover, it was found that a low diffusion coefficient of oxygen in EPDM leads to the appearance of a clearer diffusion-limited regime of degradation. These simulation results are in good agreement with experimental results. [ABSTRACT FROM PUBLISHER]

Ethylene-propylene-diene monomer (EPDM) rubber used as power cables insulation was exposed to a thermal aging in oven for different temperatures ranging from 80 to 140 ?C. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were carried out to identify the main structure changes of the material before and after thermal aging. It is found that for pristine EPDM specimens and those subjected to thermal aging at 80 and 100 ?C, there was no influence of these aging temperatures on the chemical structure of the material. On the other hand, an increase in oxidation with exposure time was observed for high temperatures (120 and 140 ?C). Oxygenated species such as C?O? C, C=O and O?C=O groups were formed. The DSC analysis shows that the crystallinity of the EPDM remains very low. The thermal stability of EPDM, assessed by TGA, showed that although volatile gases migrated from the sample, the studied EPDM keeps high thermal stability. Note that thermal aging effect is not very significant on the material bulk while it is accentuated on its surface. Quantitatively, the carbonyl index was determined since the carbonyl groups are usually the most oxidation products on thermooxidative degradation of cross-linked EPDM. [ABSTRACT FROM AUTHOR]

This paper is aimed at the characteristics of treeing phenomena developing in EPDM (Ethylene Propylene Diene Monomer) in a point ? plane electrode arrangement and the resulting damages when subjected to ageing AC voltage. It reports mainly on the measurements of the partial discharge inception voltage (PDIV) and partial discharges (PDs) accompanying the evolution of tree structures, the dissipation factor (tg?) and capacitor (Cx) of insulation as well as the chemical analyses that are Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) to identify the changes in the morphology and microstructure of damaged polymer. The obtained results evidence the fact that the tree formation is linked to the appearance of partial discharges which are promoted by off-gases forwards to the material microstructure modification. [ABSTRACT FROM AUTHOR]

Dynamic mechanical experiments performed on ethylene–propylene–diene (EPDM) terpolymer, cross linked to different extents, evidenced three relaxation processes. Besides the glass transition (Tg) and the melting of the ethylene crystals formed in the ethylene-based EPDM, a new transition appeared at a temperature higher than the glass transition temperature (so-called tan δgh) and decreased dramatically in amplitude with increase in the degree of cure. The new transition (tan δgh) was also above the melting point. The viscoelastic properties of the rubber with various crosslinking degrees are described. Based on the behavior of tan δghand the curing properties of EPDM, the tan δghpeak is primarily attributed to the motion of non-elastic network chains loosely attached to the three-dimensional network, including free chains. [ABSTRACT FROM AUTHOR]

Abstract: The thermal degradation kinetics of several ethylene–propylene copolymers (EPM) and ethylene–propylene–diene terpolymers (EPDM), with different chemical compositions, have been studied by means of the combined kinetic analysis. Until now, attempts to establish the kinetic model for the process have been unsuccessful and previous reports suggest that a model other than a conventional nth order might be responsible. Here, a random scission kinetic model, based on the breakage and evaporation of cleavaged fragments, is found to describe the degradation of all compositions studied. The suitability of the kinetic parameters resulting from the analysis has been asserted by successfully reconstructing the experimental curves. Additionally, it has been shown that the activation energy for the pyrolysis of the EPM copolymers decreases by increasing the propylene content. An explanation for this behavior is given. A low dependence of the EPDM chemical composition on the activation energy for the pyrolysis has been reported, although the thermal stability is influenced by the composition of the diene used. [Copyright &y& Elsevier]

Abstract: The stabilization of ethylene-propylene diene rubber (EPDM) with naringenin and caffeic acid is studied. The selected concentrations were 0.25, 0.50 and 1phr. The degradation was performed by γ–irradiation. The protective effect of these antioxidants was investigated by isothermal chemiluminescence at 170°C and FTIR spectroscopy. The synergetic action of these compounds and metallic selenium was also revealed. The exceptional contribution provided by these phenolic stabilizers is characterized by three kinetic parameters: initial CL intensity, oxidation induction time and maximum period of degradation. The radiation stability of stabilized EPDM is efficiently depicted by induction periods which are the minimum 6times longer for unirradiated samples and 2–50 times longer for 50kGy-irradiated specimens than pristineEPDM. [Copyright &y& Elsevier]

Abstract: In this study, changes in the properties of ethylene propylene diene terpolymer (EPDM) irradiated with different dose rates in ambient atmosphere and aqueous environment were investigated. Irradiations were carried out both with low dose and high dose rate irradiation sources. EPDM samples which were differentiated from each other by peroxide type and 5-ethylidene 2-norbornene (ENB) contents were used. Long term low dose rate irradiations were carried out for the duration of up to 2.5 years (total dose of 1178kGy) in two different irradiation environments. Dose rates (both high and low), irradiation environments (in aquatic and open to atmosphere), and peroxide types (aliphatic or aromatic) were the parameters studied. Characterization of irradiated EPDM samples were performed by hardness, compression, tensile, dynamic mechanical analysis (DMA), TGA–FTIR, ATR-FTIR, XRD and SEM tests. It was observed that the irradiation in water environment led to a lower degree of degradation when compared to that of irradiation open to atmosphere for the same irradiation dose. In addition, irradiation environment, peroxide type and dose rate had effects on the extent of change in the properties of EPDM. It was observed that EPDM is relatively radiation resistant and a candidate polymer for usage in radioactive waste management. [Copyright &y& Elsevier]

Abstract: In this study, waste tire dust is recycled as filler and blended with ethylene-propylene diene monomer (EPDM) rubber. Three different polyfuntional monomers (PFMs) are incorporated into the standard formulation and irradiated under electron beam at different doses up to maximum of 100kGy. The combined effects of PFMs and absorbed dose on the physical properties of EPDM/WTD blend are measured and compared with sulfur crosslinked formulation. Thermogravimetric analysis showed that radiation developed better crosslinked network with higher thermal stability than sulfur crosslinked structure. The physical properties of radiation crosslinked blend are similar to the sulfur crosslinked blend. The absence of toxic chemicals/additives in radiation crosslinked blends made them an ideal candidate for many applications such as roof sealing sheets, water retention pond, playground mat, sealing profile for windows etc. [Copyright &y& Elsevier]

Abstract: Properties of ethylene–propylene copolymer (EPM) are determined by ethylene/propylene ratio and degree of block and random sequences. EPM was pyrolyzed and the pyrolysis products were analyzed using gas chromatography/mass spectrometry (GC/MS) to examine pyrolysis products formed from the ethylene–propylene heterosequences. Pyrolysis products formed from EPM were compared with those formed from polyethylene (PE) and polypropylene (PP) to determine the pyrolysis products formed from ethylene–propylene heterosequences of EPM. Principal pyrolysis products formed from ethylene–propylene heterosequences were 3-methyl-1-hexene, 4-methyl-1-hexene, 2-methyl-1-hexene, and 2-heptene. Order of the relative intensity of the pyrolysis products was 2-methyl-1-hexene>4-methyl-1-hexene>3-methyl-1-hexene>2-heptene. The relative abundances of the pyrolysis products decreased as the pyrolysis temperature increased. Relative abundances of the specific pyrolysis products formed from ethylene–propylene heterosequences may be used for determination of the relative degree of random sequences of EPM as well as ethylene–propylene–diene terpolymer (EPDM). [Copyright &y& Elsevier]

Abstract: Ethylene-propylene-diene terpolymer (EPDM) having 5-ethylidene-2-norbornene (ENB) as a diene unit was pyrolyzed and the pyrolysis products were analyzed using gas chromatography/mass spectrometry (GC/MS) to develop a method for identification and quantitation of ENB. Pyrolysis products formed from ENB units were determined by comparing pyrolysis products of EPDMs with different ENB contents. Principal pyrolysis products generated from ENB units were benzene, toluene and 4-ethylidene-1-cyclopentene. Relative peak intensities of benzene and toluene increased as the pyrolysis temperature increased, whereas that of 4-ethylidene-1-cyclopentene decreased. The differences in peak intensity ratios of the ENB-derived pyrolysis products/propylene between EPDM and EPM (ENB content = 0 wt%) linearly increased as the ENB content of EPDM increased. ENB content in EPDM can be determined using the linear relationship between the difference in the peak intensity ratios and the ENB content. [Copyright &y& Elsevier]

Abstract: Saturated olefinic rubbers have been widely used as materials for not only municipal waterworks, but also for household uses. As a sanitizing agent for water, chlorine will be replaced by ozone in the near future from an environmental point of view. However, the ozone treatment in water seriously damages saturated olefinic rubbers, which are necessary for the infrastructure of daily life. Here, we report the surface degradation of cross-linked poly(ethylene-co-propylene-co-5-ethylidene-2-norbornene) terpolymer (EPDM) by ozone treatment, both in water and air. We also discuss how the presence of water impacts the ozone oxidation of EPDM, resulting in macroscopic damage to EPDM. [Copyright &y& Elsevier]

Abstract: Degradation of ethylene-propylene-diene (EPDM) rubber seal used for supplying water system was investigated through spectroscopic techniques. The EPDM seal was utilized at 20–45 °C for about 3 years. It was characterized by solid state nuclear magnetic resonance spectroscopy equipped with field gradient fast magic angle spinning probe and Fourier transform-infrared spectroscopy. Morphology of the EPDM seal was observed by scanning electron microscopy, focused ion beam scanning electron microscopy and electron probe micro-analysis. The hardness and crosslink density of EPDM seal were reduced by a factor of one-half after using for supplying water system, even though it contains little amount of carbon–carbon double bond. Surface of the EPDM seal was significantly damaged by water. The degradation of EPDM seal was associated with chain scission and oxidation of EPDM. [Copyright &y& Elsevier]

Blends of ethylene propylene diene monomer rubber (EPDM) and chlorinated isobutylene isoprene rubber (chlorobutyl, CIIR) with a reactive phenolic resin as the curing agent have been prepared through conventional two-roll mill mixing. The effect of resin curing on the mechanical properties of EPDM/CIIR blends was investigated and compared with conventional curing systems. The morphology of the blends as well as their thermal and steam aging resistance has also been reported. It was found that blends with a phenolic curing system exhibited superior mechanical and thermal aging properties and have potential applications in high-temperature engineered products. [ABSTRACT FROM AUTHOR]

A recurrent concern in the design of packaging for the transportation of radioactive material is to determine the life of elastomeric O-rings at a high temperature. Following a precedent paper presenting the TN International method for the determination of ethylene propylene diene (EPDM) O-rings seal life, a first series of tests results have been obtained. These first results are used with the previously mentioned method to see that the EPDM seal life did follow an Arrhenius curve. This Arrhenian behaviour is verified below a certain 'threshold temperature' that seems to be the upper limit for the use of such elastomeric O-ring grades. With the 'seal life versus temperature' curve obtained from these tests results, the time–temperature profile of O-rings in casks can then be benchmarked with the seal resistance and its 'maximum permissible damage rate'. [ABSTRACT FROM AUTHOR]

Abstract: Ethylene propylene diene monomer (EPDM) rubber mixes containing different types of bonding materials and various commercial antioxidants were used to evaluate the adhesion of EPDM rubber to polyester fabric. A new antioxidant was prepared by graft copolymerization of 1, 5-diaminonaphthalene (DAN) onto natural rubber (NR) in order to investigate its effect on adhesion. It was observed that EPDM mixes containing DAN grafted onto NR shows better adhesion levels than those containing commercial antioxidants. It is also clear that the new system has high resistance towards aging and ionizing radiation. The new NR-g-DAN acts not only to stabilize the rubber mix towards environmental conditions but also to improve adhesion to polyester fabric. [Copyright &y& Elsevier]

Abstract: Low infrared emissivity coating was prepared by the copper (Cu) particles and ethylene–propylene–diene monomer (EPDM) binder. The effect of size, shape and floatage of Cu particles on infrared emissivity of the coatings was systematically investigated. The results indicated that the optimized Cu particles with the minimum coating emissivity are several micron-sized, flaky and high-leafing, exhibiting 0.78, 0.72 and 0.10 emissivity value, respectively. The formation of low infrared emissivity coatings depends strongly on the floatage of Cu particles, not the size or shape, and the results obtained by leafing aluminum (Al) and bismuth oxide (Bi2O3) pigment are in good agreement with this standpoint. A theoretical model was proposed to account for the mechanism, which indicated that the low porosity of the coatings with leafing pigments plays an important role in the formation of low emissivity coatings. [Copyright &y& Elsevier]

Abstract: Radicals formed by irradiation by high energy electron in ethylene–propylene–hexadiene terpolymer (EP–HD) have been studied using electron spin resonance (ESR). Two methods were used to analyse the different radicals formed by irradiation: firstly, classical low temperature irradiations were carried out, secondly, rapid quenching in liquid nitrogen of the material after high dose rate irradiation. The feasibility and the efficiency of the latter method to observe short-lived radicals have been demonstrated. This type of experiment provides unique information concerning the rate of production and the rate of reaction of radicals. [Copyright &y& Elsevier]

Comparative studies on the effect of aluminium particles in natural rubber (NR) and ethylene-propylene-diene terpolymer (EPDM) were conducted. The incorporation of aluminium particles in NR or EPDM composites increased the cure time, t90, and scorch time, tS2. At a fixed filler loading, EPDM composites exhibited longer t90 and tS2 than NR composites. The results also indicate that the maximum torque, MH of aluminium filled NR and EPDM composites increase with increasing filler loading. For tensile properties, EPDM composites show lower tensile properties than NR composites. Thermogravimetric analysis (TGA) results show that aluminium filled EPDM composites have better thermal stability than aluminium filled NR composites. The results for electrical properties indicate that the electrical properties of aluminium filled NR and EPDM composites increase with increase in filler loading. [ABSTRACT FROM AUTHOR]

The melt viscoelastic properties of polypropylene (PP)/ethylene-propylene-lene monomer copolymer (EPDM)/glass bead (GB) ternary composites were measured in a wide scope of shear rates by using a Rosand capillary rheometer, to indentify the effects of shear stress, particle content and its surface treatment on the melt viscoelastic behavior during extrusion of the composites. The apparent shear rates varied from 10 to 105; s-l;, and the test temperature was 190°C. The results showed that the entry pressure drop (ΔPen;) and the melt extension viscosity (ηe;) increased with an increase of shear stress (τw;), and both the ΔPen; and ηe; were roughly an exponent function of τw; respectively. The influence of the bead surface treatment on the ΔPen; and ηe; is insignificant. The die-swell ratio (Β) of the melts increased roughly linearly with an increases of τw;, while decreased approximately nonlinearly with an addition of the GB volume fraction. The values of Β of the composite system for the EPDM grafted with maleic anhydride were somewhat more than those of the other composite systems under the same test conditions, especially at lower glass bead concentration. [ABSTRACT FROM AUTHOR]

Polymeric hindered amine light stabilizer (HALS), wherein the hindered amine functionality was attached to the brominated ethylene-propylene-diene terpolymer (EPDM) was synthesized. The brominated EPDM was synthesized as an intermediate for the synthesis of a new polymeric hindered amine light stabilizer. The grafting and functionalization reactions were characterized by FTIR and 1HNMR spectroscopy. The photostabilizing efficiency of this polymeric HALS was studied and compared with conventional HALS under accelerated weathering conditions. The results of the study give evidence for superiority of polymeric HALS over that of melt blended conventional HALS. [ABSTRACT FROM AUTHOR]

Abstract: The ageing of filled and cross-linked ethylene propylene diene elastomer (EPDM) has been studied under accelerated UV irradiation (λ ≥290nm) at 60°C, thermal ageing at 100°C and in nitric acid vapours for different time intervals. Hardness measurements were performed. DSC-thermoporosimetry was used to estimate the mesh size distribution and cross-linking densities for each ageing. The development of functional groups was monitored by ATR spectroscopy. An increase in oxidation with exposure time after the different types of ageing was observed. The thermal stability of EPDM was assessed by TGA and evolved volatile gases were identified using FTIR spectroscopy. [Copyright &y& Elsevier]