Ethylene Propylene Diene Elastomer Research Articles

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

Experimental investigation on mechanical and microstructural behaviour of GFRP elastomeric nanocomposites

In many industrial applications elastomers are frequently used due to its low cost. In present study the Ethylene propylene diene elastomer (EPDM) was used. Solution intercalation method adopted to synthesize EPDM/OMMT clay nanocomposites using organically modified montmrillonite clay. At different loading levels of clay (2%, 3% and 5% weight) various characterizations such as tensile strength, flexural strength and d-spacing behaviour were performed. X-ray diffraction technique was used to study the d-spacing behaviour of different nanocomposites at 2%, 3% and 5% weight percentage of clay loading level. Clay dispersion in the rubber matrix was observed by scanning electron microscope. Comparative study between pure EPDM specimen and EPDM clay nanocomposite specimen was carried out. Modulus as well as flexural strength value was higher for EPDM clay specimen as compared to pure EPDM specimen.

Study of the Structure and Elastic Properties of Ethylene‒Propylene‒Diene Elastomers by Atomic Force Microscopy

Study of the Structure and Elastic Properties of Ethylene‒Propylene‒Diene Elastomers by Atomic Force Microscopy

Topological, Micromolecular, and Supramolecular Structure of Ethylene-Propylenediene Elastomers and Patterns of their Combination with Nitrile Butadiene Rubbers

Topological, Micromolecular, and Supramolecular Structure of Ethylene-Propylenediene Elastomers and Patterns of their Combination with Nitrile Butadiene Rubbers

Study on supercritical CO2‐assisted modification of aramid pulp and properties of its reinforced EPDM composites

AbstractAramid pulp (AP) is often used as a composite reinforcement due to its excellent properties, but poor dispersion and interfacial adhesion restrict its application in composite materials. In this work, tetraethyl orthosilicate (TEOS) was carried on the surface of AP by supercritical CO2 (scCO2) and hydrolyzed to synthesize the nano‐silica, which improves the dispersion of AP in ethylene‐propylene‐diene elastomer (EPDM). The nano‐silica particles were deposited on the AP surface, and th modified AP was evenly dispersed in the EPDM composites based on the SEM results. Moreover, a silane coupling agent (KH‐560) was brought by scCO2 to further modify the nano‐silica on the surface of the AP to improve the interfacial adhesion. Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy results show that after KH‐560 modification, active epoxy groups were introduced on the surface of AP. The tensile strength and tear strength of the KH‐560‐nano‐silica‐AP/EPDM composites were significantly improved, reaching 8.98 and 42.06 MPa, which increased by 26% and 88.10%, respectively, compared with untreated‐AP/EPDM composites. Dynamic mechanical analysis shows that the storage modulus of KH‐560‐nano‐silica‐AP/EPDM composites increased to 2456 MPa compared with the pure EPDM for 1873 MPa, and the loss factor decreased. When the AP was modified in scCO2 with nano‐silica and KH‐560, the composites' oil resistance was also improved.

Effects of different supercritical temperatures on the modification of aramid pulp surface via coating silica to enhance the properties of EPDM composites

AbstractPoor dispersion is a major disadvantage of aramid pulp (AP) reinforced composites. In this study, nano‐silica (SiO2), as the surface modifier and reinforcing agent, was synthesized on AP surfaces to improve the dispersed character in ethylene‐propylene‐diene elastomer (EPDM) using supercritical carbon dioxide (scCO2). The influence of the temperature of scCO2 on treated AP, configuration of the surface, and mechanical performance of AP/EPDM composites were studied. Based on the results of Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy, SiO2 was chemically grafted onto the AP surface. The SiO2 nanoparticles were uniformly deposited on the AP surface, and the roughness of AP was increased based on the SEM results. The optimum temperature of the supercritical reaction was 100°C considering the results of all the tests. Under the optimum temperature and with 10 phr of AP, the mechanical properties, oil resistance, and dynamic mechanical properties of the SiO2‐AP/EPDM composites were investigated. The tensile strength and tear strength of the SiO2‐AP/EPDM were improved by 121.1 and 134.9%, respectively, compared with that of the pure AP/EPDM composites. The fracture surface of the SiO2‐AP/EPDM composites showed that SiO2‐modified AP had a good dispersion in EPDM, and AP and EPDM had good interfacial bonding. Dynamic mechanical analysis results showed that the storage modulus of the composites was improved greatly compared with the pure AP/EPDM, and the loss factor also increased. The oil resistance of the composites was also improved.

Effect of SILPs on the Vulcanization and Properties of Ethylene-Propylene-Diene Elastomer.

Ionic liquids (ILs) are increasingly used in elastomer technology due to unique physico-chemical properties, which are stable at the temperature of preparation and during processing of rubber compounds. The latest IL application concept is supported ionic liquid-phase (SILP) materials, where an IL film is immobilized on the solid phase. The main aim of this work was studying the influence of IL immobilized on the surface of solid supports, such as silica and carbon black, on the vulcanization process, mechanical properties, and thermal behavior of ethylene–propylene–diene (EPDM) elastomer. Application of the SILP materials enabled the control of EPDM vulcanization without deterioration of the crosslink density, damping properties, thermal stability, and resistance of the vulcanizates to thermo-oxidative aging. Slight improvements in the tensile strength and hardness of the vulcanizates were observed.

Advances in Synthesis of Ethylene–Propylene–Diene Elastomers by Ion-Coordination Polymerization on Single-Site Catalytic Systems of New Generation

The studies devoted to the synthesis of ternary copolymers of ethylene, propylene, and nonconjugated cyclic dienes on single-site catalytic systems of a new generation based on metallocene complexes, “constrained geometry” complexes, and monocyclopentadienyl and post-metallocene chelate IVB-group complexes have been analyzed. The advantages and disadvantages of these catalytic systems have been compared with traditional vanadium catalysts introduced into production in the 1960s and used to date in the industrial synthesis of rubbers. A significant part of the review is devoted to the analysis of patent publications, especially in recent years, belonging to the main world producers of ethylene–propylene–diene rubbers.

Особенности радиотермолюминесценции композиций полипропилена и этиленпропилендиенового эластомера СКЭПT-4044 с наноразмерными металлосодержащими наполнителями

Using radiothermoluminescence (RTL), the molecular mobility features in the temperature range of 77-300 K were studied for the polypropylene (PP)/ethylene propylene diene elastomer SKEPT-4044 with NiO, Cu2O and Fe3O4 nanoparticles (NPs) based on ABS-acrylonitrile butadiene or SCS-divinyl styrene matrices. It has been shown that the introduction of nanofillers in PP significantly affects the nature and temperature of γ- and β-relaxation processes, while the region of manifestation of the β-process noticeably shifts to the region of low temperatures. Composites with Cu2O NPs have a higher β-transition temperature Tβ than composites with other NPs. It was found that PP/SKEPT-4044 composites with Cu2O NPs with a dispersion of 11-15 nm and acrylonitrile butadiene thermoplastics have optimal frost resistance compared to other compositions.

Problems of Controlling the Rheological Behavior of Thermoplastic Vulcanizates

Problems of the rheological behavior of thermoplastic vulcanizates prepared by dynamic vulcanization in the basis of polypropylene and the ternary ethylene–propylene–diene elastomer are considered. It has been shown that the nature of a vulcanizing system and the molecular structure of polypropylene are the most important factors influencing the rheological behavior of the studied materials. The use of an oil-extended elastomer enables the creation of processable blends containing up to 70 wt % of the rubber phase. The partial replacement of the elastomer by rubber powder leads to a decrease in the viscosity of the materials containing up to 50 wt % of the elastomer even without a plasticizer.

Modified ethylene‐propylene‐diene elastomer (EPDM)‐contained silicone rubber/ethylene‐propylene‐diene elastomer (EPDM) blends: Effect of composition and electron beam crosslinking on mechanical, heat shrinkability, electrical, and morphological properties

ABSTRACTIn this investigation, a gamma radiation‐induced methacrylic acid (MAA)‐grafted ethylene‐propylene‐diene elastomer (EPDM) was used as a third component (g‐EPDM) in silicone rubber (SiR)/ethylene‐propylene‐diene elastomer (EPDM) blends. These blends were electron beam (EB) crosslinked. The effect of blend composition, the presence of g‐EPDM, and EB crosslinking on the mechanical, heat shrinkability, electrical, and morphological properties of SiR/EPDM blends have been studied. To investigate the effect of grafted EPDM (g‐EPDM), 10 wt % of g‐EPDM was added to immiscible SiR/EPDM blends. Both silicone and EPDM are blended in different proportions (70:30 and 30:70) with and without g‐EPDM followed by compression molding. To improve the properties and investigate the crosslinkability of binary and ternary blends further, the SiR/EPDM blends were irradiated by electron beam at different doses (50, 100, and 150 kGy). The gel content was found to increase with EPDM content, the presence of g‐EPDM, and radiation dose. The addition of g‐EPDM led to improvement of tensile properties (tensile strength, Young's modulus, percentage elongation, and toughness), electrical properties, and shrinkability of blends. EB crosslinking further enhanced the above properties. Surface morphology (SEM) revealed that the presence of g‐EPDM and the incorporation of EB crosslinking improved the above properties of blends. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47787.

The Effect of Mixing Conditions on the Mechanical Properties of Polymer Mixtures of Low-Density Polyethylene and Rubber Powder Based on Ternary Ethylene–Propylene–Diene Elastomer

The effect of mixing conditions on the properties of polymer mixtures of low-density polyethylene with vulcanizates and rubber powder based on ternary ethylene–propylene–diene elastomer was studied. Polymers were mixed by two techniques: using a rotor disperser by high-temperature shift deformations and in a Brabender mixer. The analysis of mechanical characteristics of rubber plastics manufactured using different types of equipment showed that deformation and strength properties of rubber plastics mixed in a rotor disperser are higher compared to those made in a Brabender mixer.

Thermal analysis applied to studying the influence of ionic liquids on the vulcanization, thermal stability and damping properties of ethylene-propylene-diene rubber

The main aspect of the research was developing new systems for activating sulfur vulcanization of ethylene-propylene-diene elastomer (EPDM) with greater activity than the micrometer zinc oxide that is traditionally used. Differential scanning calorimetry (DSC) was applied to study the temperature and enthalpy of EPDM vulcanization. The range of vulcanization temperatures and the enthalpy of this process were determined. Thermogravimetric analysis was performed to characterize the effect of ILs on the thermal stability of vulcanizates. Dynamic mechanical analysis with tension deformation was used to study the influence of ILs on the loss factor (tan δ) of EPDM determined as a function of temperature, which is a measure of the ability of the material to dampen vibration. DSC results indicated that ILs significantly reduced the onset temperature and enthalpy of EPDM vulcanization. The most active were alkylimidazolium chlorides, which eliminated the post-curing process. Owing to lower decomposition temperature compared to EPDM, ILs decreased the thermal stability of vulcanizates. On the other hand, ILs had no significant influence on damping properties of EPDM in the rubbery elastic region. Vulcanizates containing ILs exhibited stable dynamic properties at the temperatures of use.

Quantification of Aerospace Polymer Blends by Thermogravimetric Analysis and Infrared Spectrometry

Ethylene-propylene-diene elastomer (EPDM) is employed as thermal insulation for rocket motors, as well as EPDM blends with ethylene vinyl acetate (EVA) have been used in the aerospace industry. The quantification of these blends is more common using Fourier Transform Infrared Spectrometry (FT-IR) by transmission mode, but without discussing sample preparation and methodology error. Considering this fact, a methodology was developed for determining EVA content in binary blend with EPDM samples, by Universal Attenuated Total Reflection (UATR) technique, associated to thermogravimetric analysis (TGA). This last one, it was applied to determine Vinyl Acetate (VA) content in EVA and to identify differences between EPDM/EVA blends. Samples of the analyzed blends showed two VA contents and five proportions of EPDM/EVA: 90/10, 70/30, 50/50, 30/70, and 10/90. The carbonyl stretching vibration band C=O at 1740 cm–1 was used as analytical band in FT-IR quantification. Finally, the results presented excellent accuracy with a good linear correlation coefficient (R > 0.940) and with relative error values lower than 2%, respecting the precision limits of the FT-IR spectrometer.

Identification of temperature scanning stress relaxation behaviors of new grade ethylene propylene diene elastomers

AbstractNatural rubber is the most common material for dynamic applications. Its limited service temperature leads to search alternative elastomeric materials for related areas. In this study, natural rubber, traditional ethylene propylene diene rubber (EPDM), and a new grade EPDM with modified structural properties have been evaluated by means of tensile properties, characteristic temperatures, cross‐link density, isothermal and nonisothermal relaxation behaviors with temperature scanning stress relaxation (TSSR) method. Linear molecular structure of the alternative EPDM elastomers provided improved tensile strength and isothermal stress relaxation behavior. Small amount of process oil addition also improved their service temperatures due to better processing conditions. Annealing study showed that strain‐induced crystallization is one of the important factors controlling service conditions of EPDM. Besides, TSSR technique was concluded to be a fast and powerful technique for measuring cross‐link density and for predicting service temperatures of natural rubber and EPDM elastomers.

Gamma radiation aging of EVA/EPDM blends: Effect of vinyl acetate (VA) content and radiation dose on the alteration in mechanical, thermal, and morphological behavior

ABSTRACTA series of ethylene vinyl acetate (EVA)/ethylene‐propylene diene elastomer (EPDM) blends (50/50 ratio) with four types of EVAs were prepared using brabender type batch mixer followed by compression molding. All compression‐molded samples were exposed to gamma radiation at 500, 1000, and 1500 kGy doses and were subjected to mechanical, compression set, thermal and morphological test. The % retention in tensile strength, elongation, and hardness were found higher for higher vinyl acetate (VA) containing radiation aged EVA/EPDM blends. The compression set value was decreased with increase of VA content. The thermal degradation kinetics of high VA containing irradiated blend (EVA40/EPDM) (EVA40 is 40%VA containing EVA) was found slower than those of lower VA containing blend (EVA18/EPDM). The surface morphology for EVA18/EPDM sample was transformed into more irregular one with more cracks and fragmented segments by aging at 1500 kGy dose while surface for EVA40/EPDM sample was found comparatively smooth, fine, and continuous with very few cracks and fragmented parts at similar dose. Thus, from the measured properties and morphology, it was revealed that the degree of degradation of blends kept on decreasing with increase in VA content. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46216.

The Effect of Metal-containing Nanofillers on the Properties of Blended and Dynamically Vulcanised Thermoplastic Elastomers Based on Isotactic Polypropylene and Ternary Ethylenepropylenediene Elastomer

New thermoplastic elastomers based on isotactic polypropylene and a ternary ethylenepropylenediene elastomer of different composition (with and without oil) with the use of nanofillers containing nanoparticles of oxides of different metals have been developed. It is shown that a small addition of nanofiller has practically no effect on the crystallinity and dielectric permittivity of the thermoplastic elastomers, but lowers their elastic modulus. The size of the nanoparticles has a considerable effect on the mechanical properties of the materials. The introduction of nanofillers into blends based on oil-extended elastomer does not affect their properties.

ENGAGE compatibilized HDPE/EPDM blends: Modification of some industrially pertinent properties and morphology upon incorporation of Mg(OH)2 filler and electron beam crosslinked network

ABSTRACTTo observe the effect of ENGAGE (a poly‐olefin elastomer) on compatibilization of industrially important incompatible blend, high‐density polyethylene (HDPE)/ethylene‐propylene diene elastomer (EPDM), 15 wt % ENGAGE is incorporated into the system and the latter is found satisfactorily efficient as compatibilizer for the above system. To improve some industrially pertinent properties another strategies are also followed in addition, incorporation of magnesium hydroxide [Mg(OH)2] and electron beam (EB) crosslinking into the system. The gel content was found to increase with radiation dose, EPDM content and Mg(OH)2 dispersion. ENGAGE interestingly increases the gel content that is, promotes crosslinking. It is unique that filler dispersion and crosslinked network formation maintain the compatibility of the ternary system, which is confirmed by X‐ray diffraction, differential scanning calorimetry, mechanical properties, and scanning electron microscope. The compatibilization, Mg(OH)2 dispersion, and EB crosslinking improve the mechanical, thermo mechanical, flame retardant properties, and phase morphology considerably. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44922.

РАЗРАБОТКА ПОЛИМЕРНЫХ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ НА ОСНОВЕ ТЕРМОПЛАСТИЧНЫХ ЭЛАСТОМЕРОВ

This paper presents data on the development of polymer composite materials based on thermoplastic elastomers. As starting materials for the synthesis of the matrix components were selected as follows: isotactic polypropylene and ternary ethylene-propylene-diene elastomer (EPDM). Diene component in EPDM are ethylidene norbornene composition in an amount of 4-5%. Dynamic vulcanization was carried out using the elastomer element sulfur. The filler polymer composite materials used silica gel with dimethyl polysiloxane. Synthesis was carried out by filling the sol-gel technology. The filler content in the composite varied from 10 to 80% by weight. Mixing of filler and the matrix was performed in a laboratory twin-rotor mixer, type "Brabender". It is found that the maximum possible filler content of the matrix used was 80%. With the introduction of more filler mixing of the components it has been difficult. When the filler content from 10 to 70% of parameters such as tensile strength, flexural strength and modulus of longitudinal elasticity increasing and administered at higher filler and 80 wt%. markedly reduced. Thus, it can be concluded that the content of filler in the composite is 70%. Further research should be directed to the evaluation of the radiation resistance of the developed composite materials.

The Effect of Paraffin Oil on the Structure of Vulcanisates of Ternary Ethylene Propylene Diene Elastomers

An investigation was made of the process of vulcanisation of ternary ethylene propylene diene elastomers (SKEPTs) with different contents of paraffin oil. Sol–gel analysis was carried out, and the crosslink density of the obtained vulcanisates was determined. The structure of the obtained vulcanisates was investigated using atomic force microscopy. It was shown that the process of vulcanising SKEPTs proceeds inhomogeneously within the specimen. There are both sparsely and densely crosslinked regions: darker unstructured zones are lightly crosslinked by comparison with the lighter regions. The presence of oil in the rubber promotes a more homogeneous crosslink distribution within the specimen.