Ethylene Propylene Diene Copolymer Research Articles

Superhydrophobic porous film for daytime radiative cooling

Passive daytime radiative cooling (PDRC) offers a sustainable way without additional energy input to cool objects by simultaneously reflecting sunlight and radiating heat through mid-infrared wavelengths. However, PDRC materials are easily contaminated by rain water, settled dust, microorganisms etc., which cause degradation in the cooling performance. Herein, we developed a porous composite film of ethylene-propylene-diene copolymer (EPDM) and hydrophobic SiO2 particles integrating superhydrophobic self-cleaning and radiative cooling. The film consists of EPDM micropores filled with numerous SiO2 agglomerations, resulting in solar reflectance of 96% with an average emissivity of 95% and superhydrophobicity with water contact angle of 162° and sliding angle of 1.2°. The film achieved a sub-ambient temperature drop of 12 °C in sealed air and 7 °C in open air under direct sunlight. Importantly, the superhydrophobic self-cleaning effect of the film prevents its surface from outdoor contamination or wetting, favoring long lasting cooling efficiency, which is promising in applications for cooling electronic devices, vehicles, building materials, etc.

Effects of mixing process on spatial distribution and coexistence of sulfur and zinc in vulcanized EPDM rubber

Vulcanization of rubber is performed through mechanical mixing of rubber, sulfur, and zinc oxide (ZnO). Sulfur cross-links the rubber by reacting with the double bonds in the rubber, and ZnO is an activator that efficiently accelerates the vulcanization of rubber with sulfur. The extent of coexistence of sulfur and ZnO is an important factor for ensuring effective cross-linking and sufficient dispersion. In this study, we successfully observed the spatial distributions of sulfur and zinc as well as their spatial correlation in vulcanized ethylene–propylene–diene copolymer (EPDM) rubber using microscopic X-ray fluorescence mapping with synchrotron radiation. We found that the mixing processes substantially affects the extent of coexistence of sulfur and ZnO, as well as the spatial distribution of each component. The improved spatial cross-correlation and homogeneity of sulfur and zinc enhances the performance of EPDM rubber.

Reactive compatibilization as a proper tool to improve PA6 toughness

Polyamide 6 (PA6) is a widely applied thermoplastic, however, drawbacks as low notch impact strength and high moisture absorption hinder its commercialization. Seeking improvements for PA6, this work investigated blends based on PA6/maleic anhydride grafted ethylene propylene diene copolymer (EPDM-MA) with 1% maleic anhydride (MA). In the first step, blends were processed using a co-rotational twin-screw extruder, afterwards, pellets were injection moulded. Torque rheometry, impact strength, tensile strength, thermal deflection temperature (HDT), differential scanning calorimetry (DSC), contact angle and scanning electron microscopy (SEM) were performed and the main properties were defined. Torque of PA6/EPDM-MA blends increased compared to neat PA6. Only subtle decreases were verified in the tensile strength, elastic modulus and HDT parameters. Nevertheless, significant increases were observed for the elongation at break and the impact strength. EPDM-MA addition to PA6 did not affect its melting and crystallization parameters. Contact angle of all blends increased when compared to PA6, suggesting higher hydrophobic character of PA6/EPDM-MA blends. Improved results were collected for EPDM-MA 10%, reaching increases of 850% and 213% in impact strength and elongation at break. From SEM images, particles were observed with diameters ranging from 0.1 to 2 μm, which were well dispersed and properly distributed in the PA6 matrix; additionally, for the blends with 10%; 12.5% and 15% EPDM-MA, higher level of plastic deformation was reached corroborating with the significant increase in the impact strength and elongation at break.

Synergistic effects of ethylene propylene diene copolymer and carbon nanofiber on the thermo-mechanical properties of polypropylene/high-density polyethylene composites

Ethylene–propylene–diene copolymer (EPDM) modified polypropylene (PP)/high-density polyethylene (HDPE) ternary blends and their composites with carbon nanofibers (CNF) were prepared. The PP/HDPE binary blends containing 80/20 concentration was used for the preparation of ternary blends and composites. The amount of EPDM in the ternary blend was 2, 4.8, 9.1, 13 and 16.6 wt%. The best mechanical properties were obtained for the ternary blends containing 13 wt% EPDM. These blends were further modified with CNF of varying concentrations from 0.043 to 1.7 wt%. The mechanical properties of the ternary composites especially with higher concentrations of CNF show a synergistic effect with good improvements in impact strength, tensile strength, tensile elongation, and tensile toughness. The DMA studies validate the homogeneity of the ternary composites. The DSC studies reveal better miscibility/compatibility of the PP/HDPE blends in the presence of EPDM and CNF. The thermal stability of the ternary composites was enhanced due to the better stability of EPDM and the uniform dispersion of the fillers in the polymer matrix. The contact angle values were improved with the addition of EPDM, however, for the ternary composites, only marginal variations in contact angle were observed.

Combined effect of modified titanium carbide (TiC) particles and ethylene alpha olefins (POE) on properties of ethylene propylene diene monomer (EPDM)/TiC/POE composites for electronic application

For the field of flexible electronic materials, titanium carbide (TiC) is still a new member that needs to be further investigated. In this study, the effects of surface modification, TiC content and ethylene alpha olefins (POE) amount on dielectric properties of ethylene propylene diene copolymer (EPDM) are investigated in detail. The addition of 20% modified TiC particles can improve the dielectric constant of EPDM control from 2.4 to 8.7 (360% increase) at 105 Hz. However, the complex viscosity of EPDM control increases by 6.4 times at 1.7 Hz and the volume resistivity decreases by 3 order of magnitude. Moreover, the thermal conductivity of EPDM control only increase by 17%. By comparison, the 20% POE not only increases the dielectric constant of EPDM/TiC (10/2) from 8.7 to 13.5 (55% increase) at 105 Hz, with slight decrease of volume resistivity, but also decreases the complex viscosity of EPDM/TiC (10/2) from 1.19 × 105 Pa·S to 5.78 × 104 Pa·S (51% decrease) at 1.7 Hz. Meanwhile, the addition of 20% POE can further enhance the thermal conductivity of EPDM/TiC (10/2) from 0.281 W/(m·K) to 0.416 W/(m·K) (48% increase).

High-impact Composites of Polypropylene and Nitrile Butadiene Rubber with Improved Compatibility of the Polymer Components, Obtained by Melt Reactive Compounding. Part 1: The Influence of the Nature of the Polar Vinyl Monomer on the Impact Strength and Deformation Strength Properties of the Composites

The effect of the components of the modifying system on the impact strength and deformation strength characteristics of polypropylene/nitrile butadiene rubber (NBR) composites obtained by reactive compounding was investigated. Studies were conducted on composites containing 23 wt% BNKS-18AMN nitrile butadiene rubber and peroxide modifying system coagents – polar vinyl monomers: maleic anhydride (MA), its polyester with monoethylene glycol (MEG), and a complex of MEG with aromatic amine antioxidant Diaphene FP (DFP). At the same time, we introduced presynthesised compatibilisers based on blends of polypropylene with elastomers of different polarity: ternary ethylene propylene diene copolymer (EPDM) and an NBR modified by grafting of MA or MEG + DFP. It was established that, in this series of coagents, the MEG + DFP complex ensures the most effective dispersion of the BNKS-18AMN phase in the polypropylene matrix during reactive compounding of composites and, in accordance with this, leads to a significant increase in their impact strength and elongation at break. Here, the greatest specificity and effectiveness are possessed by compatibilisers into which an elastomer phase has been introduced: blends of polypropylene with non-polar EPDM, modified with MA, or blends with polar BNKS-18AMN, modified with an MEG + DFP complex.

On the Development of Titanium κ1‐Amidinate Complexes, Commercialized as Keltan ACE™ Technology, Enabling the Production of an Unprecedented Large Variety of EPDM Polymer Structures

ABSTRACTARLANXEO Elastomers has developed and commercialized Keltan ACE™ technology, a class of half‐sandwich cyclopentadienyl κ1‐amidinate metal complexes, which are extremely active for the production of first‐class ethylene/propylene/diene copolymers (EPDM). In this review, the development and some of the key features of the Keltan ACE™ catalyst system are presented. Many different ACE catalysts have been synthesized over the past years, including bridged and bimetallic catalysts. With Keltan ACE™, a complete range of EPDM products with similar polymer characteristics as their Ziegler–Natta (ZN) counterparts can be produced, including variations containing very high 5‐ethylidene‐2‐norbornene (ENB) contents, controlled long chain branching, very high molecular weight, as well as oil‐extended products. Moreover, other EPDM structures can be polymerized. The Keltan ACE™ catalyst technology also allows the production of EPDMs with very high amounts of dicyclopentadiene (DCPD) or 5‐vinyl 2‐norbornene (VNB) without excessive gelation and reactor fouling, that is, products that cannot or are extremely difficult to obtain via classical ZN catalysis. In a next step, high‐VNB‐EPDM can be postreactor modified, for example, via metathesis chemistry. In addition, EPDM polymers with a very broad or even bimodal molecular weight distribution can be obtained in a single reactor with certain ACE catalyst structures at particular activator/precatalyst ratios. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2877–2891

Synthesis of silane‐grafted ethylene vinyl acetate copolymer and its application to compatibilize the blend of ethylene‐propylene‐diene copolymer and silicone rubber

Vinyltrimethoxysilane‐grafted ethylene vinyl acetate copolymer (EVA‐g‐VTMS) was synthesized and applied to compatibilize ethylene‐propylene‐diene copolymer (EPDM)/methyl vinyl silicone rubber (MVQ) blends. The silane‐grafting was successfully proved by differential scanning calorimetry, FTIR spectroscopy and XPS spectroscopy. The additive amount of the compatibilizer (EVA‐g‐VTMS) was optimized to be 10 phr (parts per hundred of rubber in weight) based on analysis of scanning electron microscopy, mechanical properties, aging properties, dynamic mechanical properties, rheological properties and thermal properties. Compared with the blend without EVA‐g‐VTMS, results show that the blend with 10 phr of EVA‐g‐VTMS exhibits the finest morphology. Tensile strength, elongation at break, modulus at 100% elongation, tear strength and TE index increase by 82.5%, 16.9%, 60.0%, 40.9%, and 41.9%, respectively. Dynamic mechanical analysis reveals storage modulus increase and glass transition temperatures of EPDM and MVQ move closer to each other. Rheological analysis shows a decrease in complex modulus and complex viscosity, and the processibility of the blend was improved. Furthermore, thermogravimetric analysis shows enhancement of thermal stability. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers

Dielectric spectroscopic analysis of degradation in ethylene-propylene-diene copolymer

Gamma-ray induced changes occurring in ethylene-propylene-diene copolymer (EPDM) were analyzed through its complex permittivity spectra. First, four different processes, namely, instantaneous polarization, hopping of ions, segmental relaxation, and dc conduction are found to contribute to the complex permittivity. By fitting the spectra to theoretical equations, it has become clear that the instantaneous polarization and ionic hopping become active by the irradiation, indicating that generation of oxidative products and mobile ions and occurrence of chain scission are induced by gamma rays. Furthermore, since both the thermal expansion and the contribution of the segmental relaxation to the permittivity become less with an increase in dose, it is assumed that crosslinking is induced by the gamma irradiation.

Effects of the structure and insulation material of a cable on the ability of a location method by FDR

The authors have demonstrated that the estimation of the precise locations of points in cables aged thermally or mechanically or by the irradiation of gamma rays is possible by a combination of frequency domain reflectometry and inverse fast Fourier transform. This paper examines how this ability of fault location depends on the type, structure, and insulation material of the cable, using several kinds of polymer insulated cables such as a triple core cable insulated with flame-retardant ethylene propylene diene copolymer, a dual core cable insulated with silicone rubber, a dual core cable insulated with crosslinked polyolefin (XLPO), a coaxial cylindrical cable insulated with low density polyethylene, and a flat cord insulated by polyvinyl chloride (PVC). As a result, for cables with lengths from 16 to 72 m, the maximum sensitivity is attained when the highest frequency of the inputted electromagnetic waves is 1.0 GHz or higher for coaxial cables, but around 300 to 800 MHz for dual or triple core cables. For the location attempt of the position heated by a heater, cables insulated with PVC give higher signal intensities than those insulated with XLPO.

Study on radiation aging of PA6/EPDM blends

The modification in the stability of polyamide-6 (PA6)/ethylene-propylene diene copolymer (EPDM) was studied by isothermal and non-isothermal chemiluminescence and FTIR spectroscopy. The compositions of the blends consisted of PA-6 as basic component and EPDM as the second component at different loadings (0, 10, 20, and 30 wt %). The exposure to γ-radiation (137Cs) was performed in air at room temperature at five total doses of 10, 25, 50, 100 and 160 kGy and dose rate of 0.4 kGy h−1. The different oxidation rates were correlated with the elastomer concentration according to the dissimilarity between the radiation resistance of the components. The maximum CL intensities attained at 210 °C corresponded to the highest oxidation rates in non-isothermal CL spectra. The delayed oxidation was due to the presence of elastomer which was noticed in the non-isothermal CL intensities of all compositions. The isothermal CL determinations revealed the contribution of elastomer to the oxidative strengths of PA-6/EPDM compounds. The non-isothermal chemiluminescence determinations confirmed that the main source of radicals along the γ-radiation exposure was EPDM component. The slight shift of the temperature peaks, characterizing the maximum oxidation levels, was noticeable by higher EPDM concentrations. The propagation of oxidation was likely supported by the intermediates appeared in elastomeric phase which could split at tertiary carbon atoms easier. FTIR records highlight the contribution of each component in oxidation process.

Diagnosis of surface degradation of flame-retardant ethylene propylene diene copolymer by scanning probe microscopy

Most electric cables installed in nuclear power plants use organic polymers for their electrical insulation. Regarding this, degradation of the polymers could lead to fatal accidents. However, no truly reliable diagnostic methods that can detect the degradation of polymer insulation in electric cables have been established. Therefore, development of a reliable diagnostic method is very important. The present research shows that scanning probe microscopy can be a good tool to evaluate microscopic changes induced on the surface of flame-retardant ethylene propylene diene copolymer by its degradation.

Preparation, stability and mechanical property of shape-stabilized phase change materials

Abstract A series of shape-stabilized phase change materials (SSPCMs) were prepared by melt blending with paraffin and polymer alloys. The polymer alloys used in this work are high-density polyethylene (HDPE) with various elastomers including ethylene–propylene–diene copolymer (EPDM), three styrene–butadiene–styrene block copolymers (SBS) with different S/B ratios and configurations and styrene–isoprene–styrene block copolymer (SIS). These alloys were used as matrices to encapsulate and support paraffin. Their thermal properties, cyclic stability and mechanical properties were investigated by differential scanning calorimetry (DSC), cyclic stability test and tensile test respectively. The results indicate that these alloys are able to encapsulate paraffin well with latent heats of 80–100 J/g and mass loss of 8–10% after 100 cycles. Crosslinking of the matrices was carried out and its effects on tensile property and cyclic stability were explored. Proper crosslinking can increase the tensile strength without sacrificing the cyclic stability.

Estudo do Efeito da Adição de PP Reciclado nas Propriedades Mecânicas e de Escoamento de Misturas de PP/EPDM

Misturas de polipropileno, PP, e terpolimero de etileno-propileno-dieno, EPDM, sao amplamente utilizadas na industria automobilistica, principalmente em parachoques, cuja destinacao, apos o seu uso, devera atender a Politica Nacional de Residuos Solidos. No presente trabalho, o efeito da incorporacao de PP reciclado nas propriedades mecânicas e de escoamento das misturas PP virgem/EPDM foi avaliado atraves de um planejamento fatorial do tipo 2n, com n = 3 fatores: teor de PP reciclado, perfil de temperatura de processamento e velocidade de rotacao da rosca. As variaveis de resposta analisadas foram: modulo de Young, resistencia ao impacto e indice de fluidez (MFI). Os resultados mostraram que o aumento da temperatura de processamento tende a aumentar a rigidez, a resistencia ao impacto e a fluidez do produto final. O aumento da velocidade de mistura mostrou uma influencia mais significativa na resistencia ao impacto do material; enquanto o aumento do teor de reciclado na mistura PP virgem/EPDM levou ao aumento das propriedades mecânicas, bem como do indice de fluidez do produto.

How do the shape of clay and type of modifier affect properties of polymer blends?

AbstractPolyamide 6/ethylene–propylene–diene metallocene terpolymer/(ethylene–propylene–diene copolymer)‐graft‐(maleic anhydride) blends with clay (3 and 5 wt % depending on the formulation), different clays (montmorillonite and sepiolite) and different surface functionalization (ammonium salts and silanes) were studied to analyze the effect of the shape of clay and type of modifier on their properties. The results have shown that sepiolite has higher influence on the morphology and on the mechanical properties than montmorillonite. In that sense, blends with 3 wt % of sepiolite have reached the best balanced properties, i.e., tensile modulus and impact strength, than their homologous with montmorillonite. Furthermore, the blends with 3 wt % of sepiolite have reached the highest mechanical properties compared with blends with higher montmorillonite content. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Deformation reversibility enhancement of thermoplastic vulcanizates based on high density polyethylene and ethylene–propylene–diene terpolymer

Thermoplastic vulcanizates (TPVs) based on high density polyethylene (HDPE)/ethylene–propylene diene copolymer (EPDM) blends with different compositions of polyethylene–octene elastomer (POE) were prepared by dynamic vulcanization, the effects of the POE incorporation on deformation reversibility enhancement, mechanical, dynamic mechanical and morphological properties of the TPVs were investigated systematically. Characterization via FE-SEM confirms the tearing strips on the fracture surface of HDPE/EPDM TPVs were formed by the residual plastic deformation of HDPE lamellae crystals, which also resulted in the relatively high permanent deformation of TPVs. The elasticity of TPV matrix was improved greatly by the incorporation of POE and the tension set was decreased obviously. RPA results show that the increasing frequency led to the increased elastic modulus while the incorporation of POE in matrix led to the decreased elastic modulus. The tan δ decreased continuously with the increasing frequency and the incorporation of POE had a non-ignorable influence on the tan δ of HDPE/EPDM TPVs.

Damping Properties of Blends Based on EVM

The mechanical and damping properties of blends of ethylene-vinyl acetate rubber (VA content >40% wt) (EVM)/ethylene-propylene-diene copolymer (EPDM) and EVM/nitrile butadiene rubber (NBR), both with 1.4 phr BIPB (bis (tert-butyl peroxy isopropyl) benzene) as curing agent, were investigated by dynamic mechanical analysis (DMA). The effect of added polyvinyl chloride (PVC), amido donor N-cyclohexyl-2-benzothiazole sulfonamide (CZ), and dicumyl peroxide (DCP) as a substitute curing agent, on the damping and mechanical properties of both rubber blends were studied. The results showed that in EVM/EPDM/PVC blends, EPDM was immiscible with EVM and could not expand the damping range of EVM at low temperature. PVC was miscible with EVM and dramatically improved the damping property of EVM at high temperature while keeping good mechanical performance. In EVM/NBR/PVC blends, PVC was partially miscible with EVM/NBR blends and remarkably widened the effective damping temperature range (EDTR) from 41.1°C for EVM/NBR to 62.4°C. Curing agents BIPB and DCP had a similar influence on EVM/EPDM blends. DCP, however, dramatically raised the height of tan δ peak of EVM/NBR = 80/20 and expanded its EDTR to 64.9°C. CZ had no obvious influence on the EVM/EPDM blends cured with BIPB. However, a small content of CZ enlarged the tan δ peak of EVM/NBR = 80/20 in both height and width, but at the cost of a deterioration of mechanical performance.

Dynamically vulcanized blends of polyethylene–octene elastomer and ethylene–propylene–diene terpolymer

Thermoplastic vulcanizates (TPVs) based on polyethylene–octene elastomer (POE)/ethylene–propylene diene copolymer (EPDM) blends were prepared by dynamic vulcanization, the effects of the EPDM incorporation on mechanical, dynamic mechanical and morphological properties of the TPVs were investigated systemically. Experimental results indicate that compared with pure POE, the improvement of mechanical properties of POE/EPDM blends was achieved; the tensile strength and tearing strength reached the maximum at an EPDM content of 20 wt.%. It is interesting to note that the tensile set at break was decreased almost linearly with increasing EPDM loading, decreasing from 190% (at 0 phr EPDM) to 55% (at 30 wt.% EPDM), indicating the relatively large permanent deformation of POE is improved remarkably by the incorporation with EPDM. Phase contrast microscopy studies show that the vulcanized EPDM particles were uniformly dispersed in the POE matrix. RPA results show that the elastic modulus increased with increasing frequency, moreover, it is noteworthy that the storage modulus of dynamically vulcanized POE/EPDM blends was higher than that of pure POE, however, the storage modulus decreased with increasing EPDM content, the incorporation of EPDM had almost no influence on the tan δ.

Toughened poly(trimethylene terephthalate) by blending with a functionalized ethylene–propylene–diene copolymer

AbstractA series of blends of poly(trimethylene terephthalate) (PTT) with ethylene–propylene–diene copolymer grafted with maleic anhydride (EPDM‐g‐MA) were prepared in composition by weight 95/5, 90/10, 80/20, and 70/30. Their morphologies, crystallization behavior, and mechanical properties were investigated. Morphology observation shows the well‐dispersed domains of EPDM‐g‐MA in PTT matrix with weight‐average particle size from 0.98 to 3.64 μm when the EPDM‐g‐MA content increases from 5% to 30% (mass fraction) in the blends. The constancy of the crystallinity level indicates that the elastomeric phase does not disturb the crystallization process of PTT. The addition of rubbery EPDM‐g‐MA to PTT matrix increases the notched Izod impact strength, but impairs the tensile strength properties. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers

The effect of montmorillonite and compatibilizer quantities on stiffness and toughness of polyamide nanoblends

AbstractAlthough polymer blend nanocomposites are widely studied, the balance between stiffness and toughness has not yet been investigated in detail. Some materials producers as well as some sectors in the automotive industry try to improve the toughness of materials without an important loss in stiffness. With this in mind, the aim of the study reported here was to obtain a good balance between toughness and stiffness of polymer blends with different amounts of clay and compatibilizer. In this context, the microstructure of polyamide 6/ethylene–propylene–diene metallocene terpolymer/(ethylene–propylene–diene copolymer)‐graft‐(maleic anhydride) blends with various amounts of clay (2, 3, 4 and 5 wt%) and compatibilizer (10 and 20 wt%) was studied to analyse the achieved morphology to understand the macroscopic properties. The morphology of the rubber phase and the dispersion of the montmorillonite (MMT) are the main factors that influence the mechanical properties. In this sense, the highest Young's modulus is achieved for nanoblends with 5 wt% of MMT, although this nanoblend has the lowest value of notched Izod impact strength. The results obtained suggest that there is a clear trade‐off between stiffness, toughness and temperature behaviour when the ratio of (ethylene–propylene–diene copolymer)‐graft‐(maleic anhydride) to MMT is 5:1. Copyright © 2009 Society of Chemical Industry