Mechanical,thermal, and morphological characteristics of compatibilized and dynamically vulcanized polyoxymethylene/ethylene propylene diene terpolymer blends

Dynamically vulcanized blends of polyoxymethylene (POM) and ethylene propylene diene terpolymer (EPDM) with and without compatibilizer were prepared by melt mixing in a twin screw extruder. Maleic anhydride (MAH) grafted EPDM (EPDM‐g‐MAH) has been used as a compatibilizer. Dicumyl peroxide was used for vulcanizing the elastomer phase in the blends. Mechanical, dynamical mechanical, thermal, and morphological properties of the blend systems have been investigated as a function of blend composition and compatibilizer content. The impact strength of both dynamically vulcanized blends and compatibilized/dynamically vulcanized blends increases with increase in elastomer content with decrease in tensile strength. Dynamic mechanical analysis shows decrease in tanδ values as the elastomer and compatibilizer content increased. Thermograms obtained from differential scanning calorimetric studies reveal that compatibilized blends have lower T_m values compared to dynamically vulcanized blends, which confirms strong interaction between the plastic and elastomer phase. Scanning electron microscopic observations on impact fractured surface indicate reduction in particle size of elastomer phase and its high level of dispersion in the POM matrix. In the case of compatibilized blends high degree of interaction between the component polymers has been observed. POLYM. ENG. SCI., 47:934–942, 2007. © 2007 Society of Plastics Engineers     

The Compatibilization of EPDM/SBR Blends by EPDM-Graft-Styrene Copolymer

Abstract

Ethylene propylene diene rubber (EPDM) and styrene butadiene rubber (SBR) blends were compatibilized by a graft copolymer EPDM-graft-styrene. This compatibilizer was prepared by gamma radiation induced grafting of EPDM with styrene monomer. The compatibilized blends were evaluated by scanning electron microscope and dielectric properties. The obtained results reveal that the addition of a small percentage of graft copolymer to EPDM/SBR blends improves the physico-mechanical properties of the blend vulcanizates, and this can be related to the enhancement of the blend compatibility.     

Improved mechanical properties of NR/EPDM blends by controlling the migration of curative and filler via reactive processing technique

Simple blending of natural rubber/ethylene–propylene–diene rubber (NR/EPDM) generally results in inferior mechanical properties because of curative migration and their differences for filler affinity. In this work, the 70/30 and 50/50 NR/EPDM blends prepared by reactive processing techniques were investigated and compared with the simple, nonreactive blends. The reactive blend compounds were prepared by preheating EPDM, containing all curatives to a predetermined time related to their scorch time prior to blending with NR. For the 70/30 gum blends, four types of accelerators were studied: 2,2‐mercaptobenzothiazole (MBT), 2,2‐dithiobis‐ (benzothiazole) (MBTS), N‐cyclohexyl‐2‐benzothiazolesulfenamide (CBS), and N‐tert‐butyl‐2‐benzothiazolesulfenamide (TBBS). When compared with the simple blends, the reactive blends cured with CBS and MBTS showed a clearly improved tensile strength whereas the increase of tensile strength in the blends cured with TBBS and MBT was marginal. However, a dramatic improvement of ultimate tensile properties in the reactive 50/50 NR/EPDM blends cured with TBBS was observed when compared with the simple blend. For the N‐550‐filled blends at the blend ratios of 70/30 and 50/50, the reactive‐filled blends prepared under the optimized preheating times demonstrated superior tensile strength and elongation at break over the simple blends. The improved crosslink and/or filler distribution between the two rubber phases in the reactive blends accounts for such improvement in their mechanical properties. This is shown in the scanning electron micrographs of the tensile fractured surfaces of the reactive blends, which indicate a more homogeneous blend. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

On the compatibilization and dynamic vulcanization of polyacetal/ethylene propylene diene terpolymer blends

This study describes an attempt to improve the impact resistance of polyacetal (POM)/ethylene propylene diene terpolymer (EPDM) blends by means of compatibilization and dynamic vulcanization. A commerical copolymer, poly(acrylic acid)-grafted polypropylene (PGP), has been used as a compatibilizer to control the phase morphology of the blend system. Dicumyl peroxide is used to dynamically vulcanize the EPDM elastomer in the blend. At temperatures higher than 185°C, the compatibilizer decreases the viscosity of compatibilized and dynamically vulcanized (cdv) POM/EPDM blends. Impact strength of the cdv blend system increases considerably with a marginal decrease in tensile yield stress and heat deflection temperature as the PGP content increases. The significant increase in impact strength seems to be due to the role of PGP as a linking agent for the binary blends rather than as a third component. Though dynamic mechanical studies do not indicate any compatibility in cdv-POM/EPDM blends, scanning electron microscopy reveals the strong interpenetrating interphase in the compatibilized blend system. Dynamic vulcanization raises elastic recovery and tensile modulus of the blends. Hysteresis energies of the blends increase consistently with the addition of PGP. The crystalline structure of POM is not affected by compatibilization and vulcanization. © 1994 John Wiley & Sons, Inc.     

Mechanical properties and morphological structures relationship of blends based on sulfated EPDM ionomer and polypropylene

The mechanical properties and morphological structures of blends based on Zn²⁺ neutralized low degree sulfated ethylene propylene diene monomer rubber (Zn–SEPDM) ionomer and polypropylene (PP) were studied. It was found that Zn²⁺ neutralized low degree sulfated EPDM ionomer and PP blends, which are new thermoplastic elastomeric materials, have better mechanical properties than those of PP/EPDM blend. Theoretical analysis of tensile data suggests that there is an increase of the extent of interaction between PP and EPDM in the presence of a low degree of Zn²⁺, which is also an indicator of better interfacial adhesion between PP and Zn–SEPDM than that between PP and EPDM. SEM results proved that the finer dispersed phase sizes and the shorter interparticle distances are the main reasons for the improved mechanical properties of the PP/EPDM blend. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1504–1510, 2004     

Properties and morphologies of elastomer blends modified with EPDM‐g‐poly[2‐dimethylamino ethylmethacrylate]

The graft copolymerization of 2‐dimethylamino ethylmethacrylate (DMAEMA) onto ethylene propylene diene mononer rubber (EPDM) was carried out in toluene via solution polymerization technique at 70°C, using dibenzoyl peroxide as initiator. The synthesized EPDM rubber grafted with poly[DMAEMA] (EPDM‐g‐PDMAEMA) was characterized with ¹H‐NMR spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). The EPDM‐g‐PDMAEMA was incorporated into EPDM/butadiene acrylonitrile rubber (EPDM/NBR) blend with different blend ratios, where the homogeneity of such blends was examined with scanning electron microscopy and DSC. The scanning electron micrographs illustrate improvement of the morphology of EPDM/NBR rubber blends as a result of incorporation of EPDM‐g‐PDMAEMA onto that blend. The DSC trace exhibits one glass transition temperature (T_g) for EPDM/NBR blend containing EPDM‐g‐PDMAEMA, indicating improvement of homogeneity. The physico‐mechanical properties after and before accelerated thermal aging of the homogeneous, and inhomogeneous EPDM/NBR vulcanizates with different blend ratios were investigated. The physico‐mechanical properties of all blend vulcanizates were improved after and before accelerated thermal aging, in presence of EPDM‐g‐PDMAEMA. Of all blend ratios under investigation EPDM/NBR (75/25) blend possesses the best physico‐mechanical properties together with the best (least) swelling (%) in brake fluid. Swelling behavior of the rubber blend vulcanizates in motor oil and toluene was also investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

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

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

Compatibilization of PP/EPDM blends by grafting acrylic acid to polypropylene and epoxidizing the diene in EPDM

In this article, ethylene–propylene–diene‐rubber (EPDM) was epoxidized with an in situ formed performic acid to prepare epoxided EPDM (eEPDM). The eEPDM together with the introduction of PP‐g‐AA was used to compatibilize PP/EPDM blends in a Haake mixer. FTIR results showed that the EPDM had been epoxidized. The reaction between epoxy groups in the eEPDM and carboxylic acid groups in PP‐g‐AA had taken place, and PP‐g‐EPDM copolymers were formed in situ. Torque test results showed that the actual temperature and torque values for the compatibilized blends were higher than that of the uncompatibilized blends. Scanning electron microscopy (SEM) observation showed that the dispersed phase domain size of compatibilized blends and the uncompatibilized blends were 0.5 and 1.5 μm, respectively. The eEPDM together with the introduction of PP‐g‐AA could compatibilize PP/EPDM blends effectively. Notched Izod impact tests showed that the formation of PP‐g‐EPDM copolymer improved the impact strength and yielded a tougher PP blend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3949–3954, 2006     

Natural rubber/ethylene propylene diene blends for high insulation iron crossarms

This research studied the composition and behavior of natural rubber (NR) and ethylene propylene diene monomer (EPDM) blends at various carbon black concentrations (0–30 phr) in terms of electrical resistivity, dielectric breakdown voltage testing, and physical properties. The blends having electrical properties suitable for application in high‐insulation iron crossarms were selected for investigation of compatibility and increased physical properties. The effect of the homogenizing agent concentration on improvement of compatibility of blends was studied by scanning electron microscopy, pulsed nuclear magnetic resonance spectroscopy, and rheology techniques. We also examined mechanical properties such as tensile strength, tear strength, elongation at break, and hardness. The NR/EPDM blends filled with a fixed concentration of silica were investigated for ozone resistance. A carbon black content as high as 10 phr is still suitable for the insulation coating material, which can withstand electrical voltage at 10 kVac. Addition of the homogenizing agent at 5 phr can improve the mechanical compatibility of blends, as evidenced by the positive deviation of shear viscosity of the rubber blend, that is, the calculated shear viscosity being higher than that of experimental data. Moreover, the pulsed NMR results indicated that the spin‐spin relaxation (T₂) of all three components of the rubber blend was compressed upon the addition of the homogenizing agent. The ratio of NR/EPDM in the blend to best resist the ozone gas is 80/20 with the addition of silica of 30 phr into the blend. Also, the NR/EPDM filled with silica had a decreased change in thermal and mechanical properties of blends after thermal aging. The synergistic effect of silica content and high NR content (80) in 20 phr EPDM could improve antioxidation by ozone in the absence of a normal antioxidant for natural rubber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3401–3416, 2004     

Synthesis and characterization of maleated ionomers via ring‐opening reaction of epoxidized styrene‐butadiene rubber with potassium hydrogen maleate and study of their behavior as compatibilizer

A novel method for synthesizing maleate ionomer of (styrene‐co‐butadiene) rubber (SBR) from epoxidized SBR was developed. The epoxidized SBR was prepared via epoxidation of SBR with performic acid formed in situ by H₂O₂ and formic acid in cyclohexane. The maleated ionomer was obtained by ring‐opening reaction of the epoxidized SBR solution with an aqueous solution of potassium hydrogen maleate. The optimum conditions were studied. It was found that it is necessary to use phase transfer catalyst and ring‐opening catalyst for enhancing the epoxy group conversion. To obtain 100% conversion addition of dipotassium maleate is important. The product was characterized by FTIR spectrophotometry and transmission electron microcroscopy (TEM). The results showed that the product was really an ionomer with domains of maleate ionic groups. Some properties of the ionomer, such as water absorbency, oil absorbency and dilute solution behavior were studied. With increasing ionic groups, the water absorbency of the ionomer increases, whereas the oil absorbency decreases. The dilute solution viscosity of the ionomer increases abruptly with increasing ionic group content. The ionomer can be used as a compatibilizer for the blends of SBS and chlorosulfonated polyethylene (CSPE). Addition of a small amount of the ionomer to the blend can enhance the mechanical properties of the blends. 3 wt % ionomer based on the blend can increase the tensile strength and ultimate elongation of the blend nearly twice. The compatibility of the blends enhanced by adding the ionomer was shown by scanning electron microscopy. The blend of equal parts of SBS and CSPE compatibilized by the ionomer behaves as an oil resistant thermoplastic elastomer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 792–798, 2006     

Rheological properties,tensile properties,and morphology of PP/EPDM/lonomer ternary blends

The rheological and tensile properties and the morphology of polypropylene (PP)/ethylenepropylene-diene terpolymer(EPDM)/ionomer ternary blends were investigated, using a rheometric dynamic spectrometer (RDS), a dynamic mechanical thermal analyzer (DMTA), a tensile tester, and a scanning electron microscope (SEM). Two kinds of poly(ethylene-co-methacrylic acid) (EMA) ionomers, neutralized with different metal ions (Na⁺ and Zn⁺⁺), were used. Blends were melt-mixed, using a laboratory internal mixer at 190°C. The composition of PP and EPDM was fixed at 50/50 by wt % and the EMA ionomer contents were varied from 5 to 20 wt %, based on the total amount of PP and EPDM. It was found that the ternary blends, containing Na-neutralized ionomer, showed considerably different rheological properties and morphology as compared to the PP/EPDM binary blends, due to the compatibilizing effect of the ionomer for PP and EPDM, while the ternary blends, containing the Zn-neutralized ionomer, did not. The compatibilizing effect was most prominent at 5 wt % ionomer concentration. © 1994 John Wiley & Sons, Inc.     

Features of the Structure and Properties of Radiation Vulcanizates Based on Blends of Polybutadiene and Ethylene‐Propylene Diene Rubber

Polybutadiene rubber (BR) was blended with ethylene‐propylene diene (EPDM) rubber on rubber mill with different weight ratios (100/0‐70/30‐50/50‐30/70‐0‐100), then application of gamma rays at different irradiation doses from 25 up to 150 kGy to induce crosslinking. Mechanical, physio‐chemical, and characterization of prepared blends are to be followed up as functions of the blend composition and the radiation absorbed dose. Mechanical properties like tensile strength (TS), elongation at break (E_b), and tensile modulus (M₁₀₀) were increased with increasing content of EPDM in blend composition. On the other hand, TS and M₁₀₀ increased with radiation dose, whereas the value of E_b decreased with radiation dose. Physico‐chemical properties like gel fraction and volume fraction of rubber in swollen gel (V_r) increased with increasing the content of EPDM rubber in blend formulation while the swelling ratio and soluble fraction decreased with increasing content of EPDM. On the other hand, the V_r increased with radiation dose, whereas the values of soluble fraction and selling ratio (Q) decreased with radiation dose. Fourier transforms‐infrared measurements confirmed the compatibility between BR and EPDM rubber moieties in the blend matrix. J. VINYL ADDIT. TECHNOL., 25:E64–E72, 2019. © 2018 Society of Plastics Engineers     

Polyoxymethylene/ethylene butylacrylate copolymer/ethylene‐methyl acrylate‐glycidyl methacrylate ternary blends

Blends of compatibilized polyoxymethylene (POM)/ethylene butylacrylate copolymer (EBA)/ethylene‐methyl acrylate‐glycidyl methacrylate copolymer (EMA‐GMA) and uncompatibilized POM/EBA were investigated. The notched impact strength of the compatibilized blends was higher than that of their uncompatibilized counterparts. The toughness of the POM blends was improved obviously with relatively low loading of EBA. Fourier transform infrared spectroscopy (FTIR) spectra of EMA‐GMA, pure POM, and POM/EBA/EMA‐GMA blends indicated that epoxy groups of EMA‐GMA reacted with terminal hydroxyl groups of POM molecular chains. The glass‐transition temperature (T_g) values of the POM matrix and the EBA phase were observed shifted to each other in the presence of EMA‐GMA compatibilizer indicating that the compatibilized blends had better compatibility than their uncompatibilized counterparts. With the addition of EBA to POM, both the compatibilized and uncompatibilized blends showed higher onset degradation temperature (T_d) than that of pure POM and the T_d values of the compatibilized blends were higher than those of their uncompatibilized counterparts. The scanning electron microscopy showed better EBA particles distribution state in the compatibilized system than in the uncompatibilized one. The compatibilized blend with an obvious rougher impact fracture surface indicated the ductile fracture mode. POLYM. ENG. SCI., 58:1127–1134, 2018. © 2017 Society of Plastics Engineers     

Mechanical properties of compatibilized nylon 6/polypropylene blends; studies of the interfacial behavior through an emulsion model

The high interfacial tension between two immiscible phases in a polymer blend often prevents a homogenous stress distribution. Therefore, blends of Nylon 6 (Ny6) and polypropylene (PP) were compatibilized using two commercially available types of PP grafted with maleic anhydride (MAPP) with a low (～2 %) and a high (～7%) grade of maleation. The interfacial tension of compatibilized and non‐compatibilized blends of PA6/PP was calculated from the recoded data of oscillatory rheological measurements using an emulsion model. Both compatibilizers showed similar improvements in tensile strength of up to 25%, but the one low maleation grade compatibilizer showed improved impact properties (>200%). It could be shown that, despite, being more effective in reducing the interfacial tension, using a high grade of maleation in the compatibilizer causes no additional improvement in tensile strength over a low grade of maleation and even has a negative effect on the PA6/PP blend impact strength. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40792.     

Polymer Blends of PBT and PP Compatibilized by Epoxidized Ethylene Propylene Diene Rubber

Summary In this paper, ethylene-propylene-diene-rubber (EPDM) was epoxidized with an in situ formed performic acid to prepare epoxided EPDM(eEPDM). The eEPDM were used to compatibilize poly(butylenes terephthalate)(PBT) and polypropylene(PP) blends in a haake mixer. FTIR results showed that the EPDM had been epoxidized. FTIR and torque test showed the epoxy functional groups in the eEPDM can react with the carboxylic acid or hydroxyl terminal groups in PBT at the interface to form PBT-g-EPDM copolymers. SEM observation showed that these in situ formed grafted copolymers tent to concentrate along the interface to reduce the interfacial tension at the melt and suppress coalescence by steric hindrance. higher quantity of eEPDM compatibilizer in the blend results in a better compatibilized blend in terms of finer phase domains. Notched Izod impact tests showed that both the adding of rubber and the formation of PBT-g-EPDM copolymer improved the toughness of PBT/PP blends.     

The Effect of Dicumyl Peroxide Vulcanization on the Properties & Morphology of Polypropylene/Ethylene-Propylene Diene Terpolymer/Natural Rubber Blends

ABSTRACT

This article discusses some properties such as tensile properties, chemical and oil resistance, gel content, crystallinity, and morphology of polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM)/natural rubber (NR) blends. Dicumyl peroxide (DCP) was applied as a crosslinking agent. In terms of tensile properties, peroxide vulcanized blend shows higher tensile strength and tensile modulus (stress at 100% elongation, M₁₀₀) as compared with the unvulcanized blend. The elongation at break of the peroxide vulcanized blend is higher for the blend with NR rich content compared with the EPDM rich content. The improvements in chemical and oil resistance as well as gel content of peroxide vulcanized blends have also proved the formation of crosslinks in the rubber phase. Scanning electron microscopy (SEM) micrographs from the surface extraction of the blends support that the crosslinks have occurred during dynamic vulcanization. Dynamical vulcanization with DCP has decreased the percent crystallinity of blends that can be attributed to the formation of crosslinks in the rubber.     

Composites based on CB/CF/Ag filled EPDM/NBR rubber blends with high conductivity

For many applications of conductive rubbers, it is desirable to endow the conductive rubber with high conductivity at low conductive filler loading. In this work, composites based on ethylene‐propylene‐diene monomer (EPDM) rubber and nitrile‐butadiene rubber (NBR) were prepared using carbon blacks, carbon fibers, and silver powders as fillers. As the weight fraction of silver powder increased, the hardness of composites increased gradually while the tensile strength and elongation at break decreased. SEM revealed that the EPDM/NBR blends exhibited a relatively co‐continuous morphology. The differential scanning calorimetry (DSC) curves reported the EPDM/NBR rubber blends were incompatibility. The thermogravimetry (TG) studies showed that adding a small amount of silver powder could improve the thermal stability of composites. These conductive composites exhibited good electrical property. At room temperature, when the total volume fraction of fillers was 15.20%, the volume resistivity of EPDM/NBR blend was only 0.0058 Ω cm. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41357.     

Modification of Ethylene Propylene Diene Terpolymer Rubber by Some Thermoplastic Polymers

Abstract

Blends of ethylene propylene diene terpolymer (EPDM) rubber with thermoplastic polyolefins such as low‐density polyethylene (LDPE), high‐density polyethylene (HDPE), high molecular weight polypropylene (PP), and polypropylene random copolymer grade (PP‐R) were prepared by melt mixing. The physico‐mechanical properties, equilibrium swelling in benzene, and aging properties of the binary blends were investigated, analyzing the effect of the rubber/thermoplastics ratio and the type of the thermoplastic material on these properties. The data obtained indicate that EPDM/PP‐R blend in 20/80 w/w% shows the highest physico‐mechanical properties with improved retained tensile strength at 90°C for 7 days. This blend ratio also gives excellent retained equilibrium swelling in benzene at room temperature for 7 days, although EPDM/LDPE blend in 80/20 w/w% imparts the highest retained elongation at break at 90°C for 7 days.     

Oxidation‐grafting surface modification of waste silicone rubber composite insulator powder: Characterizations and properties of EPDM/modified waste powder composites

In order to broaden the applications of waste silicone rubber composite insulator powder (WSP), modified waste powder (WSP‐KH570) was prepared by a two‐step treatment process involving improved surface oxidation approach by using acidic H₂O₂ solution and subsequently grafting of KH570. Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR‐ATR) analysis revealed the presence of KH570 on the powder surface. The result was confirmed by thermogravimetric analysis (TGA). Blends of ethylene propylene diene monomer (EPDM) with WSP‐KH570 were prepared. The effects of WSP‐KH570 on mechanical properties and thermal properties of the blends were investigated. The WSP‐KH570 showed an observed improvement in tensile strength and elongation at break of EPDM/WSP‐KH570 blends compared with corresponding compositions of EPDM/WSP blends. The TGA cure showed that EPDM filled with WSP‐KH570 had higher thermal stability at 210–380 °C than EPDM/WSP. Dynamic mechanical analysis indicated EPDM and WSP‐KH570 were better miscible with the blend ratio (90/10). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45438.     

The control of miscibility of PP/EPDM blends by adding lonomers and applying dynamic vulcanization

The control of miscibility for isotactic polypropylene (PP) and ethylene-propylene-diene terpolymer (EPDM) has been attempted by adding poly(ethylene-comethacrylic acid) (EMA) ionomers and by applying dynamic vulcanization. The rheological properties, crystallization behavior, and morphology of the dynamically vulcanized EPDM/PP/ionomer ternary blends were investigated with a Rheometrics dynamic spectrometer (RDS), a differential scanning calorimeter (DSC), and a scanning electron microscope (SEM). Two kinds of EMA ionomers neutralized with different metal ions (Na⁺ and ZN⁺⁺) were investigated. Blends were prepared on a laboratory internal mixer at 190°C. Blending and curing were performed simultaneously, i.e., EPDM was vulcanized with dicumyl peroxide (DCP) in the presence of PP/ionomer. The composition of PP and EPDM was fixed at 50/50 by wt% and the contents of EMA ionomer were vaired from 5 to 20 parts based on the total amount of PP and EPDM. It was found that the addition of ionomers and the application of the dynamic vulcanization were effective in enhancing the miscibility of PP and EPDM. The structure of the blends was controlled by the following three component phases, i.e., the phase of the dynamially valcanized EPDM, PP, and Zn-neutralized ionomer. The ternary blends showed more miscibility than the PP/EPDM binary blend. This is due to the thermoplastic interpenetrating polymer network (IPN) of the ternary blends. The structure and properties of the ternary blends differed, depending on the types and contents of ionomer, i.e., the ternary blend containing Na-neutralized ionomer did not show a thermoplastic IPN structure clearly, even though the blend was prepared by dynamic vulcanization. The ternary blend containing Zn-neutralized ionomer clearly showed the behavior of a thermoplastic IPN when the contents of ionomer and DCP were 15 parts and 1.0 part, respectively.