Effect of the addition of acrylonitrile/ethylene–propylene–diene monomer (EPDM)/styrene graft copolymer on the morphology–properties relationships in poly(styrene‐co‐acrylonitrile)/EPDM rubber blends

Blends of poly(styrene‐co‐acylonitrile) (SAN) with ethylene–propylene–diene monomer (EPDM) rubber were investigated. An improved toughness–stiffness balance of the SAN/EPDM blend was obtained when an appropriate amount of acrylonitrile–EPDM–styrene (AES) graft copolymer was added, prepared by grafting EPDM with styrene–acrylonitrile copolymer, and mixed thoroughly with both of the two components of the blend. Morphological observations indicated a finer dispersion of the EPDM particles in the SAN/EPDM/AES blends, and particle size distribution became narrower with increasing amounts of AES. Meanwhile, it was found that the SAN/EPDM blend having a ratio of 82.5/17.5 by weight was more effective in increasing the impact strength than that of the 90/10 blend. From dynamic mechanic analysis of the blends, the glass‐transition temperature of the EPDM‐rich phase increased from ?53.9 to ?46.2°C, even ?32.0°C, for the ratio of 82.5/17.5 blend of SAN/EPDM, whereas that of the SAN‐rich phase decreased from 109.2 to 108.6 and 107.5°C with the additions of 6 and 10% AES copolymer contents, respectively. It was confirmed that AES graft copolymer is an efficient compatibilizer for SAN/EPDM blend. The compatibilizer plays an important role in connecting two phases and improving the stress transfer in the blends. Certain morphological features such as thin filament connecting and even networking of the dispersed rubber phase may contribute to the overall ductility of the high impact strength of the studied blends. Moreover, its potential to induce a brittle–ductile transition of the glassy SAN matrix is considered to explain the toughening mechanism. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1685–1697, 2004     

Compatibilization of PP/PE blends and scraps with Royalene: Mechanical properties,SAXS, and WAXS

PP/PE 93/7 model virgin blends and recycled scraps were compatibilized with Royalene (EPDM/PE 65/35 blend) and mechanically tested. No differences in impact and tensile properties between them were found. However, the tensile-impact strength increased almost twice with 10%-compatibilized sample in comparison with uncompatibilized ones. The yield stress of blends containing 10% Royalene decreased to 75–80% of the original value. This effect is in agreement with microhardness measurements; the increase in the compatibilizer content causes softening of the blend. The elongation at break and elongation at yield do not depend on the compatibilizer concentration. The compatibilizer does not influence the degree of crystallinity (WAXS data) of the blends either. Vickers microhardness is in good agreement with Tabor's relationship. The differences between long periods of HDPE in Royalene and LDPE in PP/PE blends (SAXS) proved PE/EPDM interaction. The interaction plays a key role in the toughening of PP/PE blends. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Influence of premade and in situ compatibilizers in polypropylene/ethylene–propylene–diene terpolymer thermoplastic elastomeric olefins and thermoplastic vulcanizates

During dynamic vulcanization of polypropylene (PP)/ethylene–propylene–diene terpolymer (EPDM) blends with dicumyl peroxide/triallyl cyanurate, there is a possibility of the generation of in situ graft links at the interface. Three potential compatibilizers (PP‐grafted EPDM, styrene–ethylenebutylene–styrene, and trans‐polyoctenamer) for PP/EPDM blends were first investigated as references to obtain a quantified insight into the effects to be expected from in situ graft links. Only the first compatibilizer showed some compatibilizing action in straight, unvulcanized blends, as evidenced by a slight increase in the tensile strength of the blend and a somewhat smaller EPDM particle size within the PP matrix. Also, dynamic mechanical testing, in particular, the glass‐transition temperatures of the PP and EPDM components, showed some signs of compatibilization. The PP‐grafted EPDM resembled most closely the structures of PP and EPDM. In the spectra obtained with high temperature, solid‐state NMR, there was an indication that PP–EPDM graft links were generated during the dynamic vulcanization process that still remained after the extraction of the free PP phase from the thermoplastic vulcanizate film. NMR relaxation experiments gave further evidence for the graft links formed in situ. In all cases, only qualitative indications could be achieved because of the extremely low number of graft links formed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3877–3888, 2006     

Investigation of crystallization behavior in dynamically vulcanized EPDM–nylon copolymer blends

A thermoplastic vulcanizate (TPV) of a ethylene–propylene–diene terpolymer (EPDM) and nylon copolymer (PA) was prepared by dynamic vulcanization. Maleic anhydride (MAH)–grafted EPDM (EPDM–g–MAH), MAH‐grafted EPR (EPR–g–MAH), and chlorinated polyethylene (CPE) were used as compatibilizers. The effect of dynamic vulcanization and compatibilizer on the crystallization behavior of PA was investigated. Differential scanning calorimeter measurement results showed no pronounced shift in the crystallization temperature for PA in EPDM–PA TPV compared to that for PA in the neat state, whereas the crystallization temperature increased after adding compatibilizer. The decrease in the crystallinity of TPVs was a result of the crystallization occurring in confined spaces between rubber particles. The equilibrium melting temperature (Tm⁰) of the PA copolymer was measured and was determined to be 157°C. The isothermal crystallization kinetics of PA in the neat and TPV states also was investigated. The crystallization rate was highest in the compatibilized TPV and lowest in the neat PA, whereas it was intermediate in the uncompatibilized TPV unvulcanized blends. Compared with unvulcanized EPDM–PA blends, the dynamic vulcanization process seemed to cause an obvious increase in the crystallization rate of the PA copolymer, especially when a suitable compatibilizer was used. This occurred because the dynamic vulcanization introduced fine crosslinked rubber particles that could act as heterogeneous nucleating centers. In addition, the use of a suitable compatibilizer permitted the formation of finely dispersed vulcanized rubber particles and therefore increased the density of the nucleating centers. The complex morphology of the blends was investigated by atomic force microscopy to evaluate the effect of compatibilizer on the size of the dispersed rubber particles. Compared with the morphology of TPVs with the same dosage of EPDM–g–MAH compatibilizer, the morphology of TPVs using EPR–g–MAH as compatibilizer showed much smaller dispersed rubber particles, which may have contributed to the higher crystallization rate. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 824–829, 2003     

Surface segregation of polyethylene in low‐density polyethylene/ethylene–propylene–diene rubber blends: Aspects of component structure

Aspects of the molecular weight and its distribution, the branching of low‐density polyethylene (LDPE), and the molecular composition of the ethylene–propylene–diene rubber (EPDM) matrix are presented in this article in terms of their influence on the surface segregation of polyethylene (PE) in elastomer/plastomer blends. All of the PEs studied, despite different weight‐average molecular weights and degrees of branching, segregated to the surface of the LDPE/EPDM blends. Atomic force microscopy pictures demonstrated defective crystalline structures on the surface of the blends, which together with a decrease in the degrees of their bulk crystallinity and a simultaneous increase in their melting temperatures, pointed to a low molecular weight and a defective fraction of PE taking part in the surface segregation. The extent of segregation depended on the molecular structure of the EPDM matrix, which determined the miscibility of the components on a segmental level. The higher the ethylene monomer content in EPDM was, the lower was the PE content in the surface layer of the blends. The composition and structure of the surface layer was responsible for its lower hardness in comparison with the bulk of the blends studied. The surface gradient of the mechanical properties depended on the physicochemical characteristics of the components and the blend composition, which created the possibility of tailoring the LDPE/EPDM blends to dedicated applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 625–633, 2006     

Recycling of EPDM waste. II. Replacement of virgin rubber by ground EPDM vulcanizate in EPDM/PP thermoplastic elastomeric composition

Virgin ethylene propylene diene monomer (EPDM) rubber in a thermoplastic elastomeric blend of polypropylene (PP) and EPDM rubber was substituted by ground EPDM vulcanizate of known composition, after which the mechanical properties of the raw EPDM/waste EPDM/PP blends were determined. The ratio of the rubber content in the waste EPDM (r‐W‐EPDM) to the raw EPDM (R‐EPDM) in the blends was varied from 0 : 100 to 45 : 55. Attempts to replace higher amounts (>45%) of R‐EPDM by W‐EPDM failed because of processing difficulty. Although a drop in mechanical properties of the blends was observed at lower loadings of W‐EPDM, the properties showed improvement at intermediate W‐EPDM loadings. The R‐EPDM/W–EPDM/PP blends were found to be reprocessable. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3304–3312, 2001     

Mechanical properties and morphology of PP/ABS blends compatibilized with PP‐g‐2‐HEMA

Polypropylene (PP) and acrylonitrile–butadiene–styrene blends of different composition were prepared using a single‐screw extruder. The binary blend of PP/ABS was observed to be incompatible and shows poor mechanical properties. PP‐g‐2‐hydroxyethyl methacrylate (2‐HEMA) was used as a compatibilizer for the PP/ABS blends. The ternary compatibilized blends of PP/ABS/PP‐g‐2‐HEMA showed improvement in the mechanical properties. Electron micrographs of these blends showed a homogeneous and finer distribution of the dispersed phase. The mechanical performance increased particularly in the PP‐rich blend. The 2.5‐phr (part per hundred of resin) compatibilizer was observed to bring improvement to the properties. The suitability of various existing theoretical models for the predication of the tensile moduli of these blends was examined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 72–78, 2003     

Morphological evolution and properties of thermoplastic vulcanizate/organoclay nanocomposites

Nanocomposites composed of organoclay and thermoplastic vulcanizates (TPVs) based on uncompatibilized or compatibilized polypropylene (PP)/ethylene–propylene–diene rubber (EPDM) blends were prepared in this study. The morphology of the nanocomposites was studied with wide‐angle X‐ray diffraction and transmission electron microscopy, which suggested that the addition of the compatibilizer played a key role in determining the morphology of the composites because of their interaction with the clay surface. Scanning electron microscopy study indicated the changes in the morphology of the rubber particles. Dynamic mechanical analysis was also applied to the analysis of these phenomena. Moreover, for nanocomposites with uncompatibilized PP/EPDM blends as the matrix, the samples showed tensile enhancement compared with neat TPV. Although the addition of the compatibilizer changed tensile properties of the composites in a rather different trend, the tensile modulus increased dramatically when the compatibilizer was added. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40618.     

Compatibilization effects of styrenic/rubber block copolymers in polypropylene/polystyrene blends

Compatibilizing effects of styrene/rubber block copolymers poly(styrene‐b‐butadiene‐b‐styrene) (SBS), poly(styrene‐b‐ethylene‐co‐propylene) (SEP), and two types of poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) (SEBS), which differ in their molecular weights on morphology and selected mechanical properties of immiscible polypropylene/polystyrene (PP/PS) 70/30 blend were investigated. Three different concentrations of styrene/rubber block copolymers were used (2.5, 5, and 10 wt %). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the phase morphology of blends. The SEM analysis revealed that the size of the dispersed particles decreases as the content of the compatibilizer increases. Reduction of the dispersed particles sizes of blends compatibilized with SEP, SBS, and low‐molecular weight SEBS agrees well with the theoretical predictions based on interaction energy densities determined by the binary interaction model of Paul and Barlow. The SEM analysis confirmed improved interfacial adhesion between matrix and dispersed phase. The TEM micrographs showed that SBS, SEP, and low‐molecular weight SEBS enveloped and joined pure PS particles into complex dispersed aggregates. Bimodal particle size distribution was observed in the case of SEP and low‐molecular weight SEBS addition. Notched impact strength (a_k), elongation at yield (ε_y), and Young's modulus (E) were measured as a function of weight percent of different types of styrene/rubber block copolymers. The a_k and ε_y were improved whereas E gradually decreased with increasing amount of the compatibilizer. The a_k was improved significantly by the addition of SEP. It was found that the compatibilizing efficiency of block copolymer used is strongly dependent on the chemical structure of rubber block, molecular weight of block copolymer molecule, and its concentration. The SEP diblock copolymer proved to be a superior compatibilizer over SBS and SEBS triblock copolymers. Low‐molecular weight SEBS appeared to be a more efficient compatibilizer in PP/PS blend than high‐molecular weight SEBS. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 291–307, 1999     

Compatibilization of PE/PS and PE/PP blends. I. Effect of processing conditions and formulation

The objective of this work was to study the effectiveness of low‐cost commercial compatibilizers and several processes (internal mixer, single‐ and twin‐screw extruders) for two types of plastic blends: high‐density polyethylene/polypropylene and high‐density polyethylene/polystyrene blends, to gain insight into the recycling of wastes from those frequently encountered mixed plastics. Blends going from a pure A to a pure B component, with and without a compatibilizer, were prepared using an internal mixer, a corotating twin‐screw extruder, as well as a single‐screw extruder to follow an industrial‐convenient process. In both cases, the analyses of blend morphologies highlighted the poor adherence between the two phases in the uncompatibilized blends. Compatibilized blends display better adherence between phases and the ability to process blends made from both single‐ and twin‐screw extruders. When adding a compatibilizer, the viscosity of each blend (PE/PP or PE/PS) increased due to a better adhesion of the phases. Charpy impact tests showed that the presence of the compatibilizer in PE/PS blends increased their impact properties. Indeed, the improvement of the adhesion between the two phases enabled stress transfer at the interface. A single‐screw extruder seems to be efficient as a processing method on an industrial scale when a compatibilizer is used. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2475–2484, 2003     

Effect of styrene–isoprene–styrene,styrene–butadiene–styrene,and styrene–butadiene–rubber on the mechanical,thermal, rheological,and morphological properties of polypropylene/polystyrene blends

The mechanical, thermal, rheological, and morphological properties of polypropylene (PP)/polystyrene (PS) blends compatibilized with styrene–isoprene–styrene (SIS), styrene–butadiene–styrene (SBS), and styrene–butadiene–rubber (SBR) were studied. The incompatible PP and PS phases were effectively dispersed by the addition of SIS, SBS, and SBR as compatibilizers. The PP/PS blends were mechanically evaluated in terms of the impact strength, ductility, and tensile yield stress to determine the influence of the compatibilizers on the performance properties of these materials. SIS‐ and SBS‐compatibilized blends showed significantly improved impact strength and ductility in comparison with SBR‐compatibilized blends over the entire range of compatibilizer concentrations. Differential scanning calorimetry indicated compatibility between the components upon the addition of SIS, SBS, and SBR by the appearance of shifts in the melt peak of PP toward the melting range of PS. The melt viscosity and storage modulus of the blends depended on the composition, type, and amount of compatibilizer. Scanning electron microscopy images confirmed the compatibility between the PP and PS components in the presence of SIS, SBS, and SBR by showing finer phase domains. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 266–277, 2003     

Polypropylene/polypropylene‐grafted acrylic acid copolymer/ethylene–Acrylic acid copolymer ternary blends for hydrophilic polypropylene

Ternary blends of polypropylene (PP), a polypropylene‐grafted acrylic acid copolymer (PP‐g‐AA), and an ethylene–acrylic acid copolymer (EAA) were prepared by melt blending. The surfaces of films with different contents of these three components were characterized with contact‐angle measurements. Scanning electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis were used to characterize the microstructure, melting and crystalline behavior, and thermal stability of the blends. The contact angles of the PP/PP‐g‐AA blends decreased monotonically with increasing PP‐g‐AA content. With the incorporation of EAA, the contact angles of the PP/PP‐g‐AA/EAA ternary blends decreased with increasing EAA content. When the concentration of EAA was higher than 15 wt %, the contact angles of the ternary blends began to increase. Scanning electron microscopy observations confirmed that PP‐g‐AA acted as a compatibilizer and improved the compatibility between PP and EAA in the ternary blends. Differential scanning calorimetry analysis suggested that acrylic acid moieties could act as nucleating agents for PP in the polymer blends. Thermogravimetric analysis and differential thermogravimetry confirmed the optimal blend ratio for the PP/PP‐g‐AA/EAA ternary blends was 70/15/15. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 436–442, 2006     

Synergetic toughness and morphology of poly(propylene)/nylon 11/maleated ethylene‐propylene diene copolymer blends

Polypropylene (PP)/nylon 11/maleated ethylene‐propylene‐diene rubber (EPDM‐g‐MAH) ternary polymer blends were prepared via melt blending in a corotating twin‐screw extruder. The effect of nylon 11 and EPDM‐g‐MAH on the phase morphology and mechanical properties was investigated. Scanning electron microscopy observation revealed that there was apparent phase separation for PP/EPDM‐g‐MAH binary blends at the level of 10 wt % maleated elastomer. For the PP/nylon 11/EPDM‐g‐MAH ternary blends, the dispersed phase morphology of the maleated elastomer was hardly affected by the addition of nylon 11, whereas the reduced dispersed phase domains of nylon 11 were observed with the increasing maleated elastomer loading. Furthermore, a core‐shell structure, in which nylon 11 as a rigid core was surrounded by a soft EPDM‐g‐MAH shell, was formed in the case of 10 wt % nylon 11 and higher EPDM‐g‐MAH concentration. In general, the results of mechanical property measurement showed that the ternary blends exhibited inferior tensile strength in comparison with the PP matrix, but superior toughness. Especially low‐temperature impact strength was obtained. The toughening mechanism was discussed with reference to the phase morphology. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Phase morphology and thermomechanical analysis of poly(styrene‐co‐acrylonitrile)/ethylene–propylene–diene monomer blends: Uncompatibilized and reactively compatibilized blends with two mixing sequences

The phase morphology developing in immiscible poly(styrene‐co‐acrylonitrile) (SAN)/ethylene–propylene–diene monomer (EPDM) blends was studied with an in situ reactively generated SAN‐g‐EPDM compatibilizer through the introduction of a suitably chosen polymer additive (maleic anhydride) and 2,5‐dimethyl‐2,5‐di‐(t‐butyl peroxy) hexane (Luperox) and dicumyl peroxide as initiators during melt blending. Special attention was paid to the experimental conditions required for changing the droplet morphology for the dispersed phase. Two different mixing sequences (simple and two‐step) were used. The product of two‐step blending was a major phase surrounded by rubber particles; these rubber particles contained the occluded matrix phase. Depending on the mixing sequence, this particular phase morphology could be forced or could occur spontaneously. The composition was stabilized by the formation of the SAN‐g‐EPDM copolymer between the elastomer and addition polymer, which was characterized with Fourier transform infrared. As for the two initiators, the blends with Luperox showed better mechanical properties. Scanning electron microscopy studies revealed good compatibility for the SAN/EPDM blends produced by two‐step blending with this initiator. Dynamic mechanical thermal analysis studies showed that the two‐step‐prepared blend with Luperox had the best compatibility. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effects of fillers,maleated ethylene propylene diene diene rubber,and maleated ethylene octene copolymer on phase morphology and oil resistance in natural rubber/nitrile rubber blends

The phase morphology and oil resistance of 20/80 NR/NBR blends filled with different types of fillers and copolymers were investigated. In the case of filler effect, N220, N330, and N660 carbon blacks with different particle sizes were used. Additionally, the blends filled with nonblack‐reinforcing fillers, that is, precipitated and silane‐treated silica, were investigated. To study the compatibilization effect, maleated ethylene propylene diene rubber (EPDM‐g‐MA) and maleated ethylene octene copolymer (EOR‐g‐MA) were added to the blends. The results revealed that the addition of filler, either carbon black or silica, to the blend caused a drastic decrease in NR dispersed phase size. Carbon blacks with different particle sizes did not produce any significant difference in NR dispersed phase size under the optical microscope. Silica‐filled blends showed lower resistance to oil than did the carbon black–filled blends. In addition, it was determined that neither EOR‐g‐MA nor EPDM‐g‐MA could act as a compatibilizer for the blend system studied. The oil resistance of the blends with EPDM‐g‐MA is strongly affected by the overall polarity of the blend. In the case of EOR‐g‐MA, the oil resistance of the blends is significantly governed by both overall polarity of the blend and phase morphology. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1156–1162, 2003     

Study on isotactic polypropylene/zinc‐neutralized sulfonated ethylene propylene diene monomer rubber/CaCO3 ternary blends

The morphological structure and mechanical properties of isotactic polypropylene (PP)/zinc‐neutralized sulfonated ethylene propylene diene monomer rubber (Zn? SEPDM)/CaCO₃ blends were studied. PP/Zn? SEPDM/CaCO₃ blends were prepared through two different sequences. A: Blending PP with Zn? SEPDM, then adding CaCO₃; B: Blending Zn? SEPDM with CaCO₃, then adding PP. The blending sequence has substantial influence on the mechanical properties. SEM micrographs and X‐ray photoelectron spectrometry indicate that the CaCO₃ filler is encapsulated by Zn? SEPDM in those blends prepared through sequence B, which caused an extra increase of impact strength. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1635–1640, 2004     

In situ reactive compatibilization and reinforcement of peroxide dynamically vulcanized polypropylene/ethylene‐propylene‐diene monomer tpv by zinc dimethacrylate

This work demonstrates an approach of in situ reactive compatibilization between polypropylene (PP) and ethylene‐propylene‐diene monomer (EPDM) by using ZDMA as a compatibilizer and, simultaneously, as a very strong reinforcing agent. With 7phr ZDMA in the PP/EPDM (30/70, w/w) thermoplastic vulcanizate (TPV), the tensile strength and elongation at break were increased from 5.3 MPa and 222% up to 11.2 MPa and 396%, respectively. Increasing the PP concentration further improved mechanical properties of the TPVs with ZDMA. This tremendous reinforcing as well as the compatibilization effect of the ZDMA was understood by polymerization of ZDMA and ZDMA reacting with EPDM and PP during peroxide induced dynamic vulcanization. A peculiar nano‐composite structure that the crosslinked rubber particles were “bonded” by a transition zone which containing numerous of nano‐particles with dimensions of about 20–30 nm was observed from transmission electron microscopy (TEM). Scanning electron microscopy (SEM) results showed that increase of PP/EPDM ratio reduced the size of crosslinked EPDM particles. Moreover, we found that the ZDMA reinforced EPDM particles resulted in a higher tan δ peak temperature for EPDM phase and built “filler‐filler”‐like networking in the PP melt. POLYM. COMPOS. 34:1357–1366, 2013. © 2013 Society of Plastics Engineers     

Study on morphology of ternary polymer blends. I. Effects of melt viscosity and interfacial interaction

The morphology of some ternary blends was investigated. In all of the blends polypropylene, as the major phase, was blended with two different minor phases, ethylene–propylene–diene terpolymer (EPDM) or ethylene–propylene–rubber (EPR) as the first minor phase and high‐density polyethylene (HDPE) or polystyrene (PS) as the second minor phase. All the blends were investigated in a constant composition of 70/15/15 wt %. Theoretical models predict that the dispersed phase of a multiphase polymer blend will either form an encapsulation‐type phase morphology or phases will remain separately dispersed, depending on which morphology has the lower free energy or positive spreading coefficient. Interfacial interaction between phases was found to play a significant role in determining the type of morphology of these blend systems. A core–shell‐type morphology for HDPE encapsulated by rubber was obtained for PP/rubber/PE ternary blends, whereas PP/rubber/PS blends showed a separately dispersed type of morphology. These results were found to be in good agreement with the theoretical predictions. Steady‐state torque for each component was used to study the effect of melt viscosity ratio on the morphology of the blends. It was found that the torque ratios affect only the size of the dispersed phases and have no appreciable influence on the type of morphology. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1129–1137, 2001     

Development of an intermediate layer for multilayer hoses used in turbo lines of motor vehicles

Multilayer hoses for turbo lines can be produced by ethylene acrylic rubber (AEM) as the inner layer and peroxide cured ethylene propylene diene monomer (EPDM) as the outer layer. In such a case, the polar AEM should adhere well to the apolar EPDM to ensure proper functioning. In this work, new blends were developed and optimized to offer potential for using as intermediate bonding layers. Different compositions of dipolymer AEM/EPDM and terpolymer AEM/EPDM blends with and without maleic anhydride grafted EPDM (Ma‐g‐EPDM) as a compatibilizer were successfully prepared. Curing behaviors, as well as mechanical and thermal properties of the blends were investigated in detail. The effects of the compatibilizer addition were also explored by dynamical mechanical analysis, DeMattia and scanning electron microscope. It is found that Ma‐g‐EPDM is more effective in terpolymer AEM containing blends. Additionally, 60/40:AEM/EPDM weight ratio is the most suitable proportion for turbo lines. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46525.     

Preparation and characterization of a methyl methacrylate/ethyl acrylate/acrylic acid terpolymer to improve the homogeneity of ethylene–propylene–diene monomer rubber/poly(vinyl chloride) blends

The emulsion terpolymerization of methyl methacrylate (MMA), ethyl acrylate (EA), and acrylic acid (AA) was carried out under a nitrogen atmosphere at 70°C. The final terpolymer conversion was determined gravimetrically. The synthesized MMA–EA–AA terpolymer was characterized with ¹H‐NMR spectroscopy, thermal analysis, and gel permeation chromatography. Glass‐transition temperatures of the MMA–EA–AA terpolymer were determined with a differential scanning calorimeter. Ethylene–propylene–diene monomer rubber (EPDM)/poly(vinyl chloride) (PVC) blends were prepared with different blend ratios (10/90, 20/80, 30/70, 40/60, and 50/50) in the presence and absence of MMA–EA–AA as a compatibilizer. The morphology of those blends was examined with the aid of a scanning electron microscope. The scanning electron micrographs in the presence of the MMA–EA–AA terpolymer illustrated the disappearance of the macroscale phase separation of EPDM/PVC blends as a result of the incorporation of MMA–EA–AA into that blend, indicating an improvement of the homogeneity. The mechanical properties of the EPDM/PVC blend films and the dielectric properties of the melt blends were investigated. The swelling behavior of the cured blends in the brake fluid was also discussed. The results illustrated that the mechanical properties, the weight swelling values, and the dielectric constant values showed linear behavior versus the blend ratios after the incorporation of the terpolymer. However, those values showed deviations from linearity in the absence of the terpolymer. That, in turn, ensured the results obtained with the scanning electron microscope. The results reveal that the MMA–EA–AA terpolymer prepared can be used successfully to improve the homogeneity of EPDM/PVC blends used in hose and oil seal applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008