Characterization and properties of LDPE/(ground tire rubber)/crosslinked butyl rubber blends

In recent years, interest in used rubber recycling, mainly focusing on the utilization of end‐of‐life tires, has heightened. This interest, is owing to the activities related to environmental protection and economic factors, which both stimulate companies to reuse the high‐quality rubber present in ground rubber scrap. In this study, the application of crosslinked butyl rubber in thermoplastic compositions of low‐density polyethylene and ground tire rubber (GTR) is presented. The static and dynamic mechanical properties and morphology of obtained products were studied. The addition of crosslinked butyl rubber to the investigated blends increased the compatibility between the low‐density polyethylene and the GTR particles. It was found that the mechanical properties of thermoplastic compositions containing higher amounts of elastomers (i.e., GTR and crosslinked butyl elastomer) displayed the same behavior, whereas the samples with GTR had worse respective parameters. Depending on their composition, the obtained new polymer blends can be applied to automotive parts, be adapted to pavement surfaces, and become parts of antivibration systems. J. VINYL ADDIT. TECHNOL., 20:237–242, 2014. © 2014 Society of Plastics Engineers     

Application of phase dispersion–crosslinking synergism on recycling commingled plastic wastes

A tetra‐component blend, consisting of low‐density polyethylene (LDPE), polyvinyl chloride (PVC), polypropylene (PP), and polystyrene (PS), was studied as a model system of commingled plastic wastes (LDPE/PVC/PP/PS, mass ratio: 70/10/10/10). Effects of chlorinated polyethylene (CPE), ethylene–propylene–diene monomer (EPDM), styrene–butadiene–styrene (SBS), and their mixture (CPE/EPDM/SBS, mass ratio: 2/2/2) on the mechanical properties and morphology of the system were investigated. With addition of several elastomers and their mixture, the tensile strength of the blends decreased slightly, although both the elongation at break and the impact strength increased. Among these elastomers, EPDM exhibited the most significant impact modification effect for the tetra‐component blends. SBS and the mixture have a good phase‐dispersion effect for the tetra‐component blend. By adding a crosslinking agent [dicumyl peroxide (DCP)], the mechanical properties of the tetra‐component blends also increased. When either SBS or the mixture was added to the blend together with DCP, the probability that the crosslinking agent (DCP) would be at the interface improved because of the phase‐dispersion effect of SBS. Therefore, more co‐crosslinked products will form between LDPE and other components. Accordingly, remarkable improvement of the interfacial adhesion and hence the mechanical properties of the tetra‐component blends occurred. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2947–2952, 2001     

Thermal and mechanical properties of uncrosslinked and chemically crosslinked polyethylene/ethylene vinyl acetate copolymer blends

Uncrosslinked and chemically crosslinked binary blends of low‐ and high‐density polyethylene (PE), with ethylene vinyl acetate copolymer (EVA), were prepared by a melt‐mixing process using 0–3 wt % tert‐butyl cumyl peroxide (BCUP). The uncrosslinked blends revealed two distinct unchanged melting peaks corresponding to the individual components of the blends, but with a reduced overall degree of crystallinity. The crosslinking further reduced crystallinity, but enhanced compatibility between EVA and polyethylene, with LDPE being more compatible than HDPE. Blended with 20 wt % EVA, the EVA melting peak was almost disappeared after the addition of BCUP, and only the corresponding PE melting point was observed at a lowered temperature. But blended with 40% EVA, two peaks still existed with a slight shift toward lower temperatures. Changes of mechanical properties with blending ratio, crosslinking, and temperature had been dominated by the extent of crystallinity, crosslinking degree, and morphology of the blend. A good correlation was observed between elongation‐at‐break and morphological properties. The blends with higher level of compatibility showed less deviation from the additive rule of mixtures. The deviation became more pronounced for HDPE/EVA blends in the phase inversion region, while an opposite trend was observed for LDPE/EVA blends with co‐continuous morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3261–3270, 2007     

Ozone cracking and flex cracking of crosslinked polymer blend compounds

Ozone cracking and flex cracking of crosslinked elastomer blends of brominated isobutylene/para‐methylstyrene copolymer (BIMSM) and unsaturated elastomers, such as polybutadiene rubber (BR) and natural rubber (NR), are studied. This saturated BIMSM elastomer, which is a terpolymer of isobutylene, para‐bromomethylstyrene, and para‐methylstyrene, functions as the ozone‐inert phase of the blend. Ozone cracking is measured by the failure time of a tapered specimen under a fixed load in a high severity ozone oven, whereas flex cracking is ranked by the De Mattia cut growth. The ozone resistance of BIMSM/BR/NR blends is compared to that of a BR/NR blend (with or without antiozonant) at constant strain energy densities. The effects of the BIMSM content in the blend, the structural variations of BIMSM, and the network chain length between crosslinks on these two failure properties, which are important in crosslinked compounds for applications in tire sidewalls, are discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2183–2196, 2007     

SBS and SEBS block copolymers as impact modifiers for polypropylene compounds

Blends of polypropylene (PP) and thermoplastic elastomers (TPE), namely SBS (styrene‐butadiene‐styrene) and SEBS (styrene‐ethylene/1‐butene‐styrene) block copolymers, were prepared to evaluate the effectiveness of the TPE type as an impact modifier for PP and influence of the concentration of elastomer on the polymer properties. Polypropylene homopolymer (PP‐H) and ethylene–propylene random copolymer (PP‐R) were evaluated as the PP matrix. Results showed that TPEs had a nucleating effect that caused the PP crystallization temperature to increase, with SBS being more effective than SEBS. Microstructure characterization tests showed that in most cases PP/SEBS blends showed the smallest rubber droplets regardless of the matrix used. It was seen that SEBS is a more effective toughening agent for PP than SBS. At 0°C the Izod impact strength of the PP‐H/SEBS 30% b/w blend was twofold higher than the SBS strength, with the PP‐R/SEBS 30% b/w blend showing no break. A similar behavior on tensile properties and flexural modulus were observed in both PP/TPE blends. Yield stress and tensile strength decreased and elongation at break increased by expanding the dispersed elastomeric phase in the PP matrix. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 254–263, 2005     

Toughening of recycled polystyrene used for TV backset

The recycled polystyrene (rPS) was toughened with ethylene‐octylene copolymer thermoplastic elastomer (POE) and high‐density polyethylene (HDPE) with various melt flow index (MFI), compatibilized by styrene‐butadiene‐styrene copolymer (SBS) to enhance the toughness of rPS for use as TV backset. The rPS/POE binary blends exhibited an increased impact strength with 5–10 wt % POE content followed by a decrease with the POE content up to 20 wt %, which could be due to poor compatibility between POE and rPS. For rPS/POE/SBS ternary blends with 20 wt % of POE content, the impact strength increased dramatically and a sharp brittle‐ductile transition was observed as the SBS content was around 3–5 wt %. Rheological study indicated a possible formation of network structure by adding of SBS, which could be a new mechanism for rPS toughening. In rPS/POE/HDPE/SBS (70/20/5/5) quaternary blends, a fibril‐like structure was observed as the molecular weight of HDPE was higher (with lower MFI). The presence of HDPE fibers in the blends could not enhance the network structure, but could stop the crack propagation during fracture process, resulting in a further increase of the toughness. The prepared quaternary blend showed an impact strength of 9.3 kJ/m² and a tensile strength of 25 MPa, which can be well used for TV backset to substitute HIPS because this system is economical and environmental friendly. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Behavior of ionomers of sulfonated styrene–butadiene–styrene triblock copolymer in polymer blends with crystalline polyolefins and as compatibilizer

The blends of ionomers of sulfonated (styrene–butadiene–styrene) triblock copolymer with two polyolefins as well as the blends of polystyrene (PSt) with two polar, oil‐resistant elastomers, i.e., chlorohydrin rubber (CHR) and chlorosulfonated polyethylene (CSPE), using the ionomer as compatibilizer were studied. The blends of the ionomer with polypropylene or high density polyethylene showed synergistic effects with respect to tensile strength. With increasing PSt content, the blends change their behavior from thermoplastic elastomer to toughened plastics. The synergism is probably because of the thermoplastic interpenetrating polymer networks formed in the blend. The blends exhibited high resistance against diesel oil or toluene. When PSt was blended with CHR or CSPE using the ionomer as compatibilizer, only 2 or 3% ionomer was needed to enhance the mechanical properties of the blends. The effect is due to the ion–polar interaction of the ionomer with the polar polymer. The enhanced compatibility of the blends by the ionomer was demonstrated by DSC and Scanning electron micrograph. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1887–1894, 2006     

Modification of recycled high‐density polyethylene by low‐density and linear‐low‐density polyethylenes

The present study investigated mixed polyolefin compositions with the major component being a post‐consumer, milk bottle grade high‐density polyethylene (HDPE) for use in large‐scale injection moldings. Both rheological and mechanical properties of the developed blends are benchmarked against those shown by a currently used HDPE injection molding grade, in order to find a potential composition for its replacement. Possibility of such replacement via modification of recycled high‐density polyethylene (reHDPE) by low‐density polyethylene (LDPE) and linear‐low‐density polyethylene (LLDPE) is discussed. Overall, mechanical and rheological data showed that LDPE is a better modifier for reHDPE than LLDPE. Mechanical properties of reHDPE/LLDPE blends were lower than additive, thus demonstrating the lack of compatibility between the blend components in the solid state. Mechanical properties of reHDPE/LDPE blends were either equal to or higher than calculated from linear additivity. Capillary rheological measurements showed that values of apparent viscosity for LLDPE blends were very similar to those of the more viscous parent in the blend, whereas apparent viscosities of reHDPE/LDPE blends depended neither on concentration nor on type (viscosity) of LDPE. Further rheological and thermal studies on reHDPE/LDPE blends indicated that the blend constituents were partially miscible in the melt and cocrystallized in the solid state.     

Radiation effects on LDPE/EVA blends

Radiation effects of low‐density polyethylene/ethylene‐vinyl acetate copolymer (LDPE/EVA) blends were discussed. EVA content in the LDPE/EVA blends was an enhancement effect on radiation crosslinking of LDPE/EVA blends, and the highest radiation crosslinking was obtained when the EVA content was reached at 30% when irradiated by γ‐ray in air. The phenomenon was discussed with the compatibility, morphology, and thermal properties of LDPE/EVA blends and found that the enhanced radiation crosslinking of the LDPE/EVA blends was proportional to the good compatibility, the increasing degree of the amorphous region's content of the LDPE/EVA blends, and the vinyl acetate content of EVA. We also found that the vinyl acetate of EVA in the blends is easily oxidized by γ‐ray irradiation in air. The possible radiation crosslinking and degradation mechanism of LDPE/EVA blends was discussed quantitatively with a novel method “step‐analysis” process of irradiated LDPE/EVA blends in the thermal gravimetric analysis (TGA) technique. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1296–1302, 2002     

Structure and properties of polyamides‐epoxidized elastomers blends

Blends of aliphatic polyamides (PA6, PA66, and PA12), containing 0–15 wt % nonepoxidized or epoxidized elastomers (statistical copolymer butadiene–styrene BS/EBS or linear block copolymer styrene–butadiene–styrene SBS/ESBS) were investigated. For PA6‐elastomer blends, taken as an example, it was shown that with increasing blending time, mechanical properties of blends increase, especially, if ESBS copolymer is used. It can be treated as an indirect sign of reactions between components. It was also found that in blends considerable changes of glass temperatures of components occur. Polyamides in blends with elastomers have smaller heats of fusion in comparison with virgin polyamides. It testifies to hindering of PA crystallization by elastomers. In some cases, significant shifts of melting points are also observed. Measurements of water contact angle show that all blends have very similar values of contact angles, which are lower than those of virgin polyamides. Elastomer content does not also affect the blend water uptake. However, it depends on the polyamide and elastomer type contrary to contact angle. Highest water uptake changes are observed in blends of PA66, especially for epoxidized elastomers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1872–1879, 2006     

Mechanical properties of recycled LDPE/EVA/ground tyre rubber blends: Effects of EVA content and postirradiation

Thermoplastic elastomers were prepared from recycled low density polyethylene [rLDPE] and virgin low density polyethylene (LDPE), respectively, ground tyre rubber (GTR), and ethylene vinyl acetate (EVA) copolymer. The amounts of the rLDPE and GTR were fixed at 40 and 30 wt %, respectively, in the formulations, whereas the LDPE and EVA contents varied each between 0 and 30 wt %. The fresh LDPE served for reduction of the melt viscosity and EVA was used for improving the elastomeric properties. Blends of different compositions (by varying the LDPE/EVA ratio) were produced by twin-screw extrusion and pelletized. Specimens were produced by injection molding and subjected to tensile and instrumented falling weight impact (IFWI) tests. To improve the mechanical performance of the blends, the injection molded specimens were electron beam irradiated at 150 kGy absorbed dose. Static tensile and hysteresis, IFWI and dynamic mechanical thermal analysis tests were performed on the specimens and the fracture surface was inspected with a scanning electron microscope. The results indicated that better rubber-like properties were achieved with increasing EVA content. Moreover, postirradiation proved to be very beneficial, especially for blends containing relative high amounts of EVA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Improving viscoelasticity and rebound resilience of crosslinked low‐density polyethylene foam by blending with ethylene vinyl acetate and polyethylene‐octene elastomer

To obtain high‐rebound resilience of crosslinking low‐density polyethylene (LDPE) foam and decrease the foam density at the same content of foaming agent, the melt viscoelasticity of LDPE with different compositions (ethylene vinyl acetate [EVA], polyethylene‐octene elastomer, and crosslinking agent) was investigated by dynamic rheology test. Then, LDPE/EVA/(polyethylene‐octene elastomer) foams with different composition ratios were produced by a continuous foaming process and investigated by the rebound resilience test. The results show that the melt viscoelasticity behavior of LDPE and its blends in the molten state possessed more melt elasticity behavior after the crosslinking was introduced. Meanwhile, the rebound resilience of LDPE foam was increased 54% at the lower foam density (0.031 g/cm³). It could meet the requirements of sports mats for high‐rebound resilience (>50%) and decrease the material cost when EVA was introduced into the foaming system. J. VINYL ADDIT. TECHNOL., 22:61–71, 2016. © 2014 Society of Plastics Engineers     

Blends of polyamide 6 and epichlorohydrin elastomers. I. Graft copolymerization in the melt blending

With the purpose of improving the mechanical properties of the polyamides, the possibility of combining polyamides with elastomers has been used. The low compatibility of the resulting blends leads to deficient mechanical properties, and therefore, it is necessary to add the compatibilizer to the mixture or to produce the compatibilizer during the melting mixture. Usually, at least one of the components must contain a reactive functional groups. In the present work, blends of polyamide 6 (PA 6) and epichlorohydrin elastomers, polyepichlorohydrin (PEPI), and the equimolar copolymer poly(epichlorohydrin‐co‐ethylene oxide), ECO, with different compositions were prepared by mechanical mixture using a Banbury‐type mixer. The blends were characterized by rheological measurements, the Molau test, elemental analysis, Infrared Spectroscopy by Diffuse Reflectance, Transmission Electron Microscopy, and X‐ray Diffractometry. The blends of PA 6 with PEPI and ECO are heterogeneous, showing a morphology of elastomer particles dispersed in the polyamide matrix. The results of rheological measurements and the Molau test indicate a graft copolymerization in the interface between the polyamide and the elastomer, PA 6‐g‐elastomer, whose concentration decreases with the elastomer content. It was found that the grafting of PEPI and PA 6 changed the diffraction pattern of PA 6. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1827–1833, 1999     

Thermoplastic elastomers from rubber and recycled polyethylene: chemical reactions at interphases for property enhancement

Recycled low density polyethylene (R‐LDPE) has been reactively compatibilized with butadiene rubber (BR) by using small additions of reactive polyethylene copolymers and reactive BRs to produce thermoplastic elastomers (TPEs). TPEs were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), rheology measurements, wide‐angle X‐ray scattering (WAXS) and mechanical testing. WAXS results show that the presence of BR and reactive modifiers does not completely prevent the crystallization of R‐LDPE during the TPE formation. Depression of the melting point has been found in all cases. Also in all cases, compatibility is provided by formation of interfacial layers. The best mechanical characteristics are obtained for R‐LDPE + BR blends compatibilized with poly(ethylene‐co‐acrylic acid) (PE‐co‐AA) and polybutadiene terminated with isocyanate groups (PB‐NCO) for PB‐NCO = 7.5 wt% per PB and COOH/NCO ratio = 1/1. The stress at break and elongation at break are respectively improved by 31 % and 63 %. The PB‐NCO modifier participates in co‐vulcanization with BR in the rubber phase and reacts at the interface with the PE‐co‐AA dissolved in the polyolefin phase. As a result, the amorphous phase of R‐LDPE is dissolved by the rubber phase and a morphology with dual phase continuity is formed, assuring an improvement of mechanical properties of TPEs. Copyright © 2004 Society of Chemical Industry     

Reactive blending of polyamides with epoxidized elastomers

Melt blending of aliphatic polyamides (PA6, PA66, PA12) with epoxidized and nonepoxidized elastomers (SBS, BS, PB) was investigated. IR and rheological studies have shown that epoxidized elastomers can simultaneously react both with polyamides and within their own phases during melt blending. Relative intensity of both processes is the main factor, which determines structure and properties of blends. SEM observations indicated that use of epoxidized elastomers improves blend homogeneity and decreases mean size of dispersed elastomer phase in comparison with nonepoxidized elastomers. Mechanical properties of epoxidized elastomers based blends are generally better with respect to similar blends with nonepoxidized elastomers. They depend on blend composition and type of polyamide and elastomer. Elastomer addition decreases tensile strength of all systems but in some cases, a considerable rise of impact strength was measured. Epoxidized SBS block copolymer was found to be the most effective modifier, especially with respect to PA6 and PA12. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Miscibility,morphology and mechanical properties of rubber‐modified biodegradable poly(ester‐urethanes)

Biodegradable, lactic acid based amorphous poly(ester‐urethane)s (PEU) were modified with poly(L‐lactic acid‐co‐ϵ‐caprolactone‐urethane) elastomer (P[LA/CL]U) by melt blending. The phase separation of P(LA/CL)U elastomer with three different ϵ‐caprolactone (CL) compositions (CL content 30, 50, and 70 mol %) and the mechanical properties of the resulting impact‐modified linear and branched PEU were investigated. The amounts of P(LA/CL)U elastomer in the PEU blends were 10, 15, 20, and 30 wt %. Dynamic mechanical thermal analysis (DMTA) of the blends with P(LA50/CL50)U and P(LA30/CL70)U elastomers revealed separate glass transition temperatures for rubber and matrix, indicating phase separation. No phase separation was found for P(LA70/CL30)U elastomer. The effect of mixing rate and temperature during processing on composite properties was tested by blending P(LA30/CL70)U rubber with PEU under various processing conditions. Impact modification studies were also made with two P(LA30/CL70)U elastomers having different amounts of functional groups. The influence of end‐functionalization and cross‐linking on mechanical properties was investigated in blends containing PEU and 15 wt % of these elastomers. Scanning electron microscopy (SEM) showed the morphology to change dramatically with increase in the degree of cross‐linking in the rubber. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1074–1084, 2000     

Effect of butyl rubber type on properties of polyamide and butyl rubber blends

Polyamide‐12 was blended with butyl rubber, bromobutyl rubber, and chlorobutyl rubber with and without a sulfur curing system. Mechanical properties for dynamically vulcanized blends generally exceed those made with no vulcanization. Chlorobutyl‐containing blends prepared by dynamic vulcanization have higher tensile strength and elongation at break values in comparison to those made from other butyl rubbers. For a variety of polyamide/rubber blends made by dynamic vulcanization, there is very little effect of rubber percentage unsaturation and Mooney viscosity on the mechanical properties of the blends. In chlorobutyl‐containing blends prepared by dynamic vulcanization, the swelling index values attributed to the rubber portion decrease as rubber content decreases, and it is likely that the polyamide phase completely surrounds the rubber particles at compositions exceeding approximately 25% polyamide. Swelling index results can be correlated with elongation at break values for similar blends. The results of differential scanning calorimetry suggest that the polyamide phase is not a neutral component in high shear mixing with butyl rubbers with or without curing agents. Rheological studies indicate strong non‐Newtonian behavior for all blends of polyamide‐12 with butyl rubbers. Scanning electron microscopy on polyamide‐12/butyl rubber blends indicates compatibility for butyl rubbers in the order of chlorobutyl > bromobutyl > butyl rubber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1423–1435, 2004     

Compatibilizer in waste tire powder and low‐density polyethylene blends and the blends modified asphalt

With the increasing ratio of waste tire powder (WTP) to low‐density polyethylene (LDPE), the hardness and tensile strength of the WTP/LDPE blends decreased while the elongation at break increased. Five kinds of compatibilizers, such as maleic anhydride‐grafted polyethylene (PE‐g‐MA), maleic anhydride‐grafted ethylene‐octene copolymer (POE‐g‐MA), maleic anhydride‐grafted linear LDPE, maleic anhydride‐grafted ethylene vinyl‐acetate copolymer, and maleic anhydride‐grafted styrene‐ethylene‐butylene‐styrene, were incorporated to prepare WTP/LDPE blends, respectively. PE‐g‐MA and POE‐g‐MA reinforced the tensile stress and toughness of the blends. The toughness value of POE‐g‐MA incorporating blends was the highest, reached to 2032.3 MJ/m³, while that of the control was only 1402.9 MJ/m³. Therefore, POE‐g‐MA was selected as asphalt modifier. The toughness value reached to the highest level when the content of POE‐g‐MA was about 8%. Besides that the softening point of the modified asphalt would be higher than 60°C, whereas the content of WTP/LDPE blend was more than 5%, and the blends were mixed by stirring under the shearing speed of 3000 rpm for 20 min. Especially, when the blend content was 8.5%, the softening point arrived at 82°C, contributing to asphalt strength and elastic properties in a wide range of temperature. In addition, the swelling property of POE‐g‐MA/WTP/LDPE blend was better than that of the other compalibitizers, which indicated that POE‐g‐MA /WTP/LDPE blend was much compatible with asphalt. Also, the excellent compatibility would result in the good mechanical and processing properties of the modified asphalt. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

化学交联PE-LD/SBS共混物的形状记忆效应研究

分别用3种不同苯乙烯含量的苯乙烯-丁二烯共聚物(SBS)与低密度聚乙烯(PE-LD)混合制成共混物,采用过氧化苯甲酰(BPO)为引发剂,使共混物发生化学交联形成网状结构,对交联共混物的交联度进行了分析,测试了交联共混物的拉伸强度与断裂伸长率,探讨了交联共混物的形状记忆效应。结果表明,在PE-LD/SBS共混物中,随着BPO含量的增加,共混物的交联度增大;BPO含量固定时,随着SBS中丁二烯含量的增大共混物的交联度增大;随着交联度的增加,共混物的拉伸强度与断裂伸长率均下降;当BPO含量为0.5 %～1.5 %时,交联共混物具有良好的形状记忆效应。     

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.