Due to rapid increase in consumption rate of EPDM in rubber industry in the last decade, recycling and reusing of this rubber have attractive and extensive studies. Blending with the other polymers can be an efficient method for reusing of recycled EPDM. In this study, ternary blends of polypropylene (PP), high density polyethylene (HDPE) and mechano-chemical devulcanized EPDM (D-EPDM) were prepared using a laboratory twin-screw extruder. Three levels of D-EPDM (20, 40, 60 wt%) at constant concentration of HDPE (20 wt%) were used. Sulphur dynamic vulcanization was applied on the samples. Mechanical properties such as: tensile properties, compression set, hardness, impact resistance and morphology of samples were studied and compared to samples containing virgin EPDM. Tensile strength and compression set decreased with increase in both D-EPDM and EPDM content in the ternary blend. Dynamic vulcanization improved the mechanical properties and its effect on the samples containing D-EPDM was more  onsiderable. The dominant morphology of both ternary blends was the separate dispersion of HDPE and EPDM (or D-EPDM) in the PP matrix. The D-EPDM formed droplets dispersed in PP matrix similar to the virgin EPDM.

A series of ethylene-propylene-2-ethylidenebicyclo [2.2.1] hept.5-ene terpolymers (EPDM) have been prepared using a VOCl3/Al2Et3Cl3 catalyst under various AIN ratios and diene concentrations via solution polymerization and characterized by FTIR, Mooney viscosity (ML1+4, 125°C), and thermal gravimetery analyzing. The polymerization yield was seen to increase with augmentation of the AIN ratio and diene concentration and pass through a maximum of about 200gr polymer/g V. On the other hand, Mooney viscosity decreases with an increase in the two latter parameters. Increasing solvent to monomer ratio increased polymerization yield while it decreased Mooney viscosity. Accordingly, an optimum amount of solvent to monomer ratio (4:1 in mass) was found. One advantage of these polymer systems is that all the measured Tg property remained constant around 232-240 K in the range of incorporated ethylene and diene concentration. It has been observed that when AIN ratio decreases and diene concentration increases, there is an increment in ethylene incorporation (40-60%), and the results have been compared with the characteristics of two commercial EPDMs (Herlen 563, Vistalon 7500).

Melt free-radical grafting reactions between ethylene-propylene-dieneterpolymer (EPDM) and glycidyl methacrylate (GMA) were investigated in a batch mixer (170°, C, 60rpm). Effect of dicumylperoxide (DCP) initiator and GMA functionalizing monomer concentrations was studied on the grafted EPDM characteristics. Titration results indicated an increase in the graft degree (GD) and gel content (GC) values with increasing DCP concentration as a result of increasing primary free radical concentration and strengthening cross-linking side reaction. FTIR spectrums confirmed that GMA functionalities have been grafted onto EPDM with appearing carbonyl (C=O) peak. After that, the resultant EPDM-g-GMA was used as compatibilizer in PS(polystyrene)/EPDM/ PA6 (polyamide6) ternary blends. The effect of rubbery compatibilizer on the blend morphology and mechanical properties was studied. The ATR-FTIR spectra of ternary blends, etched to remove unreacted PA6, demonstrated that the compatibilizing reactions occurred during melt blending. By investigating the SEM micrographs it was revealed that the EPDM-g-GMA compatibilizer at the concentration range of 5 wt. % to 15 wt. % changed the size and type of the blend morphology from separated dispersed to multicore-shell morphology. The finest morphology was achieved by using 7. 5 wt. % EPDM-g-GMA. Also, the presence of compatibilizer up to 7. 5 wt. % could improve the tensile modulus, yield stress and impact strength, but a decreasing trend was observed at higher concentration of the compatibilizer.

Soon at the beginning of the last century after it was discovered that carbon black is an active filler in rubbers, it became one of the most important components in manufacturing of rubber products. In this work, the effect of carbon black's type and loading and the structure of rubbers on rate constant and activation energy of the vulcanization were studied by the rheometer. The rubbers for this purpose are ethylene propylene diene monomer (EPDM), with natural rubber (NR), and butadiene rubber (BR). The overall rate of vulcanization is calculated from the kinetic expression of first order vulcanization. The results have showed that carbon black reduces activation energy in all rubbers and increases overall rate of vulcanization. In this case N330 reduces the activation energy and increases the overall rate of vulcanization rather than N660. On the other hand, this research showed that vulcanization rate of EPDM/BR is less than EPDM/ NR. This is as the same trend as the number of allylic hydrogens in the repeat unit of these rubber chains.

The principal objective of this study was to explore the compatibility of a blend of two synthetic elastomers viz., ethylene-propylene-diene rubber (EPDM) and chlorobutyl rubber (CIIR). Various commercial grades of EPDM were blended with a specific grade of CIIR at different proportions. The mechanical properties such as tensile strength, tear strength, ageing resistance, etc. were studied. On the basis of the observed physical properties, two particular grades of EPDM were found to be compatible with CIIR. Differential scanning calorimetry and scanning electron microscopy confirmed the results. Chlorosulphonated polyethylene was added as a compatibilizing agent to overcome the phase separation of the other two incompatible grades of EPDM in blending with CIIR. The results revealed that the addition of compatibilizer greatly improves the compatibility and thereby the properties of the blends.

Varying amounts of a high molecular weight poly(1-hexene) (PH, Mv=1. 7×106 Da) are substituted for EPDM in an iPP/iPP-g-MA/EPDM blend (weight ratio: 76: 4: 20) and mechanical properties as well as phase morphology of the blends are studied and compared. The results show that by substituting the entire EPDM with PH, the tensile strength-at-break increases from 18. 7 to 21. 1 MPa, elongation-at-break increases from 15. 5% to 370. 8%, and impact strength increases from 6. 4 to 50. 1 kJ. m-2. Dynamic mechanical thermal analysis (DMTA) of the blends proved their immiscibility and SEM analysis confirmed these findings by showing droplet-matrix morphologies. Studying the creep behavior of the samples shows that the blends containing PH have more creep so that by substituting all EPDM in the blends with PH, the permanent deformation increases from 0. 425% to 0. 505%. According to the results, PH is introduced as a candidate for improving the impact properties of iPP/iPP-g-MA/ EPDM blend.