A TERNARY nanocomposite containing natural rubber, butadiene rubber, and styrene-butadiene rubber (NR/BR/SBR BLEND) was prepared in 25/25/50 (phr), on which the effect of adding carbon black, nano clay )C15A), and nano-silica was examined. Rheometric, tensile, and hardness measurement tests were performed on the prepared samples. The nano silica-containing sample showed an inhibitory effect in curing, while the modified nano clay-containing sample showed an accelerating effect on the curing process. The results revealed that the presence of nano-silica caused higher elongation at break. TEM analysis was performed from cross-linked samples to ensure the exfoliation of nano additives in the matrix. The results confirmed the suitable distribution and dispersion of the nanoparticles in the composite samples.

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.

Polypropylene (PP) as a linear resin has low melt strength. The melt strength of polymer is the main feature for the success of low density extrusion foam. Use of a high melt strength such as branched PP (Br-PP), is required to achieve large volume expansion by preventing cell coalescence and gas loss. In this paper, the effects of long chain branched polypropylene on melt elasticity and volume expansion in the extrusion process of PP TERNARY BLENDs are investigated. The equilibrium creep compliance (Je0) and damping factor (tan d) of melts were evaluated as melt elasticity index by oscillation rheometry. To setup the extrusion foaming process, the Haake 25 L/D single-screw extruder was improved by design and manufacturing to a special 38 L/D screw with a long mixing zone. Extrusion temperatures were optimized to reach a stable foaming process. The consistency of process pressure as a measure of foam extrusion system stability was evaluated. The cell population density and expansion ratio were determined for foam samples. The effects of the blowing agent (BA) on the amount of pressure build-up were measured at various branched PP levels in the BLEND. The experiments showed that, by increasing the branched PP, Je0 increases, and tan d decreases, which is an evidence of improved melt elasticity. The maximum expansion ratio for the BLENDs was achieved at about 55% of branched PP resins and 20% of B.A. The results also showed that, by increasing the branched PP, the cell population density increases to a maximum of 7.5×106 (cell/cm3) and no significant increase was observed at higher branched PP levels.