An experimental study was conducted to investigate the morphology, thermal and mechanical properties of recycled polyolefin blends with different prehistory modified with ethylene propylene rubber (ethylene-propylene diene monomer (EPDM)) using the differential scanning calorimetry (DSC), wide angle X-ray scattering, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope and mechanical methods. The efficiency of the modification was investigated as a function of the modifier content in the range from 7 wt% to 15 wt%. DSC results show that the single polymers are not clean material and contain some quantity of another polyolefins. In the processing and exploitation conditions, there is an increase in imperfect crystals in the postconsumer waste polypropylene. FTIR provides clear evidence about the oxidative processes and mechanical destruction during exploitation and blending. The obtained results proved that the technological and postconsumer wastes could be successfully reused as blends by the addition of EPDM.

Composites of polypropylene and carbon black were melt compounded by a vibration-assisted process. For comparison, conventional extrusion was also used for preparation of the same composites. A throughput of the vibration-assisted process was established to be higher than that of conventional extrusion. Microscopic images of the extrudates demonstrated better dispersion of the fillers when the vibration force field was applied. The mechanical properties and viscoelastic behavior of the composites were studied and the results were discussed in the context of the reinforcing action of the fillers and the higher level of polypropylene chain scission accompanying the vibration-assisted process.

Blends of isotactic poly(propylene) and low‐density polyethylene with different composition ratios were prepared through direct melt compounding on a twin‐screw extruder. The specimens with various geometric configurations were injection‐molded using a gas counterpressure process, using blends to which 0.5 wt.‐% of a blowing agent was added. The influence of blend composition and specimen geometry on the structure and morphology of the samples was investigated by SEM and WAXS. The thermal behavior of the blends was analyzed by DSC. It was found that the morphology of each region depended on the composition ratio and specimen geometry.magnified image