Effect of Feeding Strategy on the Mechanical Properties of PP/Recycled EPDM/PP-G-MA Blends

Abstract

In this work, thermoplastic elastomers based on polypropylene (PP) and recycled ethylene-propylene-diene monomer (r-EPDM) blends with polypropylene-graft-maleic anhydride (PP-g-MA) as modifier (0 to 8wt.%) were prepared by melt compounding via twin-screw extrusion followed by injection molding. In particular, the effects of material composition and feeding strategies were studied. The morphological and mechanical properties of the blends were investigated by using scanning electron microscopy (SEM), tensile, flexural, impact, density and hardness tests. The results indicate that good dispersion and compatibility between PP and r-EPDM particles was obtained and that incorporation of r-EPDM leads to significant increase in PP impact strength. Finally, the feeding order of each component in the extruder was found to modify substantially the final morphology of the blend, thus having ad irect influence on their mechanical properties.

Effect of Feeding Strategy on the Properties of PP/Recycled EPDM Blends

“…Also, the feeding sequence during polymer blending has significant influence due to the dependence of final blend properties on the mixing quality achieved in the extruder. As reported in our previous study (Mahallati and Rodrigue, 2014) and also shown here, feeding the r-EPDM first not only produces smaller particles, but also better interaction with the matrix as possible thermo-mechanical regeneration of the crosslinked rubber can occur (Macsiniuc et al, 2010;2012). This gives more freedom for the rubber molecules on the surface of the particles to entangle with the macromolecular chains of the matrix and improve dispersion/stress transfer.…”

“…were studied for af ixed r-EPDM content of 50 %wt. (Mahallati and Rodrigue, 2014). From this work, it was found that coupling agent addition is not necessary for this optimized system (processing conditions).…”

“…This helps in reducing costs, but not to improve mechanical performance on am acroscopic level. Nevertheless, several works have been published on the addition of GTR as ad ispersed elastomer phase in PP to improve impact strength (Grigoryeva et al, 2005;Karger-Kocsis et al, 2013;Kim et al, 2003;Lee et al, 2007;Mahallati and Rodrigue, 2014;Naskar et al, 2002;Nevatia et al, 2002;Oliphant et al, 1993;Shanmugharaj et al, 2005;Xin et al, 2009).…”

Review of the Reclaiming of Rubber Waste and Recent Work on the Recycling of Ethylene–propylene–diene Rubber Waste

“…The use of recycled EPDM in polypropylene (PP) as a thermoplastic elastomer was studied. 110 The results indicated that good dispersion and compatibility between PP and recycled EPDM was obtained and incorporation of recycled-EPDM led to significant improvement in the PP impact strength. Effect of recycled-EPDM rubber on the mica-filled EPDM rubber compounds was measured.…”

Thermoplastic vulcanizate nanocomposites based on polyethylene/reclaimed rubber: A correlation between carbon nanotube dispersion state and electrical percolation threshold

“…According to the literature, studies have been mostly focusing on the effect of reclaimed rubber (RR) content or its modification on the curing, morphological, mechanical, rheological, melting/crystallization, and degradation properties of thermoplastic/RR blends . But the literature still lacks information on the electrical conductivity of polyolefin/RR compounds, especially in presence of conductive nanomaterials.…”