Partial replacement of EPR by GTR in highly flowable PP/EPR blends: Effects on morphology and mechanical properties

Abstract

This research analyzes the effect of ground tire rubber (GTR) and a novel metallocene-based ethylene-propylene copolymer (EPR), with high propylene content, on the morphology and mechanical behavior of ternary polymer blends based on a highly flowable polypropylene homopolymer (PP). The PP/EPR blends morphology, with very small domains of EPR dispersed in the PP matrix, indicates a good compatibility among these materials, which leads to a significant improvement on elongation at break and impact strength. The incorporation of EPR on the rubber phase of thermoplastic elastomeric blends (TPE) based on GTR and PP (TPE GTR ) has a positive effect on their mechanical performance, attributed to the toughness enhancement of the PP matrix and to the establishment of shell-core morphology between the rubber phases. The mechanical properties of the ternary blends reveal that TPE GTR blends allow the upcycling of this GTR material by injection molding technologies.

Processing and Mechanical Properties of Highly Filled PP/GTR Compounds

“…This indicates relatively weak interfacial interactions between the matrix and the rubber particles. A similar effect was observed by Lima et al for PP/EPR compounds [ 27 ]. However, such effects were not observed for the PP/GTR50-P sample ( Figure 18 b).…”

“…In recent years, the possibility of mass use of GTR as a filler for thermoplastic polymers [ 22 , 23 , 24 , 25 ], including polypropylene [ 26 , 27 , 28 ], has been observed. Basso [ 29 ] described the effect of GTR grain size on the selected functional properties (hardness and roughness) of homo-polypropylene compounds.…”

Phase morphology, mechanical, and thermal properties of fiber-reinforced thermoplastic elastomer: Effects of blend composition and compatibilization

“…65 Low crystallinity level of R80 (45.6%) suggests a decrease in the overall crystallinity with decreasing rHDPE content supports the decreasing trend of tensile strength and tensile modulus (Table 5) with increasing filler content (softer nature). 19 Overall, the different blend compositions had negligible difference in their temperatures of melting and crystallization, as well as crystallinity degree which is in agreement with previous reports. 20 According to the crystallinity and impact strength results, it can be concluded that the higher toughness (Figure 8) is mainly the results of the developed phase morphologies and interfacial interactions.…”

“…17 To solve this problem, the addition of elastomers is the most common method to increase the impact strength (toughness) increasing the amount of energy absorbed before rupture. 18 To this end, several copolymers, such as ethylene-propylene-diene monomer (EPDM), 19 styrene-butadiene-styrene (SBS), 20 and styrene-ethylene-butylene-styrene, 21 have been proposed for impact modification. Lima et al 22 claimed that EPDM tends to coat the recycled tire particles surface providing a soft interface improving compatibility with PP.…”

A sustainable molding process for new rubber products from tire recycling

“…Polymer-rubber composites have been obtained mainly from elastomers (natural and synthetic rubber) or thermoplastics (polyethylene, polypropylene, and polyvinyl chloride). 21 Latest developments have preferred thermoplastic matrices for making ternary 22 or binary 23 blends also for foams 24 and without using virgin materials. 25 GTR has also been used to improve ductility and damping capacity of recycled wood plastic composites.…”