Influence of cross-linked system on morphology and properties of thermoplastic vulcanizates based on isotactic polypropylene and ethylene propylene diene monomer

Abstract

Thermoplastic vulcanizates (TPVs) based on isotactic polypropylene (iPP) and oil-free/ oil-extended ethylene propylene diene monomer (EPDM) rubber were prepared by dynamic vulcanization. Their rheological and tensile properties as well as morphological peculiarities were examined and compared with those of uncured blends. Vulcanization was performed using two types of cross-linking agents: phenolic resin and sulfuraccelerating systems. Dynamic vulcanization was shown to change the melt viscosity of oil-free and oil-extended iPP/EPDM blends. These changes were found to depend on both rubber content and type of vulcanizing agent. For identical composition, the melt viscosity of TPVs cured by sulfur system was higher than that of blends cured by phenolic resin system (PRS). Dynamic vulcanization by PRS decreased tensile properties of TPVs in comparison with sulfur vulcanization. Morphology of iPP/EPDM blends studied by atomic force microscope was found to be dependent on the ratio of components, type of elastomer, and nature of vulcanizing system.

Investigation on the mechanical properties and oil resistance of sulfur cured nitrile rubber/hydrogenated nitrile butadiene rubber blends

“…[ 26‐29 ] The sulfur curing system was selected in this work to achieve better co‐crosslinking network and get better comprehensive properties. [ 30‐35 ]…”

Super-hydrophobic and super-oleophilic surface based on high-density polyethylene/waste ground rubber tire powder thermoplastic elastomer

“…Due to these unique characteristics, TPEs show great importance in applications such as automotive, electrical cable, and construction. [17][18][19][20][21] Nowadays, the usage of waste ground rubber tire (WGRT) has attracted great attention because of increasing number of vehicles. 22,23 Van Beukering and Janssen 24 reported that about 800 million tires were discarded all over the world every year, which was estimated to increase by 2% annually; and Sienkiewicz et al reported that approximately 1.4 billion unit tires were produced around the globe every year.…”