Effects of Ethylene-Propylene-Diene Monomers (EPDMs) with Different Moony Viscosity on Crystallization Behavior, Structure, and Mechanical Properties of Thermoplastic Vulcanizates (TPVs)

Abstract

Moony viscosity of ethylene-propylene-diene monomers (EPDMs) can have effect on the crystallization dynamics, structure, and properties of EPDM/polypropylene (PP)-based thermoplastic vulcanizates (TPVs). TPVs with two different Moony viscosities are prepared via a twin-screw extruder, respectively. Crosslinked EPDM with lower Moony viscosity has a higher crosslinking density and the nucleation effect of its crosslink point improves the crystallization ability of PP in TPV, leading to PP phase crystallization at higher temperatures. For TPV with an EPDM of higher Moony viscosity, it has higher crystallinity and the EPDM phase crystallized earlier. Synchrotron radiation studies show that the EPDM with low Moony viscosity has no obvious crystalline structure, and the prepared TPV has an obvious phase separation structure, while the TPV with higher Mooney viscosity of the EPDM does not exhibit obvious phase separation, indicating that the longer EPDM chains have better compatibility with PP in TPV, also evidenced by the almost disappearance of the PP glass transition peak in TPV, from the dynamic mechanical analysis. The longer EPDM chains in TPV provide more physical entanglement and better interaction with PP molecules, resulting in a stronger strain hardening process, longer elongation at break, and higher tensile stress in TPV.

A Review of EPDM (Ethylene Propylene Diene Monomer) Rubber-Based Nanocomposites: Properties and Progress

“…As a result, there is potential for the development of new analytical processes for elastomers in the future, such as EPDM, as well as other applications that utilize machine learning tools to validate and predict the development of new elastomer blends, including [ 177 , 178 , 179 ]. Furthermore, in the development of thermoplastic elastomers (TPVs), the mixtures EPDM/PP, the higher crystallinity of the PP in the TPV blend, the higher Mooney viscosity, as well as the better compatibility between EPDM and PP, result in higher tensile strength and elongation at break, which are enhanced by the crystals present in EPDM [ 180 ]. Therefore, EPDM is an elastomer with a long way to go in terms of new applications relating to viscosity and rheology, as in this case for the application of TPV.…”

A integração do conhecimento científico e a produção sustentável de termoplásticos vulcanizados a partir de resíduos de pneus

“…O aumento no teor da fase termoplástica resulta em elevado módulo elástico, e quando o maior teor é a borracha vulcanizada observa-se melhora na elongação na ruptura do TPV. Estes materiais são utilizados nas indústrias automobilísticas em substituição a borracha convencional, reduzindo o impacto ambiental (Bouchart et al, 2008;Innes et al 2023;Ponsard-Fillette et al, 2005;Song et al 2023).…”

“…Desde então, muitos estudos se concentraram no uso de pares de borracha e plástico compatíveis para preparar TPVs com domínios de borracha finos e boas propriedades (Yao et al, 2016ª, 2016b. Os TPVs produzidos pelos polimeros EPDM (terpolimero de Etileno-Propileno-Dieno) e PP (polipropileno) têm compatibilidade tecnológica, polímeros apolares (Innes et al, 2023;Song et al, 2023).…”