EPDM crosslinking from bio-based vegetable oil and Diels-Alder reactions

The aim of this work was to study and develop a green process of plasticization and crosslinking of an EPDM matrix with a thiofuran based coupling agent. For this purpose, tung oil, composed of around 80 wt% of α-eleostearic acid, was used as both plasticizer and thermal crosslinker. Due to the low compatibility and weak interactions between vegetable oils and the EPDM matrix, the 2-furanmethanethiol (derived from the food industry) was used as a di-functional compatibilizing agent. The 2-furanmethanethiol was successfully grafted by a thiol-ene reaction onto both the tung oil and the EPDM matrix. The formulation was thermally treated in order to crosslink the EPDM matrix and the tung oil through expected Diels-Alder reaction. The reactions were evidenced by liquid 1H NMR spectroscopy analysis. The crosslinked sample was characterized by different mechanical tests. The sample properties were also compared with the ones of an EPDM crosslinked by dicumyl peroxide (DCP) and plasticized by mineral oil.