On the potential of clay with respect to conventional fillers (CB and SiO₂) for ENR compatibilized NR/EPDM vulcanizates Available to Purchase

In an internal mixer, natural rubber / ethylene propylene diene monomer (NR/EPDM) rubber blend was compounded with onium modified montmorillonite (organoclay), and the mixture was then vulcanized using a traditional crosslinking system (sulphur-based crosslinker). In this work, a compatibilizer consisting of epoxidized natural rubber (ENR) with 50 mol percent epoxidation (ENR 50) in 10 phr (parts per hundred rubber) was utilised. Two commercial fillers were utilised for comparison: silica (SiO₂, grade: vulcasil-S) and carbon black (CB: grade-N330, high abrasion furnace (HAF)). On a Monsanto MDR2000 Rheometer, cure properties were measured. The lowest values for torque minimum (M_l), torque maximum (M_h), scorch time (t_s2), and optimum cure time (t_c90) were found in the organoclay (OC) filled vulcanizate. Tensile and tear strength properties of the NR/EPDM composites were determined during mechanical testing. In comparison to SiO₂ and CB filled composites, the improvement of elongation at break, tensile strength and tear strength characteristics in OC filler-filled vulcanizates was much developed. OC demonstrated the maximum stiffness in terms of reinforcing effectiveness, followed by SiO₂ and CB loaded composites. The failure mechanism of the resulting NR/EPDM composites has been changed as compared to the gum vulcanizates, according to scanning electron microscopy.