Sulfur Free Crosslinking of Epdm Composites via Silane Grafting and Silica Incorporation.

This study aims at evaluating and developing an environmental-friendly and sulfur-free cured Ethylene Propylene Diene Monomer (EPDM) composites. Silane grafted EPDM (SiEPDM) composites incorporated with silica was prepared via a solvent-free, one-step reactive mixing process. The silane grafting and silica filler bonding were characterized using FTIR and XPS. The mechanical properties (tensile, tear and hardness) of the developed composites were examined. The fracture morphology was observed using an environmental scanning electron microscopy. The rheology and thermomechanical properties were evaluated by using a rotational rheometer and dynamic mechanical analyzer. Notably, a robust bonding between silica and the grafted silane was established, yielding a crosslinking network within the composite structure. This phenomenon was substantiated by the observed gel efficiency and rheology behavior. Consequently, a pronounced augmentation of up to 75% in tensile strength and 29% in tear strength were observed in the optimized SiEPDM-silica composites, distinguishing them from their EPDM-silica counterparts. The introduction of paraffin oil contributed to enhanced processibility; however, it was concomitant with a reduction in gel efficiency and associated mechanical properties. Furthermore, subsequent UV weathering test unveiled that the SiEPDM-silica composites exhibited the highest levels of residual tensile strength and modulus, indicative of their exceptional UV stability. This article is protected by copyright. All rights reserved.