Crosslinking of Fluoroelastomers Using a Bio-Based Polyphenolic Compound

Abstract

Fluoroelastomers, especially FKM, are usually crosslinked with bisphenol derivatives, most commonly bisphenol AF, which pose ecological and health concerns, including endocrine disruption and reproductive disorders. To address these drawbacks, we aimed to identify an alternative crosslinking system that could deliver comparable cure characteristics and physicomechanical properties. In pursuit of this goal, we investigated phloroglucinol (PG), a bio-based polyphenolic compound, as a potential alternative curative to achieve rheological and mechanical properties comparable to those obtained with the conventional bisphenol AF (BPAF) curing system. Using PG as the curative and benzyl tri-phenyl phosphonium chloride (BTPPC) as an accelerator, the optimum cure properties were determined using rheometric studies with a rubber process analyzer (RPA). The dosages of PG as a curative and BTPPC as a phase-transfer catalyst, respectively, were optimized to have optimum cure characteristics as well as mechanical properties comparable with the BPAF system. The MTT assay investigation validates that the cytotoxicity of PG (IC50 = 863.6 ± 0.06 μM) is much lower than that of BPAF (IC50 = 73.04 ± 0.07 μM).