Effects of silane coupling agents on the properties of bentonite/nitrile butadiene rubber nanocomposites synthesized by a novel green method

Abstract

Effects of different silane coupling agents on the mechanical strength, tribological properties, thermal behaviors, swelling properties and rheological properties of bentonite (Bent)/nitrile butadiene rubber (NBR) nanocomposites were explored. The nanocomposites were fabricated with an innovative green method in NBR latex. The composition of the nanocomposites was determined by Fourier transform infrared spectroscopy (FT-IR). The intercalated/exfoliated structure and the dispersion of Bent in rubber matrix were characterized with X-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM). It is revealed that different functional groups from the silanes were effective to the properties of the nanocomposites mainly because of their different interactions with the rubber matrix. Mercaptopropyltrimethoxysilane (MPTMS) showed attractive effects on mechanical modulus, tribological properties and swelling properties. Incorporation of bis-[3-(triethoxysilyl)propyl]tetrasulfide (TESPT) resulted in the highest elongation at break. With octadecyltrimethoxysilane (OTMS), the degradation temperature of the nanocomposite was noticeably elevated due to its “barrier effect”.