Rhodanine‐chitosan hydrogel as a novel antioxidant for acrylonitrile‐butadiene rubber composites

Abstract

AbstractRhodanine‐chitosan (RC) hydrogel is examined as a novel antioxidant for acrylonitrile‐butadiene rubber (NBR) composites. RC is added to NBR with different proportions (1, 2 phr) and compared to the commercial 2,2,4‐trimethyl‐1,2‐dihydroquinoline polymer (TMQ) antioxidant. Physico‐mechanical properties including tensile strength, elongation, and modulus are also studied. It is found that NBR composite containing 2 phr of RC has the most favorable mechanical properties. The formed composites were subjected to thermo‐oxidative aging at 90°C for 1, 3, and 5 days. It is noticed that NBR composite containing 2 phr of RC is the most resistant to aging. Swelling properties and crosslink density are also determined. Composite containing 2 phr of RC has also higher crosslink density than the other prepared composites. The formed NBR composites containing both TMQ and RC are characterized by Fourier transforms infrared (FTIR), thermogravimetric analysis (TGA), and field emission scanning electron microscope (FESEM). The effect of aging on chemical structure of the composite and on surface morphology are also studied. It is found that the chemical structure of the composites containing 2 phr of RC is not affected by aging.Highlights Rhodanine‐chitosan (RC) is assessed as a new antioxidant for acrylonitrile‐butadiene rubber (NBR). RC is incorporated into NBR at two different concentrations: 1 and 2 phr. Mechanical, thermo‐oxidative aging, and swelling properties are evaluated. Thermal stability, Fourier transforms infrared and field emission scanning electron microscope are studied. Vulcanizates with 2 phr of RC show the most superior properties.