Zirconium phosphate modified by polydopamine as anti-aging filler for improving thermal oxidative aging resistance of nitrile butadiene rubber

The migration of commercial rubber antioxidants causes significant environmental pollution; thus, environmentally friendly antioxidants are receiving increasing attention in rubber production. Herein, we prepared a green anti-aging composite filler called ZPa via an in situ intercalation polymerization procedure of polydopamine (PDA) on zirconium phosphate ( α -ZrP) for realizing the enhancement of mechanical performance and aging resistance in nitrile butadiene rubber (NBR). Different from commercial antioxidants, the biocompatibility of α -ZrP and PDA made ZPa non-toxic and harmless to the environment. Results showed that PDA increased the interlayer spacing of α -ZrP and promoted its dispersion in matrix. The best reinforcement effect of the composite filler on NBR can be achieved with 5 phr of ZPa. The tensile strength of ZPa/NBR increased by 51% compared to the neat NBR. The outstanding free radical capture capability and the barrier function of ZPa greatly enhanced the ability of NBR to resist aging. The mechanical properties after aging of ZPa-5/NBR were 64% and 21% higher than those of the neat NBR in tensile strength and elongation-at-break values, respectively. The present work also exhibited that ZPa/NBR showed powerful thermal oxidative stability. In brief, ZPa enabled NBR highly competitive for mechanical performance and anti-aging property, which is expected to be utilized in the field of “green” rubber. Graphical Abstract