Effect of triethylene glycol bis(3‐tert‐butyl‐4‐hydroxy‐5‐methylphenyl)propionate on structure and mechanical properties of nitrile butadiene rubber/clay nanocomposites

Abstract

AbstractClay modification by organic ammonium salts has been widely introduced in rubber/clay nanocomposites, but it is inapplicable in the polar rubbers to achieve high performance due to bad dispersion and poor compatibility. In this work, gel‐compounding method was utilized to prepare nitrile butadiene rubber (NBR)/clay nanocomposite, and then a hindered phenol antioxidant, triethylene glycol bis(3‐tert‐butyl‐4‐hydroxy‐5‐methylphenyl)propionate (AO‐245) with various contents, was mechanically blended to enhance the interactions in the nanocomposites. The elongation at break increases while the Shore A hardness, permanent set and stress at 100% or 300% strain decrease by adding AO‐245 into the nanocomposites. By adding only 5 phr AO‐245 in the nanocomposite, the tensile strength and elongation at break increased from 18.3 MPa and 521% to 20.5 MPa and 646%, respectively, which resulted from the repeated destruction/construction of the hydrogen bonds between AO‐245 and NBR. At high AO‐245 content, both clay networks and AO‐245 aggregate networks coexist in the nanocomposite, and the excess AO‐245 in the NBR matrix can form a separated phase leading to a new internal friction peak.