Preparation of carboxylated nitrile butadiene rubber/fly ash composites by in-situ carboxylate reaction

Fly ash (FA) is a byproduct of thermal power stations, which causes increasing environment pollution in the last decade. The incorporation of FA would deteriorate the performance of polymer composites even modified by silane coupling agents. Thereby, the bulk utilization of FA in polymer industry is still a challenge in the world. In this work, by in-situ carboxylate reaction between carboxyl groups of carboxylated nitrile butadiene rubber (XNBR) and FA particles, an immobilized rubber layer is formed on the surface of FA particles, resulting in a better interface adhesion. As a consequence, the tensile strength of XNBR/20FA composite reaches 23.19 MPa, about 44.0% larger than pure XNBR. Even if the incorporation of FA is up to 40phr, the tensile strength is still about 20.60 MPa, about 28.0% larger than pure XNBR, which opens a new approach to lower polymer product cost and solve the environment pollution.