Water absorption and tensile properties of ground tire rubber/epoxy composites: effect of surface treatment

This paper investigates the surface treatment effect of ground tire rubber (GTR) on the water absorption and tensile properties of aged GTR/epoxy composites. The GTR was treated using 10 wt-% NaOH solution and 1 wt-% stearic acid (SA) in acetone. The results showed that the GTR addition increased the water absorption and decreased the tensile strength and elastic modulus of epoxy composites. In dry condition, compared to the untreated GTR, the tensile strength of the treated GTR decreased by about 4.8% and 2.9% for the NaOH- and SA-treated GTR, respectively. Nevertheless, the addition of treated GTR increased the elastic modulus of epoxy composites by about 8.4% and 6.0% for the NaOH-and SA-treated GTR, respectively. For the aged epoxy, the tensile strength and elastic modulus decreased further due to the matrix plasticisation and degradation of the interface GTR/epoxy strength. It was found that the SA-treated GTR has better performance than the NaOH-treated GTR.