Crosslinking Kinetics of Blends of Ethylene Vinyl Acetate and Ground Tire Rubber

The copolymer ethylene vinyl acetate (EVA) and blends of EVA and ground tire rubber (GTR) with different compositions are prepared in the presence and absence of dicumyl peroxide (DCP) as a crosslinking agent. The crosslinking kinetics is investigated through oscillatory disc rheometry (ODR) and differential scanning calorimetry (DSC). The crosslinking kinetics is found to be dependent on the amount of GTR in the EVA/GTR blends; the partially crosslinked GTR phase acts as a physical barrier, slowing down the EVA crosslinking rate. Furthermore, activation energies (Ea) and reaction order (n) values suggest that the crosslinking reactions are not restricted to the EVA bulk, but can also occur to some extent at the EVA/GTR interface.