A vulcanizable rubber composition comprises an interpenetrating or ionic network (IPN)-promoting resin. The resin comprises side chain functional groups along the resin backbone, which, in the presence of an additive material, form the connections that make up the IPN. In one embodiment, such material is ZnO. A method for forming the rubber composition comprises, in a productive step, mixing the product of the non-productive step, the zinc oxide, and a resin derived from maleic anhydride. The zinc oxide and the resin are simultaneously added to the composition during the productive mixing stage. The rubber composition can be cured and incorporated in a tire component, such as, a tread.