A golf ball comprising a core, an outer cover layer, and, optionally, an intermediate layer disposed between the core and the outer cover layer is provided. The core, intermediate layer, or cover layer includes a composition formed from a base polymer blend, a crosslink initiator, and at least one additive. The outer cover layer may comprise a polyurethane or polyurea composition. The base polymer blend preferably includes two or more rubber materials. The additive has at least one C—O—B linkage, the carbon in the linkage being a secondary or tertiary carbon and is selected from the group consisting of boranes, borates, boronates, borinates, heterocylic compounds having at least one boron atom as a ring member, boron-containing organosulfides, salts of such additives, and metal salts, organometallic salts, and non-metal salts of boron complexes.