. The introduction of epoxide groups onto the grafted PMMA further enhanced the inter- molecular interactions as additionally indicated by the increased plasticity and the decreased swelling ratio in ASTM oil No. 1 and IRM 903. The polarity changes also affected the wettability of the materials as demonstrated by the lower contact angles of water and diethylene glycol droplets on the polymer films. The modified rubbers con- taining both grafted PMMA and epoxide groups offer much better thermal stability and oil resistance, compared to vir- gin NR. Therefore, these functionalized rubbers can poten- tially be applied to various applications especially as compatibilizers in immiscible blends of NR with polar materials such as silica and nanoclay.