Synthesis of nano zinc oxide and its effect on the cure characteristic and properties of natural rubber vulcanizates

Abstract

Abstract In this work, nano ZnO was synthesized by a simple method using a polymeric substance as a dispersing agent. Characterization of the synthesized ZnO by XRD and SEM confirmed the ZnO was nanometric in size and had a wurtzite structure. The synthesized nano ZnO was used as an activator for natural rubber vulcanization. Different amount of ZnO, 1, 2 and 3 phr, was investigated in the rubber formulation and compared to convention ZnO at a typical amount (6 phr). The sample with 3 phr nano ZnO showed the lowest curing induction time with the highest (ML-MH) at all studied temperatures. Furthermore, the rubber sample with 3 phr ZnO achieved the best properties, i.e., crosslink density, rebound resilience, and hardness compared to the rubber sample with 6 phr conventional ZnO. Interestingly, the properties of rubber sample with 2 phr nano ZnO were probably equivalent and comparable to that of 6 phr conventional ZnO. Thus, it suggested that the synthesized nano ZnO could replace the convention ZnO as an activator for rubber vulcanization even at a lower amount.