Sol-gel–synthesized nano zinc oxide (ZnO) is introduced as a cure activator in carbon black (CB)– and silica-filled natural rubber (NR) composites. The performance of sol-gel–synthesized nano ZnO was systematically compared with conventional ZnO for various filled NR composites in terms of cure, mechanical, aging, and thermal properties. At a filler loading level of 40 parts per hundred parts of rubber (phr), only 1 phr nano ZnO provided a better cure rate index and tensile strength as compared with 5 phr conventional ZnO in CB-filled NR composites. On the other hand, at a 40 phr filler loading level, the cure and mechanical properties of the 1 phr nano ZnO cured NR/silica composite were comparable with the properties of the 5 phr conventional ZnO cured NR/silica composite. At the same filler loading level, both 1 phr nano ZnO and 5 phr conventional ZnO had a similar effect on the thermal stability of NR/CB and NR/silica composites. As a whole, 1 phr sol-gel–based nano ZnO could be used as an efficient cure activator instead of 5 phr conventional ZnO in CB- and silica-filled NR composites with successive reduction of ZnO level.

溶胶-凝胶合成的纳米氧化锌（ZnO）作为硫化活化剂被引入炭黑（CB）和二氧化硅填充的天然橡胶（NR）复合材料中。在固化，机械，老化和热性能方面，系统地比较了溶胶-凝胶合成的纳米ZnO与常规ZnO在各种填充NR复合材料中的性能。在填充量为每100份橡胶40份（phr）的填充量下，与CB填充的NR复合材料中的5 phr常规ZnO相比，只有1 phr纳米ZnO提供了更好的固化速率指数和拉伸强度。另一方面，在40 phr填料填充量下，1 phr纳米ZnO固化的NR /二氧化硅复合材料的固化性能和机械性能与5 phr常规ZnO固化的NR /二氧化硅复合材料的性能相当。在相同的填充量下，1 phr纳米ZnO和5 phr常规ZnO对NR / CB和NR /二氧化硅复合材料的热稳定性都有类似的影响。总体而言，在CB和二氧化硅填充的NR复合材料中，随着ZnO含量的不断降低，基于1 phr溶胶-凝胶的纳米ZnO可以代替5 phr常规ZnO用作有效的固化活化剂。