Simultaneously Improved Curing, Mechanical, Antioxidative Properties and Reduced ZnO Loading of Silica Filled NR Composites by Incorporation of Low-cost Crude Carbon Dots via Conventional Melt-milling Method

Rubbers or elastomers play an important role in hi-tech technology and civilian daily life because of their unique and strategical properties. Generally, the rubber additives are essential components for rubbers’ practical application. Nowadays, developing novel multifunctional additives has attracted increasing research attention. In this work, low-cost crude carbon dots (CCDs) were used as multifunctional additives for natural rubber/silica system (without any additional modification) through industrial compatible melt-mixing method. The results revealed that the CCDs could disperse well in the NR/silica system, and they could not only endow the rubber compound with excellent anti-aging capability due to CCDs’ radical scavenging activity because of their plenty of nitrogen-containing species, but also improve the curing rate and mechanical performance of the rubber composite. Also, the CCDs could reduce the rolling resistance of the rubber composites (tanδ value at 7% strain of the rubber composite could be decreased by 34%), which is promising for the application of energy-saving tire industry. Lastly, the addition of CCDs could effectively reduce the ZnO dosage by at least 40% in the rubber composite without deteriorating its performance. Overall, this work provides valuable guidance to develop novel cheap yet effective additives for the elastomer.