Preparation of halloysite nanotubes supported 2-mercaptobenzimidazole and its application in natural rubber

To improve the antioxidative efficiency of 2-mercaptobenzimidazole (MB) and strengthen the interaction between halloysite nanotubes (HNTs) and natural rubber (NR), HNTs supported 2-mercaptobenzimidazole (HNTs-s-MB) was prepared by reacting MB with chlorosilane modified HNTs (m-HNTs). FTIR, XPS and TGA confirmed that MB was chemically bonded onto the surface of HNTs. HNTs-s-MB could be homogeneously dispersed in the NR matrix and there was a strong interfacial interaction between HNTs-s-MB and NR, leading to the better mechanical performances of NR/HNTs-s-MB nanocomposites than those of NR/HNTs nanocomposites. Based on the measurements of the thermo-oxidation activation energy of NR/HNTs-s-MB and NR/m-HNTs/MB nanocomposites containing equivalent antioxidant component, it was found that the antioxidative efficiency of HNTs-s-MB was superior to that of the corresponding low molecular MB owing to the much lower migration and volatility of HNTs-s-MB than those of MB.