Synthesis of antioxidant for natural rubber using new heterogeneous catalytic system

In this paper, a new type of heterogeneous catalytic system was devised for the synthesis of 4,4′-bis-(2,6-di- t -butylphenol), (hereinafter referred to as bisphenol-VN). The properties of the catalytic system were studied using SEM–EDS and transmission electron microscope methods. The results have demonstrated the presence of hydrophobic phenolate layer on the surface of the catalytic system, which provides high catalytic activity in the synthesis of bisphenol-VN. The bisphenol-VN obtained was taken for structural analysis by SEM, IR and MS-HPLC methods to prove the purity of the product. Simultaneously, the bisphenol-VN was also tested in natural rubber to enhance the physical–mechanical properties. The use of bisphenol-VN extends the oxidation induction time of natural rubber by three times in the comparison with the commercial antioxidant 6PPD.