Thermal Degradation of Natural Rubber Vulcanizates Reinforced with Organomodified Kaolin Intercalates

Abstract

In this study, Natural Rubber Vulcanizates (NRV) reinforced with organomodified kaolin was developed. The NRV were subjected to thermal degradation to ascertain its suitability for high-temperature automotive applications. Kaolin intercalation was achieved using derivatives of Rubber seed oil (Hevea brasiliensis) and Tea seed oil (Camellia sinensis) in the presence of hydrazine hydrate as co-intercalate. The developed Natural Rubber Vulcanizates were characterised using Thermogravimetric Analysis (TGA), Fourier Transform Infrared (FTIR) Spectroscopy and Scanning Electron Microscopy (SEM). FTIR spectra obtained for the organomodified natural rubber vulcanizates revealed the presence of carbonyl groups at bands 1564cm-1 and 1553cm-1 which is an indication of organomodified kaolin intercalation within the Natural Rubber matrix for kaolin intercalates of Rubber seed oil and Tea seed oil respectively while no value was reported for the Natural Rubber vulcanizates obtained from the pristine kaolin filler. TGA results indicated that NRV developed from kaolin intercalates of Rubber seed oil (RSO) with onset degradation and final degradation temperatures of 354.2°C and 601.3°C were found to be the most thermally stable of the Natural Rubber Vulcanizates investigated. The SEM micrograph revealed that the kaolin nanofillers in Rubber Seed Oil modified Natural Rubber Vulcanizates were well dispersed as compared to that of Tea Seed Oil modified Natural Rubber Vulcanizates.