Functionalization of a liquid natural rubber by iron-mediated radical chloro-nitration and its thermal decomposition

This study presents the functionalization of liquid natural rubber (LNR) by iron-mediated radical chloro-nitration over the LNR backbone, resulting in a chloro-nitro compound of liquid natural rubber (Cl-N-LNR). The chloro-nitration was prepared by a reaction of LNR with iron(III) nitrate nonahydrate and iron(III) chloride in an organic solvent. The structure of the obtained product was confirmed by using Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), and carbon-13 nuclear magnetic resonance (13C NMR), which showed the existence of chloro-nitro groups in the Cl-N-LNR chain. The degree of functionalization with a nitro group is 13.4 mol units of Cl-N-LNR. The thermal degradation was determined by the thermogravimetric analysis (TGA) method. As a result, the kinetic parameters for the degradation of Cl-N-LNR were calculated in the range from 40 to 330 °C. The half-life of Cl-N-LNR was found to be about 33.0 years. © 2024 Vietnam Academy of Science and Technology and Wiley-VCH GmbH.