Functionalization of a liquid natural rubber by ironmediated radical chloronitration and its thermal decomposition

Abstract

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 con- firmed 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 CI-N-LNR chain. The degree of functionalization with a nitro group is 13.4% mol units of CI-N- LNR. The thermal degradation was determined by the thermogravimetric analysis (TGA) method. As a result, the kinetic parameters for the degradation of CI-N-LNR were calculated in the range from 40 to 330°C. The half-life of CI-N-LNR was found to be about 33.0 years.