Devulcanisation of ground rubber tyre by novel ternary deep eutectic solvents.

This study aims to optimize the parameters in thermo-sonic devulcanisation of ground rubber tyre (GRT) with the help of three novel ternary deep eutectic solvents (TDESs). Ultrasonic frequency and time were varied between 37 and 80 kHz and 25–60 min, respectively. Whereas, heating temperature and time intervals were ranged from 25 to 200 °C and 0–60 min. Through one factor at a time (OFAT) analysis and response surface methodology (RSM) software modelling, the study shows that 37 kHz sonication for 60 min and thermal treatment at 180 °C for 55 min were the optimum conditions, resulting in 75% devulcanisation (%Dvul). At these conditions, devulcanisates were further analysed by thermogravimetric analyser (TGA), Fourier transform infrared spectroscopy (FTIR), swelling behaviour and Horikx curve to verify the occurrence of devulcanisation. These additional analyses verify that the intensity of sulphur bridges reduced and negligible changes in degradation temperature as well as the amount of main chain scission were experienced. These evidences demonstrate selective scission of sulphur-bridges as well as the high potential that polymeric properties were being retained compared to typical reclamation process. Unlabelled Image • TDES with a high number of α-Hs showed greater GRT devulcanisation. • 1 h sonication and heating at 180 °C for 55 min was optimum for devulcanisation. • Di-ethyl-ammonium chloride-based TDES gave the best response. [ABSTRACT FROM AUTHOR]