High scission of butadiene rubber vulcanizate under thermo-oxidation

• Published in: Polymer degradation and stability Vol. 167; pp. 292 - 301
• Main Authors: Xie, Yanling, Hassan, Adeel Ahmad, Song, Pan, Zhang, Zhen, Wang, Shifeng
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.09.2019; Elsevier BV
• Subjects: Butadiene; Butadiene rubber; Chromatography; Cleavage; Crosslinking; Crosslinking polymerization; Degradation; Evolution; Fourier transforms; Liquid chromatography; Oxidation; Recycling; Rubber; Soybean oil; Soybeans; Degradation; Butadiene rubber; Oxidation; Recycling; Soybean oil
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2019.07.015

The cross-linked structure of butadiene rubber (BR) vulcanizate presents a challenge to the environmentally benign recycling of waste tires. The high scission of BR vulcanizate was realized by thermo-oxidation in the presence of soybean oil. The effects of the mass ratio of rubber to oil (2:1, 1:1, 2:3, 1:2 and 2:5), oxidation time (0.5, 1, 2, 3, 5, 7 h) and temperature (130, 140 and 160 °C) on degradation were investigated by measuring the evolution of the sol fraction and cross-link density of degraded BR. The results showed that the BR vulcanizate was degraded effectively under thermo-oxidation (140 °C, 3 h), resulting in the highest sol fraction of 70.7%. Furthermore, the structural evolution of degraded BR was studied by gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR). Oxidation, scission and recombination of the cross-linked network of BR occurred simultaneously during thermo-oxidation. The scission of the BR vulcanizate was enhanced by suppressing the recombination of BR chains in the presence of soybean oil. •High scission of BR vulcanizate was realized by thermal oxidation.•The highest sol fraction of BR vulcanizate is over 70%.•Oxidation, scission and recombination of BR occurred simultaneously.