Studies of conventional sulfur vulcanization of SBR rubber: Analysing the reaction products from thermal degradation of the accelerator by means of MCC-IMS technique

• Published in: Polymer testing 2020-10, Vol.90, p.106715, Article 106715
• Main Authors: Pietrzak, Dominik, Bieliński, Dariusz M., Henneicke, Daniela
• Format: Article
• Language: English
• Subjects: Crosslink density; Crosslink structure; MCC-IMS analysis; Mechanical properties; Rubber; Volatile organic compounds (VOCs); Vulcanization
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/j.polymertesting.2020.106715

A combination of knowledge on curing process of rubber mixes with novel methods of chemical analysis, a new unconventional approach to analysis of rubber vulcanization is presented in this study. Six SBR samples containing various N-tert-butyl-2-benzothiazole sulfenamide (TBBS) accelerator: sulfur ratios (within) the range of conventional (CV) sulfur vulcanization system were studied using multi-capillary column ion mobility spectrometry (MCC-IMS) technique. For these analysis, calibration/dilution curves were established. Moreover, data from MCC-IMS were correlated with other parameters of the rubber vulcanizates – their crosslink density and structure as well as their tensile strength and modulus at elongation. For such comparison, one of the reaction products from thermal decomposition of TBBS, benzothiazole was selected. Furthermore, the concentration of benzothiazole released during the vulcanization process corresponded well with the crosslink density of the rubber vulcanizates studied. It was even possible to calculate the crosslink density from the concentration of benzothiazole determined by MCC-IMS, using Boltzmann fitting curve. The presented results could be an important contribution in understanding the mechanisms occurring during rubber vulcanization, demonstrating a new approach to testing and evaluation of the process. •Developed calibration/dilution line linked with MCC-IMS is suitable for chemical analysis of vulcanization process of rubber.•MCC-IMS instrument is able to follow chemical markers from sulfur vulcanization of rubber.•Concentration of benzothiazole released during vulcanization process allows comparison with various rubber properties.•Benzothiazole and crosslink density correlation indicate the chemical process that occurs during the crosslinking.