Abstract

This paper describes the effects of various alkali metal and alkaline earth metal compounds, as well as walnut shell ash (WNS ash), on the cure characteristics (ts2, tc90) of a chlorobutyl rubber (CIIR)-based heat resistance truck inner tube compound. We observed that CIIR-F (KOH) has a very high scorch safety and a very slow cure. As it is a strong base with a high pH (13.84), it cures very slowly. Despite having a pH of 10.6, a ts2 of 6.36, and a tc90 of 18.84 min, CIIR-D (CaCO3) cures faster than CIIR-A (blank). The ts2 and tc90 values for CIIR-A (blank) were 6.55 and 18.88 min, respectively. Except for CIIR-D (CaCO3), all of the materials used to have higher scorch safety (ts2) and optimum cure time (tc90) in rheometer than CIIR-A (blank). CIIR-C (BaCO3) performed nearly as well as a blank. This study revealed that the trend of cure characteristics (ts2, tc90) in rheometer and Mooney scorch (t5) in Mooney viscometer not only depends on pH but also depends on ionic radius, ionization enthalpy and oxidation number of alkali metal and alkaline earth metal and the type of compound of alkali metal and alkaline earth metal. (c) 2022 Kingfa Scientific and Technological Co. Ltd. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).