Abstract

The thermal stability is one of the most important properties of insoluble sulfur (IS). The filling oil directly influences the thermal stability of IS. The effect of basic organic nitrogen compounds and ash less stabilizers used in filling oil were studied to improve the thermal stability. The data showed that the thermal stability decreased with an increase in the basic nitrogen compound content in the filling oils. When the basic nitrogen content in the filling oil was lower than 20μg/g, the thermal stability of IS was not changed. Ash less stabilizers including phenols, esters, carboxylic acids and their mixtures could increase the thermal stability of IS. When different types of phenols were mixed, the thermal stability of IS was greater than 91%. The thermal stability of IS reached 95.54% when 0.2wt% of oleic acid was used.

Keywords: Insoluble sulfur; Basic nitrogen compounds; Thermal stability; Ash less stabilizer