Exploring inverse vulcanisation mechanisms from the perspective of dark sulfur

Abstract

The build-up of elemental sulfur waste poses problems such that only the advancement of process and product design might act as a solution. Inverse vulcanisation, a process for the generation of high sulfur content polymeric materials may be one such resolution. However, a complete understanding of how these materials form is yet to be fully agreed in this emerging field. Herein is an investigation into the understanding of ‘dark sulfur’ – amorphous, unreacted sulfur, not incorporated into the polymer backbone – in an attempt to understand further the formation mechanisms behind inverse vulcanisation. This research posits theories regarding polymer formation, thermal rearrangement, and the actions of OH to control the degree of product crosslinking, in relation to the quantity of sulfur unreacted into the polymer structure. The detriments and benefits of this dark sulfur in relation to application and general usage are also investigated, showing that a high content of dark sulfur may encourage planktonic bactericidal activity, while also promoting safety considerations from generated species such as hydrogen sulfide and carbon disulfide, concluded as components of this dark sulfur.