Sulfur-based polymeric materials were obtained from surplus feedstock; elemental sulfur; and sustainable algae oil, Botryococcene, via inverse vulcanization. Reactions of elemental sulfur and Botryococcene at 185 °C produce polymeric materials with various weight ratios of sulfur and Botryococcene (5:5 to 9:1), depending on the feed ratio. In this study, these polymers have been characterized from several aspects using spectral analysis, thermoanalysis, and electrochemical analysis. When the composition of sulfur is more than 70 wt %, the polymer contains a residual sulfur element not incorporated in the polymer chains. The sulfur-based polymers can be pressed into intended shapes when heated at 120 °C. The polymers could serve as active materials for Li−S batteries. This investigation of structure and properties provides basic information for future applications.

This study prepared an elastic material with an infrared (IR)-transmitting property based on the structural features of algae oils. The bulk copolymerization of elemental sulfur and unsaturated hydrocarbons yields sulfur-based polymeric products, in a process termed inverse vulcanization. The inverse vulcanization of algal oils, such as squalene and botryococcene, forms highly cross-linked products owing to the multiple reaction sites along the long unsaturated backbone. Based on this structural feature, a combination of the algal oils and plant-based short-chain monoterpene compounds (d-limonene and β-myrcene) was investigated to provide a suitable cross-linking density for achieving an elastic function. Inverse vulcanization of squalene and β-myrcene produced an elastic material with an IR-transmitting property. The developed material served as a varifocal lens in the IR region that responds to external elongation forces. From the viewpoint of sustainability, it is meaningful that the material was produced from sustainable feedstocks (algae and plant oils) and a surplus feedstock (sulfur).