Algae oil (409 mg) was heated to 170 °C with stirring in a 25 mL round bottom flask. After 5 minutes, the algae oil turned from a viscous orange liquid to dark brown and free flowing liquid. Elemental sulfur (409 mg) was added slowly over 5 minutes to keep the mixture at approximately 170 ºC. A heat gun was used to melt sulfur adhering to the upper walls of the flask. After 30 minutes the viscosity increased and stirring was slowed to ensure continual mixing. Approximately 5 minutes after the increase in viscosity, the reaction mixture could not be stirred. After a further 10 minutes at 170 °C, the flask was removed from the oil bath and allowed to cool to room temperature. After 1 hour of cooling the material had vitrified into a dark brown rubber. The synthesis was carried out in triplicate. The average amount of product formed in these reactions was 458 mg of solid product and 146 mg of unreacted oil (obtained by extraction into ethanol). Some unreacted sulfur was embedded in the polymer (see below) and some was lost to sublimation during the reaction. The isolated copolymer was then characterized by scanning electron microscopy (SEM), simultaneous thermal analysis, dynamic scanning calorimetry, 1 H NMR spectroscopy and powder X-ray diffraction, as detailed in the Supporting Information.