Thraustochytrids are a valuable source of diverse triglycerides, composed of both saturated and unsaturated fatty acid components. This study demonstrated the production of such oils and a novel method to separate polyunsaturated triglycerides from monosaturated and unsaturated triglycerides. This process converted the polyunsaturated triglycerides into novel, sulfur-rich polymer composites. The unreacted saturated components were easily recovered through extraction with ethanol, for potential use as biodiesel precursors. Future studies will focus on upscaling the algae oil production and novel uses of the sulfur polymers reported in this study. With increasing interest in the synthesis and applications of sulfur-rich polymers, this study is an important step forward in the sustainable production of the triglyceride comonomer.