Composites Developed by the Reaction of Elemental Sulfur with Biologically Derived Fats and Oils

Human civilization’s modern infrastructure relies mainly on cement and petrochemical products. However, the production of these building materials have harmful ecological effects such as green gas emissions, therefore intensifying the need to develop alternative, sustainable structural materials from renewably sourced or waste material precursors. The work presented herein investigates various biomass derived resources that serve as the olefin source for reaction with elemental sulfur, another abundant waste source, via inverse vulcanization to form high strength composites competitive with that of traditional building materials. Chapter one reviews various techniques that have been developed and executed in an effort towards lignin valorization and the production of bio-oils as biofuel additives or intermediates. These methods include pyrolysis, hydrothermal liquefaction, and catalytic delignification, all of which accomplish efficient lignin depolymerization, a crucial step in the valorization of the abundant, underutilized biomass material. Chapter two reports terpenoid-sulfur composites with pozzolan additives possessing favorable thermal and mechanical properties when compared to traditional building materials. Chapter three reports the reaction of lignin oil, produced via a previously reported thermal solvolysis technique, with elemental sulfur to yield a durable composite competitive with that of traditional material buildings and previously reported lignin-sulfur cements. Chapter four expands on the research presented in chapter three by investigating the effects the comonomer ratio and reaction temperature has on the mechanical strength and thermal properties of lignin oil-sulfur composites. Chapter five reports high strength composites made from the reaction of elemental sulfur, sunflower oil, and wastewater sludge from dissolved air flotation (DAF) water treatment. The composites reported in chapter five displayed compressive and flexural strengths competitive with that of ordinary Portland cement (OPC) as well as previously reported composites prepared via the reaction of elemental sulfur and plant oils or animal fats.