Recyclable Composites Prepared From Animal Coproducts and Industrial Waste Sulfur

Pursuing sustainable and environmentally friendly materials has become a significant objective in materials science, particularly flame retardants and construction materials. This dissertation explores the development and evaluation of novel composites and high sulfur-content materials (HSMs) as potential alternatives to conventional, environmentally harmful materials. Chapter one reviews recent advancements in environmentally benign flame-retardant additives, highlighting the potential of bio-derived phenols, polysaccharide derivatives, and greener phosphorus sources. The review discusses how green additives can enhance the flame retardancy, thermal stability, and smoke suppression properties of various polymers while addressing the challenges and future directions in the field. Chapter two investigates the production and properties of SunBG90, a HSM composed of brown grease, sunflower oil, and elemental sulfur. This chapter emphasizes its environmental benefits, including low water and energy consumption and reduced CO2 emissions compared to Ordinary Portland Cement (OPC). Standardized ASTM and ISO tests demonstrate that SunBG90 exhibits superior water absorption and thermal conductivity, suggesting its potential as an eco-friendly alternative to OPC for structural applications. Chapter three explores the impact of various environmental stresses on the strength development of SunBG90. The study determines significant thermomorphological transitions and the formation of metastable γ-sulfur in hexane-exposed samples through differential scanning calorimetry and powder X-ray diffraction analyses. Compressive strength tests reveal that SunBG90 retains high strength under most conditions, with elevated temperatures causing the most notable decrease in strength. These findings provide valuable insights into the durability and suitability of SunBG90 as an OPC alternative. Chapter four focuses on enhancing the flame resistance of SunBG90 by incorporating various flame retardants (FRs). The study evaluates the effectiveness of inorganic, phosphorus-based, brominated, and nitrogen-containing FRs, with organic additives significantly improving fire resistance. A blend of SunBG90 with 20 wt. % TBBPA achieves the highest flame resistance classification (94V-0) and demonstrates improved abrasion resistance and bond strength. This research highlights the potential of HSMs to meet stringent fire safety standards while maintaining or enhancing their mechanical properties.