Inverse Vulcanized Sulfur Polymer Composites From Poultry‐Industry Products and Lignocellulosic Biomass Waste

High sulfur‐content materials (HSMs) are emerging as alternatives to conventional structural materials because they can be prepared from abundant industrial and agricultural byproducts while exhibiting excellent mechanical properties. In this work, a base binder, GFS 90 (90 wt.% sulfur, 5 wt.% chicken fat, and 5 wt.% sunflower oil), is reinforced with eggshell powder (ES) and feather meal (FM) from poultry industry waste, as well as lignocellulosic fillers including peanut hulls (PH) and sawdust (SD). The resulting composites exhibit negligible water uptake (< 0.3 wt.%, 24 h immersion) and mechanical strengths ranging from 15.3 to 36.2 MPa. The peanut‐hull composite (GFS 90 ‐PH) reaches 36.2 ± 2.0 MPa, more than double the 17 MPa compressive strength benchmark for ordinary Portland cement used in residential construction. Thermal analysis reveals sulfur‐dominated transitions with melting temperatures near 115°C–118°C and glass transitions between −34°C and −38°C. Additive incorporation modestly improves resistance to thermally induced mass loss, with decomposition onset temperatures ranging from 209°C to 221°C. These results demonstrate that agricultural and poultry products reinforce sulfur‐rich polymer composites, yielding mechanically robust and water‐resistant materials that rival conventional cement‐based construction materials.