Effect of filler particle characteristics on yield stress and viscosity of fresh sulfur composites

Abstract

The amount and properties of fillers greatly affect the workability of sulfur composites. In addition, modified sulfur has fluidity only above approximately 115 °C, and its rheology may depend on the temperature. This study aimed to mainly quantify the effects of mixing temperature and filler particle characteristics on the yield stress and viscosity of fresh sulfur composites by applying suspension rheology theory. Sulfur composites containing mineral fillers, such as different blends of fly ash and Portland cement, were examined. The test results revealed that the yield stress of the sulfur composites was influenced by both the type and volumetric ratio of fillers, whereas the viscosity was governed by the specific surface area of filler particles. At 140 °C, the sulfur composites attained a higher yield stress and viscosity than at 120 °C. In addition, the intrinsic viscosity of the sulfur composites was dependent on the filler type and not on its volume ratio. The sulfur composites were well described by conventional yield and viscosity models commonly applied for suspension materials, when the filler volume ratio was less than 30%.

Keywords

• Modified sulfur
• Fresh sulfur composite
• Rheology
• Filler particle characteristic
• Mixing temperature
• Krieger–Dougherty model