Investigation of nanoparticle effects on rheology of particulate filled suspensions

Achieving a flawless solid composite propellant requires proper processability of its corresponding filled polymer slurry. In other words, the optimal rheological properties of highly filled suspensions after mixing process, ensure its transfer to the mold and complete filling of complex geometries. In this dynamic study, after adding molybdenum disulfide nanoparticles to the model materials, rheological properties of the obtained suspensions have been investigated.In order to study the effect of molybdenum disulfide nanosheets on the rheological behavior of the suspensions, polyethylene glycol matrix and glass beads, as model, with particle distribution of 60 to 103 microns were employed.Single-layer and multi-layer molybdenum disulfide nanosheets with thickness of 50 to 100 nm was obtained after acid washing, oxidation and heat shock of raw molybdenum disulfide. Then, after preparation of suspensions containing 10-40 vol% glass beads, the effect of obtained molybdenum disulfide (less than 0.1 vol% of the matrix) on the rheological properties of the mixture was studied. Results of frequency sweep and temperature sweep tests showed that complex viscosity of the suspensions had a significant decrease with increasing nanoparticles, while simultaneously, storage modulus was fixed and loss modulus was increased. The test also confirmed this. Finally, the dynamic shear flow test demonstrated that the dynamic viscosity also decreased significantly after addition of nanoparticles.