STUDY OF DYNAMIC VISCOSITY OF EPOXY COMPOSITIONS USING NANO- AND MICRO-FILLERS

Abstract

The article investigates the effect of nano- and micro-fillers on the dynamic viscosity of epoxy composites based on DER
331 resin. Carbon nanotubes (NT) and CARBON BLACK N220 nanosoot were used as nanofillers at a content of 0.01 to 0.1
mas.%, and chromium oxide Cr₂O₃ powders (20 μm) and silicon carbide SiC (40 μm) at a content of 5 to 20 wt.% as microfillers.
Rheological studies were carried out on an NDJ-1S viscometer at four shear rates (6, 12, 30, 60 rpm).
The results showed that the introduction of fillers increases the viscosity of composites compared to pure resin, with
microfillers having a greater effect due to their higher volume fraction. Nanofillers significantly increase the viscosity of epoxy
compositions than NTs due to their tendency to aggregation. All compositions exhibit pseudoplastic properties: viscosity
decreases with increasing shear rate. The mechanism of changes in rheological properties is explained by the model of floc
formation and destruction (for nanofillers) and hydrodynamic interaction of particles (for microfillers).
The optimal filler content was established: 0.05 mas.% for nanoparticles and 10 mas.% for microparticles, which can
provide an improvement in mechanical properties without significant deterioration in processability. The results obtained are
of great importance for the development of technologies for applying protective coatings in shipbuilding.