Rheological properties of phenolic resin as a liquid matrix precursor for impregnation of carbon–carbon composites with respect to conditions of the densification process

The aim of this study was to determine the basic rheological parameters of phenolic resin as a possible liquid matrix precursor for impregnation of carbon–carbon composites. Typical pseudo-plastic behaviour was observed. The dependencies of viscosity on concentration, temperature and time were measured. On the basis of results of viscosity measurements the impregnation conditions were proposed. To achieve maximal efficiency of densification process, the high carbon yield and low viscosity of resin are necessary. Newtonian behaviour of resin solutions with mass fraction up to 0.65 at 90 °C was confirmed. This value of mass fraction is compromise solution between high carbon yield and low viscosity of resin.