The article presents the results of studies of the properties of samples of powder phthalonitrile binding with different particle-size distribution. Microstructural studies of the phthalonitrile binder have been carried out. The main technologies for combining polymer binding with reinforcing fillers are described. Examples of calculating the ranges of values of the weight characteristics of prepregs are given, taking into account the possible spread of the surface density of the reinforcing filler and the selected range of the mass content of the binder. The fundamental possibility of using a powder phthalonitrile binding to obtain PCMs using prepreg technology is shown.