The effect of addition of silica on the parameters of isothermal crystallization of polypropylene has been investigated. It
was found that the covering of the silica surface by a layer of low-density polyethylene leads to a deactivation of the filler
regarding the positive effect on the polypropylene crystallization rate parameters. Cross-linking of the surface polyethylene
layer results in a stronger attachment of the modifying polymer to the filler surface and the deactivation effect of the silica
surface modification is more pronounced.