Model samples of aerosil with preliminary finished surface polymerization-modified with (meth)acrylates with given length and density of grafted polymer chains have been studied. From thermodynamic cycles the enthalpies, Gibbs energies, entropies of adhesion of grafted polymer layer to the finished surface and to the polymer matrix are calculated. On the base of obtained thermodynamic results the coiled conformations of grafted polymer chains and difference of the structure of polymer layer from the structure of the polymer synthesized without a filler are assumed. Therefore the heat effect of the interaction of such polymerization-modified filler with the polymer matrix of the same nature is not equal to zero. Obtained thermodynamic data are discussed in the combination with the data on absorption of (meth)acrylates from their solutions on aerosil and data on thermodynamics of interaction of components of filled systems.