A fractal model of a filled polymer is proposed. the model allows us to est
imate quantitatively the volume of an interphase, to take into account geom
etrical factors influencing the character and the interphase adhesion level
, and to predict the mechanical strength of interfacial bonds. this makes i
t possible to calculate the size of the critical structure structural defec
t and the mechanical properties of filled polymers, which are in agreement
with the experimental data.