||The topic concerns with rheological properties of particle filled polymers with a special attention to their elasticity in the molten state. Although the effects induced by the presence of filler particles on melt elasticity are reported in literature, understanding of their origins and mechanisms is still lacking. Systematic study of the influence of particle size, concentration and surface modification on melts elasticity in linear and non-linear viscoelastic range will be performed. The filled systems will be studied experimentally by different rheological techniques (oscillatory shear, capillary rheometry). Structure of the composites will be visualized by electron microscopy. The applicant should have a basic background in polymer physics and polymer processing.