Mechanical relaxation behavior of polyurethanes reinforced with the in   situ-generated sodium silica-polyphosphate nanophase
  Further exploration of hybrid organic/inorganic composites (polyurethane based with inorganic material sodium silica polyphosphate) properties with mechanical relaxometer gives ability to analyze microstructure of such materials in terms of chain reptation tubes filler's fractal aggregates and stress amplification. 
V.O. Dupanov, S.M. Ponomarenko
cond-mat.soft