Abstract
Nanoparticles of the standard pyrogenic Aerosil 1380 (Degussa) pregrafted by γ-irradiation with styrene were melt-compounded with the general purpose isotactic polypropylene (PP) homopolymer by a single-screw extruder. Storage G’(ω) and loss G”(ω) shear moduli of the neat PP (PP-0) and of the nanocomposite with the filler volume content 4.68 % (PP-4.68) were treated to derive the relaxation times spectra h (τ) using the NLREG computer program based on Tikhonov's method of non-linear regularisation. Drastic changes in the pattern, and broadening of the h (τ) to longer relaxation times for the PP-4.68 were attributed to the onset of plastic yield of a spatial network of filler particles coated with polymer boundary layer, preceding the macroscopic melt flow.