PP was supplied by Atofina (PPH 7060) with a melt flow index MFI=12 g/10 min. The molecular weights
are: Mn= 67,300g.mol–1 and Mw= 273,000 g.mol–1. The PS (LACQRENE Cristal PS 1960N) with Mn=
49300 g.mol–1 and Mw= 93500 g.mol–1, and Two poly(ethylene-co-vinyl acetate) (EVA), of different molar
masses have been used (table1) are supplied by Arkema. The amount of acetate groups contained in these
copolymers is 28% by weight. The zero shear viscosities of these EVA are reported in table 1 at T=200°C.
Figure 1, 2 shows respectively the variations of the complex shear modulus (G*(w)=G¢(w)+jG²(w)) of PP,
PS at the temperature T=200°C, and the variations of the absolute complex viscosity of EVA03, and
EVA420 at the temperature T=200°C. . The silica content was 3 wt% of the total material. Two types of
nanosilica (SiO2) were used. A hydrophilic pyrogenic silica, HDK® N20, with a specific surface area of 170 -
230 m2/g and a hydrophobic nanosilica, HDK® H20 RC, having the same specific surface area treated with
trimethoxyoctysilane. The two types of silica are aggregates of primary spherical particles having an average
diameter of 12 nm. Both of them were kindly supplied by Wacker Corp.