PHYSICAL MODELING OF THE INTERPHASE IN AMORPHOUS THERMOPLASTIC GLASS BEAD COMPOSITES

Mechanical spectrometry was performed on polystyrene/glass bead and poly(styrene-co-methacrylic acid)/glass bead composites to test for the influence of the interphase on molecular mobility. To quantify these motion changes, a physical model was developed to predict the deformation of amorphous materials near T-g. Before applying this model, the dynamic mechanical behavior of the two phases (matrix and inclusions) must be separated to remove the reinforcement effect of the fillers and to keep only the physical crosslinking effect of the amorphous phase by the inclusions. It was shown that (i) the fillers can induce the formation of specific interactions, which act as physical ties, reducing molecular mobility and that (ii) the decrease in molecular motion with increasing filler content is enhanced for fillers coated by a silane coupling agent.