The largest changes are observed in the direct values of the storage modulus, indicating differences in the mechanical properties of the materials. Table shows the values of the E' parameter of the materials recorded at the temperature before the glass transition (T = -60 ºC), at room temperature -after the glass transition (T = 25 ºC) and at the temperature before the melting point of the material (T = 80 ºC). The trend is very similar at all the points shown. The E' modulus values are clearly increased in proportion to the filler content in the composite. Moreover, this reinforcement is clearly dependent on the type of filler. The µHAp particles allow a much higher reinforcement of the material than the nHAp particles. For example, the storage modulus determined for the coPBS_20%µHAp composite at room temperature is 90% higher than for coPBS, while for coPBS_20%nHAp it is only 64 % higher.