Dynamic Mechanical Analysis of Hybrid Fibre/Glass Microspheres Composites

This article presents the results obtained in a current study of the viscous properties on hybrid short fibre/hollow glass microspheres composites fabricated with epoxy binder. The effect of the filler volume fraction and of the fibre reinforcement on the dynamic stiffness modulus, damping coefficient and glass transition temperature was studied. These properties were determined using dynamic mechanical analysis (DMA) in three points bending mode. The specimens were cut from plates produced by vacuum resin transfer moulding with microspheres weight contents up to 17%. Net resin exhibits storage modulus significantly higher than the 2% in weight of microspheres foam, while negligible effect was observed on the maximum loss modulus, maximum damping coefficient and glass transition temperature. The increase in filler volume fraction tends to decrease significantly storage and loss modulus at stable regions and the maximum damping coefficient, while glass transition temperature is only marginally affected. The addition of low contents of short fibre increases significantly storage modulus, particularly for carbon fibre, while maximum loss modulus does not exhibit a well-defined tendency. Important reduction in the maximum damping coefficient was observed by the addition of both fibre reinforcements.