Effect of reinforcing fillers and plasticizer on mechanical properties of cork-rubber composites

Composed of a rubber matrix filled with cork granulates, cork-rubber composites are an example of elastomeric materials used for vibration isolation. As a first step towards the development of a model that could help throughout the material development stage, a screening experiment was conducted to identify which formulation related variables affect the mechanical properties of a cork-rubber composite, including static stress and natural frequency when submitted to compressive loads. Using statistical methods, the influence of reinforcing fillers and plasticizer on the composite properties was examined. The results of fillers analysis were within the expected as the application of a harder filler provided higher stiffness samples. Higher values of mechanical properties related to compression behaviour were observed for high level quantities of filler and filler activator. In the reinforcing filler study, interactions between parameters were also detected in some cases. Different results were also found by changing only the plasticizer type.