Modification of a Theoretical Model for the Prediction of the Thermal Expansion Behavior of Particulate Composites: Application to Poly(vinyl chloride)/Talc Composites

The coefficients of thermal expansion (CTE) of poly(vinyl chloride) (PVC)/talc composites were tested and the experimental data showed that the CTE of PVC/talc composites were closely related to the talc particle size and its distribution; for a given talc volume fraction, the smaller the talc particle size, and the lower the CTE of the PVC/talc composites. The theoretical equations proposed by Sideridis and Papanicolaou and by Lombardo, which were based on a single, spherical particle size, were found to predict well the CTE of PVC/talc composites, but with the obtained interphase thicknesses were too large to be believed. In order to overcome the shortcomings of these equations, being without variation of filler particle size and its distribution, a modified model was proposed. It was found that the modified model can predict well the CTE of PVC/talc composites, with almost the same and more reliable interphase thicknesses for different talc particle sizes, confirming the correctness of the modified model to some extent.