Investigation of structural, morphological and dynamic mechanical properties of unvulcanized PDMS/silica compound

In this study, the interaction between the silica filler and polydimethylsiloxanes (PDMS) was investigated from the aspects of the bound rubber and morphological characterization. With special attention to the dynamic properties, the dynamic test was conducted by dynamic shear rheometer. The results show that the modified fillers disperse uniformly within PDMS matrix without aggregation and connect closely with the matrix than that of the unmodified fillers. Surface modification of filler increases the bound rubber content. The increase in silica loading leads to an increase in the silica-silica interaction and a decrease in filler-rubber interaction, which results in the aggregation of fillers and the increase of the bound rubber content. It was apparent that storage modulus, loss modulus and tanδ of unvulcanized PDMS/filler compounds filled with treated silica filler were lower than that of the untreated silica system. Moreover, the tanδ decreases with increasing silica loading.