Pre-polymers prepared by modifying divinyl benzene by introducing dimethyl siloxane units of different chain lengths were polymerised with divinyl benzene using free radical initiators. The dynamic mechanical properties of the resulting networks were studied. The DMA curves were interpreted based on the reaction mechanism obtained using FT-NIR and ESR spectra. The peak widths of the loss modulus and tan delta curves were interpreted considering the crosslinking reactions in the pre-polymer/divinyl benzene mixtures and micro gelation resulting from the crosslinking.