The first 8 composite samples were synthesized according to the amounts indicated in Table 1 in order to determine the highest amount of nanosilica that can be uniformly dispersed into the two kinds of matrix prepared: C20 and AG20. There are two main parameters that distinguish these composites; one concerns the kind of matrix: CP1, CP2, CP11 and CP12 contain C20 while CP3, CP4, CP13 and CP14 contain AG20. The other parameter is the amount of NSi increased from 25 to 100 in steps of 25 wt % for every matrix set, giving place to 8 samples in total. In order to determine which one of these matrices can rightly disperse the nanoparticles up to 100 wt %, 4 more samples were synthesized according to Table 1, using only the silica nanoparticles of 12 nm, ASi, in 75 and 100 wt %, comparing the matrix of C20 in CP19 and CP20 and the matrix of AG20 in CP21 and CP22, in order to observe the influence of such silica nanoparticles on the macro and microstructure and properties of the final composites.