A polycyanurate composition (I), wherein "n" is a positive integer of about 1 to about 10, and wherein R, R', and R'' comprising at least one of C, H, N, O, F, Si, P, S, Cl, Br, I, and any combination thereof. A method of making a polycyanurate composition (I) including, providing at least one semi-aliphatic polycarbonate (V), wherein R comprises at least one of C, H, N, O, F, Si, P, S, Cl, Br, I, providing at least one uncured reactive thermoset monomer, dissolving the polycarbonate in a solvent with a high vapor pressure or suspending the polycarbonate directly into the reactive monomer, mixing the liquefied polycarbonate with the uncured reactive thermoset monomer into a homogeneous liquid component, curing the liquid component into a viscous component, and exposing the cured component to temperatures of about 50.degree. C. to about 400.degree. C. forming tricyanurate linkages in the polycyanurate composition (I).