A kinetic model for crosslinking free radical polymerization of DAIM (monomer diallyl isophthalate) with initiator CHPC (dicyclohexyl peroxydicarbonate) is developed. An improved version of Batch and Macosko＇s model was used to describe the initiator efficiency (f) and the active radical fraction (F-act). The experimental data of allyl and carbonyl group consumption are used for the optimization of the model and calculating off and F-act. From the developed kinetic model and experimental results, obtained by FT-IR measurements of monomer conversion, the introduction of the F-act was proved. Application of this model may be of use in process modeling of DAIM and other crosslinking polymerizations with CHPC as initiator.