Uncured and cured propoxylated glyceroltriacrylate (GPTA)/4-cyano-4＇-n-octyl-biphenyl (8CB) mixtures were prepared. The cured samples have been obtained by polymerization/cross-linking reactions using electron-beam irradiation. All cured samples with different compositions were exposed to the electron beam under similar conditions keeping the same dose and dose rate. The phase behavior of cured and the corresponding uncured GPTA/8CB mixtures was established by combining polarized optical microscopy and differential scanning calorimetry. The coexistence curve describing transitions from ordered to isotropic phase is analyzed using a theoretical framework in which the smectic-A and nematic order is described by a generalization of the Maier-Saupe theory developed by McMillan.