The homopolymer of unsaturated liquid crystal (LC) monomer for p-phenylene di 14-[2-(allyloxy) ethoxy] benzoate (p-PAEB), and copolymer poly (p-PAEB/St) of p-PAEB with styrene (St) have been synthesized. The LC behavior and thermal properties of p-PAEB and poly(p-PAEB/St) have been studied by Polarizing Optical Microscopic (POM), Differential Scanning Calorimetry, X-Ray Diffractometer (XRD), and Torsional Braid Analysis (TBA). The results demonstrate that LC phase texture and phase transition temperature of copolymers are affected by the composition of LC units in copolymers. The POM and XRD reveal that p-PAEB has a smectic phase structure; the copolymer of p-PAEB with styrene reveal deformed focal conics texture of smectic phase. The phase transition temperature range of p-PAEB is 120.5-191.5 degrees C, but the homopolymer of p-PAEB has a broad LC temperature range from 77 to 170 degrees C. The LC temperature range of poly(p-PAEB/St) is broadened with increased content of p-PAEB. The dynamic mechanical properties of LC polymer networks were investigated with TBA. The results indicate that the peak temperature of maximal mechanical loss is 114 degrees C and is decreased with the addition of styrene (c) 2006 Wiley Periodicals, Inc.