Polypropylene fumarate (PPF) as unsaturated linear polyester crosslinked with three different monomers namely N-vinyl pyrroliclone (NVP), methyl methacrylate (MMA), and a mixture of NVP/MMA (1 : 1 weight ratio) were prepared. The chemical structure of the PPF was characterized by means of H-1-NMR, FTIR, as well as GPC. The mixture of PPF resin with the crosslinking monomers filled with (60, 65, and 70 wt %) of gypsum were also prepared as bone cement composites. The dielectric measurements carried out on these prepared samples at frequency range from 100 Hz-100 kHz indicate that the permittivity epsilon' and dielectric loss epsilon '' follow the order NVP > NVP/MMA > MMA. Both parameters were found to decrease by increasing the percentage of gypsum. According to Frohlich and Havriliak Nagami functions, the relaxation times obtained could be attributed, respectively, to Maxwell-Wagner effect and to the relaxation process related to carboxyl, hydroxyl, and ester functions associated with main chain. The latter relaxation time was found to increase by increasing gypsum content, whereas the electrical conductivity was found to decrease. The mechanical data of the investigated samples containing 60 wt % gypsum is characterized by the best properties and the behavior of the composites follows the order found in the case of dielectric properties (NVP > NVP/MMA > MMA). Formation of carbonate apatite of composite samples loaded with 60 wt % gypsum after immersing the samples for 4 weeks in simulated body fluid (SBF) was confirmed by the dielectric measurements and FTIR spectroscopy. In addition, the weight loss and the mechanical properties for such systems were also studied. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 116: 876-885, 2010