FTIR Spectroscopy characterization of PVC films grafted and heparinized by gamma radiation

Polymeric biomaterials with surface hemo compatibility properties had been successfully synthesized by the grafting of hydrophilic monomers onto commercial polymeric films by the simultaneous gamma irradiation process. In this work was studied the simultaneous gamma irradiation of flexible PVC films in systems containing the hydrophilic monomer DMAEMA in different concentrations (30% and 45%) and heparin sodium salt aqueous solution (0,25% w/v). The irradiation of the samples was carried out in a 60Co source, with doses of 0-16 kGy and dose rates of 0,5 to 0,8 kGy h-1. The grafted copolymers obtained by this method were characterized by FTIR-ATR and PAS spectroscopy in both DMAEMA studied concentrations. The graft copolymer characterization, accomplished by FTIR-PAS evidenced the largest grafting levels for the irradiated samples with 45% of DMAEMA, however heparin presence was only evident on irradiated samples with 30% of DMAEMA. This studies shows that the grafting of the monomer occurs in the surface of the films and the excess of the grafting difficult the heparin linkages in the polymeric matrix. (author)