Functionalization of Low-density Polyethylene with Maleic Anhydride in the Molten State

In this study, low density polyethylene (LDPE) was modified with maleic anhydride (AM) in the molten state by using different concentrations of dycumil peroxide (DCP) (0.25, 0.50, 0.75 and 1.0 %). The materials obtained were characterized by gel content, acid-base titrations, infrared spectroscopy (IR), differential scanning calorimetry (DSC), thermogravimetry (TGA), rheological analysis, mechanical properties, hardness and oxygen permeability. Rheometric analysis indicated that the optimum time to obtain the mixtures is ca.7.5 minutes. IR analyses showed that the AM was grafted into the LDPE backbone. The grafting degree increased with the content of DCP and the highest grafting degree (1.12 +/- 0.015 %), was exhibited by the sample obtained employing the highest amount of DCP. Thermal stability of the functionalized samples was slightly higher than LDPE. The crystallinity of the functionalized samples was different, when compared to LDPE. The rheological behavior presented by the samples was pseudoplastic. The mechanical properties, hardness and the oxygen permeability were dependent of the amount of DCP and AM grafted into LDPE.