CARBOXYLATION OF LINEAR LOW-DENSITY POLYETHYLENE THROUGH GAMMA-IRRADIATION IN PRESENCE OF SUPERCRITICAL CARBON-DIOXIDE - GRAFTED GROUPS ANALYSIS VIA DERIVATIZATION PROCEDURES

A linear low-density polyethylene was gamma irradiated in presence of carbon dioxide under supercritical conditions. As already reported, th is process can be an interesting way to graft carboxylated functions t o the polyethylene chains. In this work a detailed analytical investig ation of the carboxylation products grafted on LLDPE are presented. De rivatization procedures with sulfur tetrafluoride and nitrogen monoxid e, in order to selectively convert the carboxylated functions into gro ups more easily identified and quantified by FTIR, were performed. The chemical nature of the grafted groups is very similar to that obtaine d through gamma irradiation in air; furthermore, a significant degree of crosslinking is observed.