The crosslinking of polyethylene by ultraviolet radiation
Crosslinking of low density polyethylene by ultraviolet light was carried out. The polyethylene was incorporated with high functionality monomer (crosslinking agent) and photoinitiator. Saturated and unsaturated hydrocarbon model systems were used in the project, in order that a better understanding of the crosslinking process could be established. A comparison between photoinitiation crossing and Gamma irradiation process of the model systems and polyethylene was also carried out. It was found that the properties of the photoinitiated crosslinked polyethylene were significantly improved, especially the flow properties and the environmental stress cracking resistance (ESCR). Other properties such as Tensile strength, Glass transition temperature (Tg) and melting temperature (Tm) were not greatly affected. The significant improvement in the flow properties was due to the formation of the microphase of the high functional crosslinking agent which was incorporated in the polyethy.lene matrix. The formation of such a microphase was only achieved within the amorphous region of the polyethylene.