A study of roles of different valence of copper oxide interaction with electron beam irradiation in polyethylene composite

The aim of this research was to investigate the interaction of electron beam irradiation on the different valence of copper (I) and copper (II) oxides (Cu₂O and CuO) added low-density polyethylene (LDPE) composites. The results showed the increasing of Cu₂O loading level in replacing the CuO has significantly reduced the gel content (or degree of cross-linking networks) in LDPE matrix. This is due to the poorer effect of Cu₂O in inducing the polymeric free radicals. Meanwhile, the application of low irradiation dosage (≤100 kGy) has significantly increased the crystallite size for crystallite peak (110) of all LDPE composites. However, further increment in irradiation dosages from 100 to 300 kGy has gradually reduced the crystallite size of deflection peak (110). The tensile strength of all LDPE composites was gradually decreased with increasing of Cu₂O loading level due to agglomeration of Cu₂O and CuO particles in LDPE matrix. In addition, the increasing of irradiation dosages on all Cu₂O /CuO added LDPE composites has gradually increased the tensile strength by inducing the formation of the cross-linking networks in LDPE matrix. Nevertheless, the increasing of irradiation dosage has gradually decreased the elongation at break of all Cu₂O /CuO added LDPE composites. This is due to the higher degree of cross-linking networks in LDPE matrix could restrict the mobility of LDPE macromolecular chains when subjected to straining stress.