Effects of gamma radiation on the impact strength of polypropylene (PP)/high density polyethylene (HDPE) blends

Polypropylene (PP) blends with the other polymer, like polyethylene (PE), is normally used as for improving PP impact strength. In this paper, we wanted to improve the PP/high density polyethylene (HDPE) impact strength by increasing the compatibility of PP/HDPE with gamma irradiation process that the un-irradiated ones were also used for comparison. It was obvious that the impact strength increased when the HDPE (10 phr) was added into the PP matrix, compared with neat PP. Meanwhile, the irradiated ones had higher impact strength than that of un-irradiated PP/HDPE blends. This was contributed to the finer compatibility in γ-irradiated PP/HDPE blends, seen from the SEM. Furthermore, the FTIR data also confirmed that the 1,4-butanediol diacrylate (BDDA) was grafted on the backbone of PP/HDPE blends by γ radiation. It speculated that this correlated with the compatibilization improvement in γ-irradiated PP/HDPE blends. Finally, the possible mechanism after γ-irradiation was also proposed in this paper. Keywords: PP, HDPE, Gamma irradiation, Impact strength