Effects of electron radiation and compatibilizers on impact strength of composites of recycled polymers

Abstract

The aim of this article was to show the effects of an electron radiation dose and compatibilizer on the Charpy impact strength ( σ c) and tensile-impact strength ( σ t) of composites made of blends of the following recycled polymers: low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), and poly(ethylene terephthalate) (PET). The purpose of both applying the high-energy electron radiation with doses of up to 300 kGy and adding a compatibilizer to the blends was to enhance impact strength of the studied composites and, at the same time, to investigate the possibility of using this method in the processing of recycling plastic waste. Styrene–ethylene/butylene–styrene elastomer grafted with maleic anhydride (SEBS- g-MA) and trimethylol propane trimethacrylate (TMPTA) were used as the compatibilizers, added at 10 and 1 wt %, respectively. It was found that, under the influence of SEBS- g-MA, the values of σ c and σ t for the studied composites increased by over three and almost five times, respectively. On the other hand, the electron radiation and TMPTA had no noticeable effect on these quantities, which might be due to the protective properties of aromatic rings included in the macromolecules of PS and PET. The study also showed that the inclusion of SEBS- g-MA enabled achievement of satisfactory impact strength of composites made of recycled polyolefins, PS and PET, while it was not necessary to use the electron radiation and TMPTA.