Effect of Various Additives on Tensile Properties of Polyethylene Films Irradiated in Air, Water, N₂, and Vacuum

Abstract

Low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) films of different thickness (0.06 mm, 0.2 mm, and 0.35 mm) were irradiated in vacuum, water, nitrogen, and air atmospheres for various doses from 40 kGy to 200 kGy. Radiation cross-linking occurred at lower doses and chain scission dominated at higher doses. The extent of radiation cross-linking and, consequently, tensile strength (TS) were found to be dependent on the oxidation layer as well as the thickness of the polyethylene (PE) films. The oxidation layer of the PE film was related to the amount of oxygen present in the media of irradiation When different additives from hindered amine light stabilizer (HALS) and ultraviolet light absorber (UVA) were incorporated into these PE films, the extent of radiation cross-linking as well as TS improved. Irradiation in water medium was found to improve radiation cross-linking and TS compared to irradiation in nitrogen and air atmospheres. Irradiation in a vacuum system did not produce any virtual improvement over water system irradiation. Irradiation in water medium is cost-effective compared to that in vacuum and nitrogen atmosphere.

Keywords:

• LLDPE
• LDPE
• γ-Radiation
• Cross-linking
• Oxidation
• Mechanical properties

Acknowledgments

The authors highly appreciate the KACST authority for providing them all possible facilities to carry out this work in the laboratory of the Institute of Atomic Energy Research. The authors are also grateful to Saudi Arabian Basic Industries Corporation (SABIC) for funding this work.