Effect of irradiation on the mechanical properties of high-density polyethylene reinforced with metallic fibres

In recent years, substantial efforts have been undertaken to investigate polymeric composites, which could represent a good alternative for obtaining other kinds of materials with desirable properties. Usually, the preparation of polymeric composites involves chemical treatment of the fillers to improve interaction between them and the polymer. In many cases, however, incompatibilities arise between the host matrix and the filling materials, such as organic, glass and metallic fibres. A possible way to overcome this difficulty is irradiation of the material involved so as to improve the curing of adhesives and resins. In this work, the effects of irradiation on the mechanical properties of high-density polyethylene (HDPE) reinforced with metallic fibres are presented. The samples were irradiated with a Co-60 source at doses between 10 and 70 kJ kg(-1) (kGy) using an irradiation rate of 4.8 kJ kg(-1) h(-1) in an oxygen atmosphere at room temperature. Afterwards, the tensile and impact properties were studied and compared with the values for pure HDPE. The results show that, at lower irradiation doses, the properties of the material are positively affected, reaching highest values at a proximately 10 kJ kg(-1). For the pure HDPE, Young's modulus increases up to 100% independently of the irradiation dose, while for the polymer containing metallic fibres this parameter increases to approximately 200%. Furthermore, the resistance to impact increases by up to 600% due to the presence of the metallic fibres. (C) 2002 Elsevier Science B.V. All rights reserved.