EFFECT OF IONIZING-RADIATION ON THE CHARACTERISTICS OF EPDM UHMW-PE COMPOSITES/

Ultra high molecular weight polyethylene (UHMW-PE) fibers were used in a chopped form and at different concentrations as a reinforcing mater ial in ethylene-propylene-diene terpolymers (EPDM). The effect of radi ation dose and fiber concentration on the mechanical properties of the vulcanized rubber composites obtained was measured. It was found that gamma-irradiation improves the interfacial adhesion between UHMW-PE f iber (Spectra 1000) and EPDM matrix which wits detected by scanning el ectron microscopy (SEM). In addition, the Young modulus of the composi tes increases as the irradiation dose increases. Increasing the concen tration of the fibers up to 40 phr leads to an enhancement in mechanic al properties and swelling resistance of obtained composites, especial ly in the absence of carbon black. The absolute value of the modulus i ncreased by a factor of at least two with the addition of carbon black . Moreover the tear strength of reinforced and filled EPDM Was improve d with respect to reinforced rubber. (C) 1997 by John Wiley & Sons, Lt d.