THE EFFECT OF RADIATION ON POLYETHYLENE,

Starting with a standard grade polyethylene or perhaps one of even lower molecular weight, it is possible by a judicious selection of irradiation dose to effect a marked increase in tensile strength without any significant loss in elongation to convert a material of poor crack-resistance to one which has complete crack-resistance to markedly improve the heat distortion of the polymer and to improve its weathering characteristics. All these beneficial improvements can be brought about without any significant loss in the excellent dielectric properties of polyethylene. It also appears that the addition of various essential ingredients i.e., carbon black and antioxidant did not affect the irradiation efficiency nor presumably were the additives adversely affected. Further study is, however, necessary to elucidate the effect of different additives under varying conditions. This study indicates that at a dose of somewhere in the range of 8 to 16 million reps optimum properties can be obtained.