INHIBITION OF RADIATION DEGRADATION BY HYDROGEN-DONATING HYDROAROMATICS

The inhibiting effect of a multicomponent hydroaromatic type additive (HHAP) produced from petroleum which showed prominent radical-scavengi ng ability with DPPH (2,2-diphenyl-1-picrylhydrazyl) was tested agains t the radiation degradation (gamma-ray in air at room temperature) of mineral oil in comparison with the effect of a hindered phenolic antio xidant, 2,6-di-tert-butyl-p-cresol (DBPC). The obvious effects of HHAP on the restriction of the increases of acid value and carbonyl absorb ance were preserved up to 2500 kGy. However, the structural changes th at occurred in DBPC were shown by analyses of the carbonyl absorbance and of the OH group absorbance by IR. DBPC itself was analyzed by gas chromatography as the irradiation dose accumulated. The differences in the inhibiting effects of a hindered phenolic antioxidant and HHAP be tween the thermal oxidation and radiation degradation of polyolefins a re discussed from these results. HHAP, which does not have a functiona l group containing heteroatoms, can be considered to be resistant to r adiation as well as to heat.