Accession Number : AD0656236

Title :   THE DEPENDENCE OF PHOTOLYTIC DEGRADATION OF POLYETHYLENE ON DEGREE OF DISPERSION OF CARBON BLACK,

Corporate Author : BELL TELEPHONE LABS INC MURRAY HILL N J

Personal Author(s) : Lanza,V. L. ; Heiss,J. H. ; Martin,W. M.

Report Date : 1958

Pagination or Media Count : 16

Abstract : The resistance to weathering of these polyethylene-carbon black formulations can be predicted from the Ambrose modification of the Angstrom approximation. The higher negative optical density-wavelength slopes indicate the more weather resistant compounds. The photo-induced degradation in black formulations is mainly a surface phenomenon which greatly affects the low temperature brittle properties. The dielectric loss, enhanced by the production of polar groups during degradation, depends upon bulk properties and does not reflect the changes in physical properties, especially during the early stages of degradation. Experimental data show, for unweathered compounds, a direct relationship between dielectric loss and the degree of dispersion of a single carbon black in polyethylene. When the carbon black particles approach ultimate dispersion, as evidenced by high negative values for optical slope, the dielectric loss tends toward a minimum value. (Author)

Descriptors :   (*POLYETHYLENE PLASTICS, DEGRADATION), (*PHOTOLYSIS, POLYETHYLENE PLASTICS), CARBON BLACK, ADDITIVES, SCATTERING, AGING(MATERIALS), BRITTLENESS, DIELECTRIC PROPERTIES

Subject Categories : Radiation and Nuclear Chemistry
      Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE