Effect of Pigments on the Aging Characteristics of Polyolefins

Abstract

Pigments are used extensively in polymers for a variety of reasons such as appearance, opacification, protection and identification. In many cases^{1, 2} the pigment additive can affect the thermal oxidative stability o f a polymer and alter the long term aging characteristics of the material. The effect pigments have on polymers are often small and unimportant because the design lifetime of the product is short. However, the polyolefin resins used in telecommunication wire and cable are designed for long useful lifetimes, in many cases 40 years, and pigments can reduce these lifetimes. Field surveys of pigmented insulations and cable jackets show that white and red polyethylenes have twice the disintegration rate of other light colors, 3 while black polyethylenes rarely fail.^{3, 4}