Calculation of the efficiency of ultraviolet screeners in plastics

摘要

AbstractCalculation of the effect of light absorbers (UV screeners) on the photochemistry of polymers shows that a critical factor in reducing the rate of photodegradation is the thickness of the actual degraded layer. When the degradation is confined to a zone within a few microns of the exposed surface, the efficiency of light absorption as a stabilization mechanism is greatly reduced. The relative absorptivity of the base resin and pigment loadings are calculated to have a minor effect on stabilization efficiency for polymers having thin layers of degradation.