DEGRADATION METHODS AND DEGRADATION KINETICS OF POLYMER-FILMS

Two accelerated degradation systems are described for the marine and soil exposures of polymer films. The systems were designed to provide controlled environments in which rates of degradation could be accelerated. The goal in developing these systems was to provide a standardized basis for comparing degradation kinetics of the films. Polymer film degradation kinetics are illustrated with two bacterial polyester copolymers (8% valerate and 24% valerate in butyrate-co-valerate polyester polymers) and cellophane. Initial data on weight loss per surface area, changes in molecular weight, and changes in mechanical properties of the films are described. The long-term goals are to correlate this type of data to environmental exposure conditions and to polymer morphology and chemistry.