ALL plastics have a finite life span ,as the materials NEVER cease curing . Newer advanced polymers will endure decades provided there's NO defect in the forming process or material . What kills plastics is excessive heat and Sunlight ( Ultraviolet ) degrades near anything given along enough exposure .
MY basis for comment ,comes from direct involvement within the Composites Industry ,as in Aerospace Material Engineer for over #3 decades .
Pryor to that complete chemical analysis ,while obtaining My PhD. in Organic chemistry , Polymer disciplines . Along with a Masters in Structural Engineering . So you know I'm Not talking out the backside .