| Popis: |
Service-life prediction for polymers remains an elusive goal. In this chapter, we describe efforts toward it for two polymers, polyethylene (PE) and a sealant. For both polymers, samples were weathered under accelerated laboratory conditions to characterize degradation as a function of ultraviolet radiation dose in MJ m−2. Samples were also weathered outdoors in Homestead Florida (FL), United States. Our intent was to predict the outdoor degradation using only the laboratory measurements. A Bayesian hierarchical model was used as a generative model for the laboratory measurements of degradation. It enabled predictions of outdoor degradation and the propagation of uncertainties associated with those predictions. The results of the exercises were mixed. The predictions were accurate for PE, including predictions of the high variability in the outdoor degradation measurements. The predictions were not accurate for the sealant. Potential reasons for this are discussed, and changes to our approach that improve the agreement between the outdoor predictions and the measurements of degradation are contemplated. |
