An integrating sphere-based ultraviolet exposure chamber design for the photodegradation of polymeric materials

摘要

The primary method for obtaining laboratory weathering data for a wide range of commercial polymer products including coatings, textiles, elastomers, plastics and polymeric composites is through the use of ultraviolet radiation exposure chambers (UV- chambers). Although numerous improvements have been made in the design of UV-chambers over the last 80 years, the repeat- ability and reproducibility of the exposure results from these chambers have remained elusive. This lack of reproducibility and repeatability is attributed to systematic errors in their design, operation, and control which, in turn, has prevented comparisons of the performance of competing construction materials exposed in the same environment, comparisons of the performance of the same material exposed in different laboratories, and the comparison of field and laboratory results. The paper re-examines current UV-chamber designs, discusses possible sources of systematic error associated with these chambers, and describes an innovative UV-chamber design having a basis in integrating sphere technology which greatly reduces the magnitude of these errors.