Outdoor Performance of Plastics. VII. Haze and Gloss

摘要

This is the seventh in a series of reports on outdoor weathering of 20 plastics in 3 climates. After 3 years exposure, data show that climate is only slightly significant in the increase of haze and loss of gloss. Thickness of the plastic was found to be a significant variable in haze development. With the exception of polymethyl methacrylate, the high-gloss plastics were not outstanding in their retention of gloss. A simple qualitative scheme was developed to relate physical surface characteristics and gloss. This explains how roughness may cyclically increase and decrease, but gloss tends primarily to decrease. Haze measured with 420 nanometer light was approximately linearly proportional to, an usually somewhat greater than haze at 550 nm. These two wavelengths of light show almost identical patterns of haze development.