Abstract
Chemical and mechanical changes in outdoors exposed nylon 6 films were examined. The films with ca. 50 % and 25 % crystallinities exhibited the same changes in the molecular weight, molecular weight distribution, and UV spectrum, suggesting that crystalline and amorphous regions of the outdoors exposed nylon 6 degrade in a similar way. This may be because the amorphous region of nylon 6 under the outdoor weathering is in a glassy state. On the other hand, the elongation at break of the high-crystallinity film decreased more rapidly than that of the low-crystallinity film, because the former would have less tie molecules. In the film thickness range between 50 and 150 p m, the changes in the molecular weight, UV spectrum, and tensile strength were independent of the film thickness, while the elongation at break for a thicker film tended to decrease more slowly.
