Massive internal fracture of an amorphous polyester.
When amorphious polyethylene terephthalate is subjected to a tensile load of 2 to 4 x 10(8) dynes per square centimeter wthin the approximate temperature range 40 degrees to 70 degrees C, an unusual optical effect occurs. The transparent polymer film is suddenly transformed into a brilliantly reflecting strip with the luster of silver. Extensive formation of voids accounts for the unorthodox behavior.
Yannas
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