ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Internal cracking and microvoids are shown to form during room temperature storage of polycarbonate samples that have previously been exposed to boiling water. These microcracks or microvoids are actually disc-shaped pockets filled with water. This formation occurs due to the creation of water super-saturation conditions by cooling water-saturated specimens from 100°C to room temperature. As a result, water phase-separation, clustering, and microvoiding result and lead to deterioration of the mechanical properties. Visual healing of the microcracks is also sometimes observed at room temperature, especially under a dry atmosphere. Water from the water-filled pockets diffuses through the polycarbonate matrix to the external dry environment; the very thin emptied pockets then close and visually heal. This paper provides experimental data for the microvoiding process and clarifies the special mechanism of cracking/healing in polycarbonate samples.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760240308
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