ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
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:
Crystalline and amorphous sheets of poly(butylene terephthalate) (PBT) were drawn in the temperature range of 20-150°C. The molecular orientation and the relative amount of α- and β-form crystals in the stretched sheets were studied by wide-angle X-ray diffraction (WAXD) and density measurements. When crystalline PBT sheets are drawn at lower temperatures, α-form crystals are partially transformed into β-form crystals. Both α- and β-form crystals are formed by drawing amorphous PBT sheets. The relative amount of α- and β-form crystals is much more sensitive to drawing temperature than to draw ratio. The α-form crystallinity is higher at higher drawing temperature and increases slightly with increasing draw ratio. The second moments of orientation functions of α- and β-form crystals increase with increasing draw ratio, and the increase of the orientation function is suppressed at higher draw ratio. The orientation function of α-form crystals is higher than that of β-form crystals in a same sample.
Additional Material:
14 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1992.070450709
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