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:
The structure of the aromatic copolyester of poly(ethylene terephthalate) and 80 mol % of p-acetoxybenzoic acid was investigated by optical and electron microscopy, wide angle X-ray, and thermal analysis. The results of optical (LM) and electron microscopy (TEM and STEM) suggest the existence of ordered domains which appear as large lamellar thickness (∼200 Å) as has been described earlier for single crystals of the pure hompolymer of p-hydroxybenzoic acid (PHBA). However, the characteristic reversible endotherm at 330-360°C for PHBA could not be obtained. In isolated cases, the lamellar blocks retained their general dimensions up to 535°C whereas the surrounding matrix had degraded severely. An irreversible endotherm was observed at 303°C which suggested the presence of a higher degree of order than expected for a random copolymer. The irreversible nature of the endotherm is consistent with a transition from a semicrystalline structure to a liquid crystalline state. X-ray analysis with as received samples and thermally treated specimen provided additional support for more ordered regions.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1982.070270613
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