Phase transitions in mesophase macromolecules. III. The transitions in poly(ethylene terephthalate-co-p-oxybenzoate)

✍ Scribed by Meesiri, Wiriya ;Menczel, Jozsef ;Gaur, U. ;Wunderlich, Bernhard

• Book ID: 105334135
• Publisher: Wiley (John Wiley & Sons)
• Year: 1982
• Tongue: English
• Weight: 641 KB
• Volume: 20
• Category: Article
• ISSN: 0098-1273
• DOI: 10.1002/pol.1982.180200413

✦ Synopsis

Abstract

The glass and melting transitions of poly(ethylene terephthalate‐co‐p‐oxybenzoate)s have been studied by differential scanning calorimetry. Despite the higher glass transition expected for polyoxybenzoate, there is almost no change in the glass transition temperature up to 63 mol % oxybenzoate (353 ± 4 K). At high oxybenzoate concentration there seems to be a discontinuous jump to a glass transition of 450 K. This high glass transition has been observed in two‐phase materials down to 30 mol % oxybenzoate. The melting transition shows signs of isodimorphism with a minimum in melting temperature at about 60–70 mol % oxybenzoate, 60 K below the melting temperature of poly(ethylene terephthalate). The thermal properties are little affected by the change of the noncrystalline parts of the molecules to a mesophase structure. The transition to the isotropic phase could not be analyzed because of prior decomposition.