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Structure and properties of poly-2,5-distyrylpyrazine

✍ Scribed by Kanetsuna, Hisaaki ;Hasegawa, Masaki ;Mitsuhashi, Shigenobu ;Kurita, Toshio ;Sasaki, Kanji ;Maeda, Katsuhiro ;Obata, Hiroko ;Hatakeyama, Tatsuko

Publisher
Wiley (John Wiley & Sons)
Year
1970
Tongue
English
Weight
688 KB
Volume
8
Category
Article
ISSN
0449-2978

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✦ Synopsis

Abstract

Poly‐2,5‐distyrylpyrazine (poly‐DSP) was investigated by differential thermal analysis (DTA), thermogravimetric analysis (TGA), and measurements of dynamic viscoelastic and electrical properties. From DTA and TGA studies it was confirmed that poly‐DSP melts at 321°C and depolymerizes rapidly to the monomer at temperatures between 335°C and 345°C in helium. The polymer is affected by oxygen above 200°C. The E′ value from dynamic viscoelasticity measurements on amorphous film is 2 × 10^11^ dyne/cm^2^ at room temperature. It decrease abruptly in the temperature range 140–150°C; but the net decrease of E′ within this temperature range is relatively small. The electrical properties of amorphous poly‐DSP are characterized by a small temperature dependence of the dielectric constant between room temperature and 100°C. The dielectric loss tangent was observed to be small, and the dc conductivity was extremely small. It is concluded that rotation of the phenyl branches in the polymer occurs above −30°C and the glass transition occurs at about 150°C. These properties are discussed in some detail in relation to the polymer structure.

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