Laser light scattering studies of soluble high performance fluorine-containing polyimides, 1: Polyimide synthesized from 2,2′-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride and 2,2′-(trifluoromethyl)-4,4′-biphenyldiamine
Publication in refereed journal

香港中文大學研究人員
替代計量分析
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其它資訊
摘要Five fractions of a polyimide synthesized from 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 2,2′-(trifluoromethyl)-4,4′-biphenyldiamine (PFMB) (6FDA/PFMB) in tetrahydrofuran (THF) at 3O°C were investigated by a combination of static and dynamic laser light scattering (LLS). The relations of (nm) = 2.38 × 10-2 M̄w
0.560 and A2 (mol · cm-3 · g-2) = 2.1 × 10-1 M̄w
-0.43 were established, where M̄w, and A2 are weight-average molecular weight, average hydrodynamic radius and second virial coefficient, respectively. A combination of M̄w and the translational diffusion coefficient distribution G(D) leads to a relation of D(cm2/s) = 2.41 × 10-4 M-0.564· With this relation, we successfully convert each G(D) into a corresponding molecular weight distribution (MWD). On the basis of the Benoit-Doty theory, we found that the persistence length and the Flory characteristic ratio C∞ of the 6FDA-PFMB chain are ∼3.3 nm and ∼40, respectively, indicating that the 6FDA-PFMB chain is more extended than typical random-coil chains. On the other hand, the ratio of the radius of gyration to the hydrodynamic radius, i.e., / ∼ 1.8, together with the values of the exponents (∼0.56) indicate that the 6FDA-PFMB chain has a coil chain conformation. Therefore, the 6FDA-PFMB chain has an extended coil conformation in THF at 30°C.
著者Kwan S.C.M., Wu C., Li F., Savitski E.P., Harris F.W., Cheng S.Z.D.
期刊名稱Macromolecular Chemistry and Physics
出版年份1997
月份11
日期1
卷號198
期次11
出版社John Wiley & Sons Ltd.
出版地United Kingdom
頁次3605 - 3614
國際標準期刊號1022-1352
語言英式英語

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