Poly(p-phenylenebenzobisimidazole), PBI, is a rigid-rod polymer with a fully conjugated backbone having superior mechanical properties, thermo-oxi- dative and solvent stabilities. The stabilities cause processing difficulties and in terms limit its applications in critical technologies, such as conducting polymers, nonlinear optics, and solid polyelectrolytes.
In this study, a chemical derivative of PBI, poly[1,7-dihydrobenzo[1,2- d:4,5-d¡¦]diimidazo-2,6-diyl[2-(2-sulfo)-p-phenylene]], sPBI, was synthesized by polycondensation reaction of 1,2,4,5-tetraaminobenzene tetrahydrochloride with 2-sulfoterephthalic acid in poly(phosphoric acid). Isolated sPBI was measured in 30oC methanesulfonic acid for an intrinsic viscosity as high as 10.5 dL/g. sPBI polymer was then reacted with 1,3-propanesultone in dimethylsulfoxide containing sodium hydride for water-soluble rigid-rod polyelectrolyte, poly[1,7- dipropylsulfobenzo-[1,2-d:4,5-d¡¦]diimidazo-2,6-diyl-[2,(2-sulfo)-p-phenylene]], sPBI-PS(Na+). sPBI-PS(Na+) was further converted to sPBI-PS(Li+) with hydrochloride and followed with lithium hydroxide. Various analyses were applied to ascertain chemical structure, purities and thermal properties of synthesized monomers and polymers. sPBI-PS(Li+) aqueous solutions were doped individually with lithium salts of LiI, LiBF4, and LiCF3SO3 at concentrations up to 1.7¡Ñ10-5 wt./wt., which were cast into freestanding films of 10-25 £gm in thickness. Direct-current conductivity measured at room- temperature parallel to the film surface was as large as 9.74¡Ñ10-5 S/cm. The ionic nature of the conductivity was revealed by constant-voltage depletion measurements. X-ray scattering results suggested that the cast film was in-plane isotropic but out-of-the plane anisotropic with the rigid-rod backbone lying in the plane of the film.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0215101-141735 |
| Date | 15 February 2001 |
| Creators | Chen, Yun-Sheng |
| Contributors | Shih Jung Bai, An-Chung Su, Jin-Long Hong |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0215101-141735 |
| Rights | not_available, Copyright information available at source archive |
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