New aromatic benzazole polymers. I. Benzobisthiazole and benzobisoxazole polymers with main-chain triarylamino units

✍ Scribed by Loon-Seng Tan; K. R. Srinivasan; Shih Jung Bai

• Book ID: 101270169
• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 250 KB
• Volume: 35
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19970730)35:10<1909::aid-pola5>3.0.co;2-i

✦ Synopsis

Thermally stable, nonrigid-rod poly(benzobisthiazoles), (R)TPA-PBZT , where R Å H, Me, NMe 2 , and OH, and poly(benzobisoxazoles), (R)TPA-PBO, where R Å Me, NMe 2 containing electron-rich triarylamine groups with various para-substituents (Rs) on the pendent phenyl ring, were synthesized from either 2,5-diamino-1,4benzenedithiol dihydrochloride or 2,4-diamino-1,5-benzenediol dihydrochloride and the respective triarylamine-based dinitrile or diacid monomer in polyphosphoric acid. Whereas (R)TPA-PBZT polymers were obtained in moderate molecular weights, analogous (R)TPA-PBO polymers were only prepared in low molecular weights. No lyotropic behaviors, characteristic of the unmodified rigid-rod benzazole polymers, as evidenced by the absence of either stir opalescence or birefringence under crosspolarizers, were observed for these homopolymers at about 10 wt % polymer concentration. Among these polymers, only (Me)TPA-PBZT and (NMe 2 )TPA-PBZT formed cast films with good mechanical integrity. In their pristine state, their film conductivity values were in the range of 10 010 -10 09 S/cm at room temperature. Upon exposure to iodine vapor, their conductivities were increased to the maximal values of 5.0 1 10 05 S/cm ((Me)TPA-PBZT ) and 4.1 1 10 04 S/cm ((NMe 2 )TPA-PBZT ).