Synthesis and characterization of poly(benzazoles) containing the bicyclo[2.2.2]octane moiety

✍ Scribed by Delynn M. Hayes; Issifu I. Harruna

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 123 KB
• Volume: 36
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19980130)36:2<277::aid-pola10>3.0.co;2-l

✦ Synopsis

Poly(benzobisoxazoles) (PBOs), poly(benzobisthiazoles) (PBTs) and copolymers thereof containing the 2,5-dihydroxybicyclo[2.2.2]octane moiety have been prepared and studied. The homopolymers were synthesized by the polycondensation of 2,5dihydroxybicyclo[2.2.2]octane-1,4-dicarboxylic acid with 4,6-diamino-1,3-benzenediol dihydrochloride or 2,5-diamino-1,4-benzenedithiol dihydrochloride in poly(phosphoric acid). Random and block copolymers (PBO-PBT) were also prepared. The polymers were characterized by solubility, X-ray diffraction, spectroscopy (infrared and solidstate 13 C nuclear magnetic resonance), and thermal analysis such as differential scanning calorimetry and thermogravimetric analysis. Thermogravimetric analysis showed thermal stability of the polymers above 375ЊC in air and under argon atmosphere. The polymers exhibited high resistance to organic and inorganic solvents. The polymers were converted to the more stable aromatic polymers via dehydration and retro Diels-Alder reactions of the 2,5-dihydroxybicyclo[2.2.2]octyl moiety by pyrolysis.