Synthesis and properties of aromatic polyamides derived from 2,6-bis(4-aminophenoxy)naphthalene and various aromatic dicarboxylic acids

✍ Scribed by Chin-Ping Yang; Sheng-Huei Hsiao; Chun-Cheng Yang

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 181 KB
• Volume: 35
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199708)35:11<2147::aid-pola5>3.0.co;2-v

✦ Synopsis

2,6-Bis(4-aminophenoxy)naphthalene (2,6-BAPON) was synthesized in two steps from the condensation of 2,6-dihydroxynaphthalene with p-chloronitrobenzene in the presence of potassium carbonate, giving 2,6-bis(4-nitrophenoxy)naphthalene, followed by hydrazine hydrate/Pd-C reduction. A series of new polyamides were synthesized by the direct polycondensation of 2,6-BAPON with various aromatic dicarboxylic acids in the N-methyl-2-pyrrolidone (NMP) solution containing dissolved metal salts such as CaCl 2 or LiCl using triphenyl phosphite and pyridine as condensing agents. The polymers were obtained in quantitative yields with inherent viscosities of 0.62-2.50 dL/g. Most of the polymers were soluble in aprotic dipolar solvents such as N,N-dimethylacetamide (DMAc) and NMP, and they could be solution cast into transparent, flexible, and tough films. The casting films had yield strengths of 84-105 MPa, tensile strengths of 68-95 MPa, elongations at break of 8-36%, and tensile moduli of 1.4-2.1 GPa. The glass transition temperatures of the polyamides were in the range 155-225ЊC, and their 10% weight loss temperatures were above 505ЊC in nitrogen and above 474ЊC in air.