Syntheses and properties of polyamides from ether diacid having the spirobichroman unit

✍ Scribed by Sheng-Huei Hsiao; Ching-Yen Yang

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 175 KB
• Volume: 35
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199706)35:8<1479::aid-pola17>3.0.co;2-4

✦ Synopsis

A novel hexamethylspirobichroman (HMSBC) unit-containing dicarboxylic acid, 6,6 -bis(4-carboxyphenoxy)-4,4,4 ,4,7,7-hexamethyl-2,2 -spirobichroman ( 3), was derived from nucleophilic substitution of p-fluorobenzonitrile with the phenolate ion of 6,6-dihydroxy-4,4,4 ,4,7,7-hexamethyl-2,2 -spirobichroman (1), followed by alkaline hydrolysis of the intermediate bis(ether nitrile). Using TPP and pyridine as condensing agents, a series of polyamides with inherent viscosities in the range of 0.82-1.14 dL/g were prepared by the direct polycondensation of dicarboxylic acid 3 with various aromatic diamines. All the obtained polymers were noncrystalline and soluble in various organic solvents such as N,N-dimethylacetamide (DMAc) and Nmethyl-2-pyrrolidone (NMP). Except for the polymer derived from benzidine, the other polyamides could be solution cast into transparent and tough films, and their tensile strengths, elongations at break, and tensile moduli were in the range of 56-76 MPa, 4-59%, and 1.6-2.0 GPa, respectively. These polyamides had glass transition temperatures in the range of 183-200ЊC with 10% weight loss above 420ЊC.