Synthesis and properties of polyimides, polyamides and poly(amide-imide)s from ether diamine having the spirobichroman structure

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

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 190 KB
• Volume: 35
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199706)35:8<1487::aid-pola18>3.0.co;2-3

✦ Synopsis

A novel spirobichroman unit containing dietheramine, 6,6-bis(4-aminophenoxy)-4,4,4,4,7,7-hexamethyl-2,2 -spirobichroman ( 3), was prepared by the nucleophilic substitution of 6,6-dihydroxy-4,4,4 ,4,7,7-hexamethyl-2,2 -spirobichroman with p-chloronitrobenzene in the presence of K 2 CO 3 followed by hydrazine catalytic reduction of the intermediate dinitro compound. A series of polyimides were synthesized from diamine 3 and various aromatic dianhydrides by a conventional two-stage procedure through the formation of poly(amic-acid)s followed by thermal imidization. The intermediate poly(amic-acid)s had inherent viscosities of 1.00-2.78 dL/g. All the poly-(amic-acid)s could be thermally cyclodehydrated into flexible and tough polyimide films, and some polyimides were soluble in polar solvents such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), and N,N-dimethylformamide (DMF). These polyimides had glass transition temperatures (T g ) in the range of 236-256ЊC, and 10% weight loss occurred up to 450ЊC. Furthermore, a series of polyamides and poly(amide-imide)s with inherent viscosities of 0.71-2.29 dL/g were prepared by direct polycondensation of the diamine 3 with various aromatic dicarboxylic acids and imide ring-containing dicarboxylic acids by means of triphenyl phosphite and pyridine. All the polyamides and poly(amide-imide)s were readily soluble in polar solvents such as DMAc, and tough and flexible films could be cast from their DMAc solutions. These polymers had glass transition temperatures in the range of 137-228ЊC and 10% weight loss temperatures in the range of 419-443ЊC in air and 404-436ЊC in nitrogen, respectively.