Preparation and properties of thermally stable copolyimides based on novel second-order nonlinear–optical chromophore containing diamines

✍ Scribed by Yu Sui; Xiao-Xia Guo; Jie Yin; Yan-Gang Liu; Jian Gao; Zi-Kang Zhu; De-Yin Huang; Zong-Guang Wang

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 159 KB
• Volume: 76
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(20000613)76:11<1619::aid-app2>3.0.co;2-s

✦ Synopsis

Thermally stable copolyimides were prepared from two novel second-order nonlinear optical chromophores containing diamines, 4-nitro-4Ј-[N-(4,6-di-␤-aminoethylamino)-1,3,5-triazin-2-yl]aminoazobenzene (M1) and 4-nitro-4Ј-[N-(4,6-di-4-aminophenylamino)-1,3,5-triazin-2-yl]aminoazobenzene (M2); two codiamines, 4,4Ј-diamino-3,3Јdimethyl diphenylmethane (MMDA) and bis-(3-aminopropyl)-1,1Ј,3,3Ј-tetramethyldisiloxane (SiDA); and 3,3Ј,4,4Ј-diphenyl ether tetracarboxylic acid dianhydride (OPDA). All copolyimides possess high glass transition temperatures (T g 's) between 237 and 271°C. Copolyimides based on M2 do not exhibit an obvious change in T g as the M2 content is increased, while those based on M1 show a slight decrease in T g as the M1 content is increased. All copolyimides exhibit high thermal decomposition temperatures. The copolyimides are soluble in aprotic solvents such as NMP, DMAc, DMF, DMSO, and 1,4-butyrolactone. Some are even soluble in common low boiling point solvents such as THF and chloroform. The refractive index of a copolyimide is increased as the chromophore content is increased, while the birefringence of a copolyimide does not exhibit strong dependence on the chromophore content.