Study on side-chain second-order nonlinear optical polyimides based on novel chromophore-containing diamines. I. Synthesis and characterization

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

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 156 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19991201)37:23<4330::aid-pola9>3.0.co;2-6

✦ Synopsis

Side-chain second-order nonlinear optical polyimides were prepared from four novel chromophore-containing diamines and 4,4Ј-(hexafluoroisopropylidene) diphthalic anhydride by a traditional two-step process that included a solution polycondensation followed by a chemical imidization. The four diamines were 2,4-di-␤-aminoethylamino-6-p-nitrophenylamino-1,3,5-triazine (M1), 4-nitro-4Ј-[N-(4,6-di-␤-aminoethylamino)-1,3,5-triazin-2-yl]amino azobenzene (M2), 2,4-di-paminophenylamino-6-p-nitrophenylamino-1,3,5-triazine (M3), and 4-nitro-4Ј-[N-(4,6di-4-aminophenylamino)-1,3,5-triazin-2-yl]amino azobenzene (M4). All the polyimides exhibited maximum ultraviolet-visible absorption peaks or shoulders of chromophores at wavelengths below 400 nm, and those based on M1 and M3 were transparent at wavelengths above 450 nm, whereas those based on M2 and M4 were transparent at wavelengths above 550 nm. The polyimides possessed high glasstransition temperatures (T g 's; 218 -247 °C) and thermal decomposition temperatures. They were soluble in aprotic solvents such as N-methyl-2-pyrrolidone, N,Ndimethyl acetamide, N,N-dimethyl formamide, and dimethylsulfone. Some were even soluble in common low-boiling-point solvents such as tetrahydrofuran.