| The objective of this research was to incorporate chemically and thermally-stable, nonlinear optical (NLO) chromophores containing oxazoles into polyimide backbones. The approach involved the synthesis and polymerization of diamines containing the chromophores. Thus, 4,5-bis(4-aminophenyl)-2-(4{dollar}spprime{dollar}-nitrophenyl)oxazole, 4,5-bis(4,4{dollar}spprime{dollar}-bis(4-aminophenoxy)phenyl) -2-(4{dollar}spprime{dollar}-nitrophenyl) oxazole and 4,5-bis(4-aminophenyl)-2-(4{dollar}spprime{dollar}-dimethylaminophenyl) oxazole were synthesized and polymerized with 3,3{dollar}spprime{dollar},4,4{dollar}spprime{dollar}-biphenyltetracarboxylic dianhydride (BPDA), 2,2{dollar}spprime{dollar}-hexafluoroisopropylidine bis(phthalic anhydride) (6FDA) and 2,2{dollar}spprime{dollar}-bis{dollar}{lcub}{dollar}4-((3,4-dicarboxylic anhydride)phenoxy) phenyl{dollar}{rcub}{dollar}propane (BisADA) in refluxing m-cresol or p-chlorophenol containing catalytic amounts of isoquinoline. Several of the polyimides obtained were soluble in chloroform and 1-methyl-2-pyrrolidinone (NMP). The polymers had intrinsic viscosities of 0.40 to 0.76 dL/g (0.5g/dL in NMP at 30{dollar}spcirc{dollar}C) and glass transition temperatures that ranged from 262{dollar}spcirc{dollar}C to 266{dollar}spcirc{dollar}C. The polyimides underwent 5% weight losses above 400{dollar}spcirc{dollar}C when subjected to thermogravimetric analysis in air and nitrogen. |
