Based on a series of study to improve the electrooptic coefficient (r33) of nonlinear optical polyimides (NLO-PI) containing benzobisthiazole- based chromophores in our lab, this work concentrated on the modification of the benzobisthiazole-based chromophore VIII (r33 = 6.62 pm/V). At first, a hydroxyl-containing polyimide was first synthesized by using dianhydride and diamine as reactants via thermal imidization and the benzobisthiazole-based chromophores were synthesized by using DABDT as the starting monomer. The NLO precursors were obtained by the Mitsunobu reaction via ether linkage between PI and chromophore; it was then cured at 300¢J to result in the final NLO-PI. The benzobisthiazole-based chromophore of VIII was modified with an insertion of the ethoxy group between the NLO moiety and the main PI backbone to get the NLO-V-1. This method makes the chromophore easier to orient under the electric field during poling; thus a higher r33 (7.4 pm/V) is ensured. NLO-V-2 is another modified sample which had a phenyldiazene group inserted into the chromophore of VIII to increase the conjugated length; this results in a red shifts from 390 nm (VIII) to 484 nm in UV-abs spectrum but the r33 (5.8 pm/V) has only a slight improvement.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0724107-171236 |
| Date | 24 July 2007 |
| Creators | Hsiao, Ren-you |
| Contributors | none, none, Tzu-Chien, Hsu, none |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0724107-171236 |
| Rights | restricted, Copyright information available at source archive |
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