| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 93 === In this study, nanoporous polyhedral oligomeric silsesquioxane (POSS) molecules, were covalently tethered to the imide oligomer and copolyimide to form POSS/polyimide nanocomposites in two methods. The solubility properties, thermal properties and the dynamic mechanical properties of the POSS/polyimide nanocomposites were investigated by varying the weight ratio of POSS.
First, the imide nanooligomer, were prepared via the solution condensa-
tion of aromatic dianhydrides with POSS-4-aminobenzene, and added it by different ratio into polyimide, and gave flexible and tough films via solvent casting. The films had tensile strength of 103~127 MPa, and elongation to breakage values of 19~145%.The DMA analysis reveals that the glass transition temperatures ranged from 242 to 255℃. In addition, the temperat-
ures of 10% weight loss in nitrogen and the air ranged on 512~522℃ and 505~523℃, respectively.
Second, a series of polyimide nanocomposites were prepared by reaction of different ratio 1,4-Bis(4-aminophenoxy)-2-(4-POSS-benzyloxy)-
benzene, and 1,4-Bis(4-aminophenoxy)-2-tert-butylbenzene with aromatic tetracarboxylic dianhydride. The polymer were prepared with moderate to high inherent viscosities 0.32~1.2 dL/g, and number average molecular weight 1.4~7.4*104. The obtained copolyimides were readily soluble in common organic solvents and gave flexible and tough films via solvent casting. The films had tensile strength of 37 ~ 93 MPa , and elongation to breakage values of 3 ~ 197 % .The DMA analysis reveals that the glass transition temperatures ranged from 245 to 258℃. In addition, the temperat-
ures of 10% weight loss in nitrogen and the air ranged on 495~517℃ and 475~516℃, respectively.
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