| Summary: | 碩士 === 大同大學 === 化學工程研究所 === 90 === This thesis has been divided into two parts. Part 1 deals with the synthesis and properties of fluorinated polyimides based on fluorine-containing dietheramines extended from catechol. A novel fluorinated diamine monomer, 1,2-bis(4-amino-2-trifluoromethylphenoxy)benzene (II), was prepared through the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride with catechol in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Polyimides V were synthesized from diamine II and various aromatic dianhydrides IIIa-f via thermal imidization. These polymers had inherent viscosities ranging from 0.68 to 0.76 dL/g and were soluble in a variety of organic solvents such as NMP, DMAc, DMF, and DMSO, and some even could be dissolved in less polar solvents such as m-cresol, pyridine, and dioxane. Polyimide films Va-f had tensile strengths of 92-123 MPa, elongations to break of 8-42%, and initial modulus of 2.0-2.4 GPa. The glass transition temperatures of these polymers were in the range of 223-277℃, and no significant weight loss was observed below a temperature of 520℃ in nitrogen or in air. Compared with nonfluorinated homologues VI, polyimides V showed better solubility and lower color intensity, dielectric constant, and moisture absorption. Low dielectric constants (2.70—3.62 at 1 MHz) and low moisture absorptions (0.06-0.26 wt%) were also observed. In particular, Vc-f afforded lightly colored films, which had cutoff wavelengths lower than 395 nm and b* values ranging from 10 to 25. Part 2 deals with the synthesis and properties of fluorinated polyimides based on fluorine-containing dietheramines extended from phenolphthalein. A novel fluorinated diamine monomer, 3,3-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]phthalide (II), was prepared through the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride with phenolphthalein in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Polyimides V were synthesized from diamine II and various aromatic dianhydrides IIIa-f via thermal or chemical imidization. These polymers had inherent viscosities ranging from 0.63 to 0.95 dL/g and were soluble in a variety of organic solvents such as NMP, DMAc, DMF, and DMSO, and even in less polar solvents such as m-cresol, pyridine, and dioxane. Polyimide films Va-f had tensile strengths of 105-125 MPa, elongations to break of 9-12%, and initial modulus of 2.35-2.65 GPa. The glass transition temperatures of these polymers were in the range of 259-320℃, and no significant weight loss was observed below a temperature of 500℃ in nitrogen or in air. Compared with nonfluorinated homologues VI, polyimides V showed better solubility and lower color intensity, dielectric constant (2.70-3.11 at 1 MHz), and moisture absorption (0.12-0.27 wt%). In particular, Vc-f afforded lightly colored films, which had cutoff wavelengths lower than 380 nm and b* values ranging from 9 to 25. On comparing thermal imidized polymers with chemical imidized ones, films Va-f(C) showed a lower color intensity than Va-f(H) did.
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