SYNTHESIS AND PROPERTIES OF FLUORINATED POLYIMIDES BASED ON FLUORINE-CONTAINING DIETHERAMINES EXTENDED FROM BISPHENOL-A AND HEXAFLUORO-BISPHENOL-A

• Main Authors: Kuei-Hung Chen, 陳奎宏
• Other Authors: Chin-Ping Yang
• Format: Others
• Language: en_US
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/93362123498471182904

碩士 === 大同大學 === 化學工程研究所 === 90 === First, a novel fluorinated diamine monomer, 2,2-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]propane (2), was prepared through the nucleophilic substitution reaction of 2-chloro-5-nitrobenzotrifluoride with 2,2-bis(4-hydroxyphenyl)propane in the presence of potassium carbonate, followed by catalytic reduction with hydrazine and Pd/C. Polyimides were synthesized from diamine 2 and various aromatic dianhydrides 3a-f via thermal imidization. These polymers had inherent viscosities ranging from 0.73 to 1.29 dL/g. Polyimides 5a-f were soluble in amide polar solvents and even in less polar solvents. Polyimide films 5a-f had tensile strengths of 87-100 MPa, elongations to break of 8-29%, and initial moduli of 1.7-2.2 GPa. The glass transition temperatures of these polymers were in the range of 222-271℃, and the 10% weight loss temperatures of them were all above 493℃. Their films had cutoff wavelengths between 363-404 nm, b* values ranging from 8 to 62, dielectric constants of 2.68-3.16 (1 MHz), and moisture absorptions in the range of 0.04-0.35 wt%. Second, A series of soluble and light-colored fluorinated polyimides (5’) were synthesized from 2,2-bis[4-(4-amino-2- trifluoromethylphenoxy)phenyl]hexafluoropropane (2’) and various aromatic dianhydrides (3’a-f) via thermal imidization. Diamine 2’ was prepared starting from 2-chloro-5-nitrobenzotrifluoride and 2,2-bis(4-hydroxyphenol)hexafluoropropane to yield the intermediate dinitro compound, followed by catalytic reduction with hydrazine and Pd/C. These polymers had inherent viscosities ranging from 0.80 to 1.19 dL/g. Polyimides 5’a-f were soluble in amide polar solvents and even in less polar solvents. Polyimide films 5’a-f had tensile strengths of 78-93 MPa, elongations to break of 8-16%, and initial moduli of 1.7-2.1 GPa. The glass transition temperatures of these polymers were in the range of 221-265℃, and the 10% weight loss temperatures were above 493℃. Their films had cutoff wavelengths between 343-390 nm, b* values ranging from 5 to 41, dielectric constants of 2.68-3.01 (1 MHz), and moisture absorptions in the range of 0.03-0.29 wt%.