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Title page for etd-0811104-132550


URN etd-0811104-132550 Statistics This thesis had been viewed 2591 times. Download 8 times.
Author Mei-Yuan Hsu
Author's Email Address yuan200178@yahoo.com.tw
Department Chemical Engineering
Year 2003 Semester 2
Degree Master Type of Document Master's Thesis
Language English Page Count 116
Title SYNTHESIS AND PROPERTIES OF NOVEL POLYIMIDES CONTAINING CYCLIC CARDO OR 2,5-DI-TERT-BUTYLBENZENE GROUP
Keyword
  • thermal imidization
  • polyimide
  • polyimide
  • thermal imidization
  • Abstract First, a novel fluorinated bis(ether amine) monomer, 5,5-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]-4,7-methanohexahy-droindan (2), was prepared through the nucleophilic aromatic substitution reaction of 5,5-bis-(4-hydroxylhpenyl)-4,7-methanohexahydroindan with 2-chloro-5-nitrobenzotrifluoride to yield the intermediate dinitro compound, followed by catalytic reduction with hydrazine and Pd/C. Polyimides (PIs, 5a-f) were synthesized from 2 and various aromatic dianhydrides (3a-f) using a standard two-stage process with chemical or thermal imidization of poly(amic acid). PI 5a-f had inherent viscosities ranging from 0.64 to 0.86 dL/g. All of PIs were soluble in amide-type solvents above 10% wt/V. These PI films had tensile strengths of 93-117 MPa, elongations to break of 7-17%, and initial moduli of 2.0-2.8 GPa. The glass transition temperatures of 5 were 255-307 ℃, and the 10% weight loss temperature was above 464 ℃, with their residues more than 46% at 800 ℃ in nitrogen. Compared with the nonfluorinated PI-6, 5 series was observed to have lower dielectric constants (2.92-3.28 at 1 MHz), lower moisture absorptions (0.15-0.43 wt%), and lower color intensity. Second, a series of poly(ether imide)s (PEIs) 6’a-k with light color and good physical properties were prepared from 1,4-bis(3,4-dicarboxypheoxy)-2,5-di-tert-butylbenzene dianhydride (3’) with various aromatic diamines (4’a-k) via a conventional two-stage procedure that included a ring-opening polyaddition to give poly(amic acid)s (PAAs), followed by thermal imidization to the PEI. The intermediate PAA had inherent viscosities in the range of 1.00-1.53 dL/g. Most of PEIs showed excellent solubility in chloroinated solvents such like dichloromethane and chloroform and m-cresol, but not easily dissolved in dimethylsulfoxide and amide-type polar solvents. 6’ series had tensile strengths of 93-118 MPa, elongation at break of 7-18%, and initial moduli of 2.0-2.5 GPa. The softening temperatures (Ts) and the glass transition temperatures (Tg) of the 6’ series were recorded between 216-279 ℃ and 232-285 ℃, respectively. The decomposition temperatures for 10% weight loss all occurred above 487 ℃ in nitrogen or air. The 6’ series showed low dielectric constants (2.71-3.54 at 1 MHz), low moisture absorption (0.18-0.66 wt%), light-colored, with an cutoff wavelength below 385 nm and low yellow index (b*) values of 7.3-14.8. Third, a series of poly(ether imide)s (PEIs) 6”a-h characterized by colorlessness, high transparency, high solubility, and good mechanical properties, were synthesized from the aromatic dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)-2,5-di-tert-butylbenzene dianhydride (3”) and various aromatic diamines 4”a-h with pendent trifluoromethyl group via polyaddition, chemical imidization, and direct casted films. The PEI had inherent viscoseties in the range of 0.43-1.25 dL/g. The PEI of 6” series showed more colorless than the PIs of 2,2-bis(3,4-dicarboxyphenyl)hexa-
    fluoropropane dianhydride (6FDA)-derived 8” and 9” series, the latter being synthesized from the CF3-containing diamines with 6FDA. The films of 6” had cutoff wavelengths (λo) between 371 and 380 nm, as well as b* value (a yellowness index) ranging from 3.7 to 6.6. All of PEIs showed excellent solubility in organic solvents. They were soluble in N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, pyridine, tetrahydrofuran, even dichloromethane and chloroform at 5-10% wt/V. These PEI films showed tensile strengths of 100-116 MPa, elongations at break of 8-20%, initial moduli of 2.0-2.2 GPa. The softening temperatures and the glass transition temperatures of the 6” series were recorded between 219-284 ℃ and 230-305 ℃, respectively. The decomposition temperatures for 10% weight loss all occurred above 478℃. When compared with the corresponding nonfluorinated 7”, the 6” series showed better solubility and lighter color than the 7” series.
    Advisor Committee
  • Chin-Ping Yang - advisor
  • Guey-Sheng Liou - co-chair
  • Li-Tang Teng - co-chair
  • Sheng-Huei Hsiao - co-chair
  • Files indicate in-campus access only
    Date of Defense 2004-07-23 Date of Submission 2004-08-11


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