| Summary: | 碩士 === 國立成功大學 === 化學工程學系碩博士班 === 93 === Part I, A CF3-containing diamine, 1,4-bis(4-amino-2-trifluoromethylphenoxy) benzene (I), was prepared from hydroquinone and 2-chloro-5-nitrobenzotrifluoride. And the imide-containing diacids (Va~h and VIa,b) were prepared by condensation reaction of amino acids, aromatic diamines and trimellitic anhydride. Then, a series of soluble fluorinated polyamides (PA, Code: VIIa~h) and poly(amide-imide)s (PAI, Code: VIIIa~h and Xa,b) were synthesized from the diamine I with various aromatic diacids (IIa~h) and the imide-containing diacids (Va~hand VIa,b) via direct polycondensation with triphenyl phosphate and pyridine. The polyamides (PA) and polyamide-imides (PAI) had inherent viscosities of 1.00-1.70 dL/g and 0.79-1.34 dL/g, respectively. All synthesized polymers showed excellent solubility in amide-type solvents such as N-methyl-2-pyrrolidinone, N, N-dimethylacetamide and N-dimethylforamide and afford transparent and tough films by solvent casting. Polymers films VIIa~h, VIIIa~h, Xa,b had tensile strengths of 91-113 MPa, elongations to break of 8-40 %, and initial moduli of 2.1-2.8 GPa. The glass transition temperature of PAs and PAIs were in the range of 254-276 oC and 255-292 oC, respectively, and the imide-containing PAIs had better thermal stability than PAs. PAs showed higher transparency and were much lighter in color than PAIs, and their cutoff wavenumber (λ0) were below 400 nm. In comparison with the isomeric IXc-h, the PAIs (VIIIc-h) exhibited less coloring and showed a lower b* (yellowness index) values than the corresponding IX series. Part II, A new tetraimide-dicarboxylic acid (IV’) was synthesized starting from ring-opening addition of 4,4�S-oxydiphthalic anhydride (ODPA), trimellitic anhydride (TMA), and 1,4-bis(4-amino-2-trifluoromethylphenoxy) benzene (BAFPB) at a 1: 2: 2 molar ratio in N-methyl-2-pyrrolidone (NMP). A series of fluoride, organosoluble poly(amide-imide-imide)s (PAII; code VII’a-j ) with inherent viscosities of 0.72-0.96 dL/g were prepared by triphenyl phosphite-activated polycondensation from the tetraimide-diacid with various aromatic diamines. All of the polymers were readily soluble in a variety of organic solvents such as NMP, N,N-dimethyl acetamide (DMAc) and even in less polar m-cresol and pyridine. These polymers afforded tough, transparent, and flexible films, which had tensile strengths ranging from 99 to 125 MPa, elongations at break from 12 to 19 %, and initial moduli from 1.6 to 2.4 GPa. The glass transition temperatures of polymers recorded at 236-276 oC. They had 10 % weight loss temperatures in the range of 504-559 oC in nitrogen and 499-544 oC in air, respectively, and left more than 54 % residue even at 800 oC in nitrogen, indicating excellent thermal stability.
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