Synthesis And Properties Of Novel Aromatic Poly(Ether Ketone)s And Polyamides Containing Trifluoromethylphenoxy Pendant

In this dissertation, the resent progress on the study of poly(aryl ethe rketone)s and polyarylamides was investigated. This paper was mainly composed of four parts as follow.1. 2-(4-Trifluoromethylphenoxy)paradimethylbenzene (TFDMB) was prepared in three-step reaction of condensation, oxidation and acylation using 2,5-dimethylphenol and 1-chloro-4-trifluoromethyl benzene as original materials in NMP in the presence of KOH and K2CO3. The optimum reaction conditions was obtained as follows: 1-chloro-4-trifluoromethyl benzene/2,5-dimethylphenol 1: 1.2 (mol), reaction temperature 140-190 oC, reaction time 18 h. The yield of TFDMB reached 93.68 %. TFDMB was subsequently oxidated into key intermediate, 2-(4-trifluoromethylphenoxy)paraphthalic acid (TFPA) with 75% yield in the presence of KMnO4 in aqueous solution of pyridine and sodium hydroxide in two step, respectively. And then reaction of TFPA with sulfur oxychloride yielded polymerization-grade monomer 2-(4-trifluoromethylphenoxy)terephthalyl chloride (TFTPC) in 92 % yields. The overall yield of the three-step reaction for TFTPC was 64.64 %.2. Several novel poly(aryl ether ketone)s (F-PEKK) containing trifluoromethylphenoxy pendant with inherent viscosities of 0.58-0.61 dL/g were prepared from 2-(4-trifluoromethylphenoxy)terephthalyl chloride (1) with diphenyl ether (2a), 2-methyldiphenyl ether (2b), 3-methyldiphenyl ether (2c), 4,4'-diphenoxydiphenylsulfone (2d), 4,4'-diphenoxybenzophenone (2e), 1,4-bis(4-phenoxybenzoyl)benzene (2f) and 4,4'-bis(β-naphthoxy) diphenylsulfone (2g) in 1,2-dichloroethane in the presence of AlCl3 and NMP by low temperature solution polycondensation, respectively. These fluorinted polymers have been characterized by FT-IR, DSC and WAXD, etc. The results showed that all the F-PEKKs are non-crystalline, exhibit high Tg (172-190 oC) and good heat-resistance. The onset temperature taken at 5 % weight loss of the polymers in nitrogen was all over 480 oC. All the polymers formed transparent, strong, and flexible films, with tensile strengths of 94.3-103.3 MPa, tensile moduli of 2.48-3.06 GPa, and elongations at break of 22 -34 %. All the polymers were soluble in strongly polar organic aprotogenic solvents such as DMF, DMSO and NMP at room temperature.3. A series of novel poly (aryl ether ketone ketone) (PEKK/F-PEKK) copolymers bearing trifluoromethylphenoxy side groups with inherent viscosities of 0.70-0.61 dL/g were prepared by low temperature solution polycondensation of TFTPC, DPE and terephthalyl chloride (TPC) in 1,2-dichloroethane in the presence of AlCl3 and NMP. The copolymers have been characterized by FT-IR, DSC and WAXD, etc. The results showed that the copolymers with tensile strengths of 92.4-94.8 MPa, tensile moduli of 2.58-32.73 GPa, and elongations at break of 24.2 -28 % exhibit excellent heat-resistance (Tds of 5 % weight loss of the polymers in N2 were all over 530 oC) and high Tg (165～172 oC), which was higher than that of commercialized PEEK and PEKK. Raising F-PEKK content in the copolymer increases the Tg, but decreases its Tm and crystallinity. The copolymer was soluble in CHCl3 and strongly polar organic solvents such as DMF and NMP when the F-PEKK content is above 50 (mol) %.4. Five kinds of novel fluornted polyamides with with inherent viscosities of 0.87-0.95 dL/g were synthesized from p-phenylenediamine (2a), m-phenylenediamine (2b), 4,4'-biphenyldiamine (2c), 4,4'-diaminodiphenyl ether (4d), 1,4-bis(4-minophenoxy)benzene (4e), 1,3-bis(4-minophenoxy)benzene (4f) and TCTPC by low temperature solution polycondensation under N2, respectively. The prepared fluorinated polyamides with inherent viscosities of 0.87-0.96 dL/g exhibit excellent heat-resistance. The Tgs of these polymers were ranged from 222 oC to 294 oC. The onset temperature taken at 5 % weight loss of these polymers in nitrogen was all over 440 oC. These polymers with tensile strength of 81.4-108.1 MPa ,elongation at break of 4.8-7.1 % and tensile modulus of 2.26-3.32 GPa.were soluble in strongly polar organic aprotogenic solvents such as DMF, DMSO and NMP at room temperature.