Synthesis And Properties Of Novel Polyaryletherketones, Polyarylamides And Polyarylesters Containing Xanthene Structures

In this dissertation, the resent progress on the study of poly(aryl ethe rketone)s and polyarylamides was investigated. The main contents were described as follow.1. Xanthenone was prepared in 79.5% yield from 2-methyl diphenylether as original material through two-step reaction of oxidation using KMnO₄ as oxidant and subsequent cycloacylation promoted by concentrated sulfuric acid. Then reaction of xanthenone with sulfur oxychloride, followed by substitution reaction with phenol to afford a new biphenol monomer containing xanthene structure——9, 9-bis(4-hydroxyphenyl)xanthene in 69.5 % overall yield based on 2-methyl diphenylether. Five novel poly(aryletherketone)s containing xanthene structures in main chain were prepared by high temperature solution polycondensation from 9, 9-bis(4-hydroxyphenyl)xanthene with 4,4'-difluorobenzophenone, 1,4-di(4-fluorobenzoyl)benzene, 1,3-bis(4-fluorobenzoyl)benzene, 4,4'- bis(4-fluorobenzoyl)biphenyl and 4,4'- bis(4-fluorobenzoyl)diphenyl ether in the presence of K₂CO₃ / tetramethylene sulfone as catalyst/solvent complex system under N2 atmosphere, respectively. These new polymers have been characterized by FT-IR, DSC and WAXD, etc. The results showed that all the PAEKs are non-crystalline, exhibit high Tg (210-254 ^oC) and good heat-resistance. The onset temperature taken at 5 % weight loss of the polymers in nitrogen was all over 525 ^oC. All the polymers formed transparent, strong, and flexible films, with tensile strengths of 104.3-108.5 MPa MPa, tensile moduli of 2.48-2.65 GPa, and elongations at break of 22 -31 %. All the polymers were soluble in organic solvents such as NMP, THF and CHCl3 at room temperature.2. Substitution reaction of 9, 9-bis(4-hydroxyphenyl)xanthene (1) with 4-fluorobenzonitrile (2) formed 9, 9-bis(4-cyanophenoxyphenyl)xanthene (3) in 88.7 % yield, which was hydrolyzed in C₂H₅OH in the presence of KOH to give 9, 9-bis(4-carboxyphenoxyphenyl)xanthene (4), followed by treatment with sulfur oxychloride to yield polymerization-grade monomer 9, 9-bis(4-chloroformylphenoxyphenyl)xanthene (4). The overall yield of the three-step reaction for (4) was 73.0 %.3. Seven kinds of novel polyamides containing xanthene structures in main chain with inherent viscosities of 0.86-1.25 dL/g were synthesized from p-phenylenediamine, m-phenylenediamine, bis(4-aminophenyl)methyl, 4,4'-biphenyldiamine, 4,4'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene and 9, 9-bis(4-chloroformylphenoxyphenyl)xanthene by low temperature solution polycondensation under N₂ atmosphere, respectively. The prepared polyamides containing xanthene structures with inherent viscosities of 0.86-1.25 dL/g exhibit excellent heat-resistance. The Tgs of these polymers were ranged from 226 ^oC to 288 ^oC. The onset temperature taken at 5 % weight loss of these polymers in nitrogen was all over 522 ^oC. These polymers with tensile strength of 86.0-118.4 MPa ,elongation at break of 6.0-7.4 % and tensile modulus of 2.86-3.65 GPa. These polymers were soluble in strongly polar organic aprotogenic solvents such as DMF, DMSO and NMP at room temperature.4. Four novel polyarylesters containing xanthene structures in main chain with high molecular weight were synthesized from hydroquinone, resorcinol, bis(4-hydroxyphenyl)methane and 2,2-bis(4-hydroxyphenyl)propane with TCTPC in 1,2-dichloroethane by solution polycondensation in the presence of pyridine under N₂ atmosphere, respectively. Three polymers were by FT-IR, DSC, TG. The results showed that these new polyarylesters exhibit excellent heat-resistance. The onset temperature taken at 5% weight loss of the polyarylesters in nitrogen was in range of 417 ^oC- 454 ^oC. The polymers were soluble in concentrated H₂SO₄, NMP and 1,2-dichloroethaneat room temperature.