Synthesis And Properties Of Novel Heterocyclic Poly(Aryl Ether Ketone)s Containing Naphthalene Moiety

Poly(aryl ether ketone)s are well known as high performance polymer materialwhich possess excellent comprehensive properties. They are widely used inaerospace, electronic, precision machinery and the other fields closely related tonational safety and high technology development. In recent years, poly(aryl etherketone)s exhibit wide application prospects on efficient energy storage andconversion fields such as fuel cells and dielectric energy storage. However, poly(arylether ketone)s also exhibit several shortcomings such as high preparation cost,insoluble, processing difficult, limited heat-resistant grade and so on, so thesynthesis of poly(aryl ether ketone)s with more excellent comprehensive propertieshas been a focus of the people. Based on the research of poly(aryl ether ketone)scontaining asymmetric structural aromatic heterocyclic and naphthalene moiety,synthesis of the novel heterocyclic poly(aryl ether ketone)s containing naphthalenemoiety is an important research direction. In this paper, a series of novel heterocyclicpoly(aryl ether ketone)s containing naphthalene moiety were synthesized. Therelationship between chemical structure and properties of the polymers wasresearched, and the specific research work was carried out as follows:1. A series of2,6-naphthalenedicarboxylic acid-based novel heterocyclic poly(aryl ether ketone)s (3a-3e) were synthesized by the novel N-C couplingpolymerization of actived difluoride monomer2,6-bis-(4’-fluorinebenzoyl)-naphthalene and bisphenol-like containing phthalazinone (2a-2e). The activeddifluoride monomer was synthesized by two-step reaction from2,6-naphthalene-dicarboxylic acid. The structure of the difluoride monomer and polymers werecharacterized by FT-IR and~1H NMR. The results indicated that we successfullysynthesized the target monomer and polymers. The polymers exhibited good subilityin aprotic polar organic solvent at room temperature, such as Chloroform, DMAc,NMP and so on, and the chloroform solution of these polymers could be cast intotransparent and flexible films. The thermal properties of the polymers wereinvestigated by DSC and TGA, the glass transition temperature of the polymers were in the range of243-265℃, the5%and10%weight loss temperatures of thesepolymers were in the range of450-515℃and466-544℃in nitrogen, respectively,and the residual weight were all above62%at800oC in nitrogen.2. A series of2,6-dimethylnaphthalene-based novel heterocyclic poly(aryl etherketone)s (3a-3f) were synthesized by the novel N-C coupling polymerization ofactived difluoride monomer1,5-bis-(4’-fluorinebenzoyl)-2,6-dimethylnaphthaleneand bisphenol-like containing phthalazinone (2a-2f). The actived difluoridemonomer was synthesized by Friedel-Crafts acylation of2,6-dimethylnaphthaleneand4-fluorobenzoyl chloride. The structure of the difluoride monomer and polymerswere characterized by FT-IR and~1H NMR. The results indicated that we successfullysynthesized the target monomer and polymers. The thermal properties of thepolymers were investigated by DSC and TGA, and the solubility and inherentviscosities (ηinh) were also investigated. The results indicated that the glass transitiontemperature of the polymers were all over280℃, the5%and10%weight losstemperatures of these polymers were in the range of423-440℃and434-467℃innitrogen, respectively, and the residual weight were in the range of53%-69%at800oC in nitrogen. The polymers exhibited good subility in aprotic polar organic solventat room temperature, and the polymer solution could be cast into flexible andtransparent films. The novel heterocyclic poly(aryl ether ketone)s is a highperformance polymer material which exhibit excellent comprehensive properties,and could be used to synthesize fuel cell anion exchange membrane by the derivativefunction of the side methyl.