Synthesis And Characterization Of Aromatic Polyamides Containing Ether Ketone Structure

PAEK and aromatic polyamides are two kind special engineering plastics whichshowed advantages and disadvantages in different application field. The PAEKshowed a low transition temperature due to its molecular structure, which limits itsapplication in the high temperature environment. The force and rotational resistanceof intermolecular chain will increase due to the presence of amide bond in the, but itdeteriorate the solubility of the aromatic polyamides material. Based on considerationof this issue dialectic, Introduce the amide bond to the PAEK will increased the glasstransition temperature and improve the temperature limit, on the other hand, introducethe ether ketone structure to the aromatic polyamides will damage the regularity of thechain structure and reduce hydrogen bonding interaction to improve the solubility.Based on this consideration, we design and synthesis of diamine monomer whichcontaining ether ketone structure, combine the advantages of PAEK and aromaticpolyamides, ameliorate the disadvantages of two kinds of polymers.The first part of this thesis was successfully synthesized monomer4,4’-bis (4-aminophenoxy) benzophenone (4BABP) and characterized by FT-IR, NMR, MS,DSC. Synthesized a series of aromatic polyamides which containing ether ketonestructure by low-temperature synthesis method and its structure was characterized byFT-IR, NMR. Ubbelohde viscometer was used to determine the molecular weight andsolubility. The thermal performance test was using DSC, TGA, DMA. The test of filmon the surface morphology was characterized through SEM. XRD studied the state ofaggregation. The results showed that the synthesized aromatic polyamides all havinghigh glass transition temperature and good heat resistance, extremely excellentmechanical properties Due to the regularity of molecular chain segments, PEKA-1and PEKA-2were solvent induced molecular chain rearrangement to form asemicrystalline polymer film. PEKA-1and PEKA-2showed poor solubility because of the regularity of molecular chain segments and the strong interaction between themolecular chain, which soluble in the presence of lithium chloride and calciumchloride dissolved in DMAc or NMP.In the second part of this thesis, a novel compound of4,4’-bis(4-amino-3-trifluoromethylphenoxy)benzophenone was successful synthesized, then, a seriesaromatic polyamide which were high molecular, contain trifluoromethyl and etherketone were obtained through condensation reaction at low temperature. Further, thestructure properties of the monomer and polymer were characterized by FT-IR, NMR.Ubbelohde viscometer was used to determine the molecular weight, solubility,film-forming properties and mechanical properties. XRD studied the state ofaggregation. The dielectric constant and water contact angle were detected bydielectric constant detector and hydrophobic angle tester. The solubility andprocessing conditions of the aromatic polyamide were improved, the hydrophobic andhydrophilic properties of the polymer-film were improved and the dielectric constantwas decreased as a result of the introduction of trifluoromethyl. In addition, the seriesaromatic polyamides were thermal stability, film-forming ability and very excellentmechanical properties.The results of this thesis provide ideas and guidance to how to improveworkability and dielectric properties of the corresponding aromatic polyamide whilemaintaining thermal properties and mechanical properties were without losing.