Copolymers of poly(aryl ether ketone)/poly(ether ether amide) containing different numbers of methylene in the main chain: Synthesis and properties

“One-step polymerization method” was used to improve the thermal property of semi-aromatic poly(ether ether amide) (PEEA). Firstly, a series of difluorobenzamide monomers containing different numbers of methylene were synthesized by the reaction of diamine and 4-fluorobenzoic chloride using a facile interfacial reaction method. Then, these syntheses were conducted to react with bisphenol AP and 4,4′-difluorobenzophenon to synthesize the novel poly(aryl ether ketone)/semi-aromatic poly(ether ether amide) copolymers (PAEK/PEEA) with different chain lengths in the chain through nucleophilic substitution by a one-step method. The obtained copolymers were amorphous with inherent viscosities of 0.373–0.433 dLg −1 . They were found to have high glass transition temperatures (T g ) of 160–191°C, good thermal stability with 5% weight-loss temperature (T 5% ) of 409–437°C. The tensile strengths of the copolymers were 65.0–75.8 MPa. The storage modulus were over 0.9 GPa at 120°C. At room temperature, the copolymers were soluble in NMP, slightly soluble in DMF, CH 2 Cl 2 , CH 3 Cl, indicating that the synthesized copolymers could be processed by solution method. The results of optical performance showed that the copolymers had good optical transmittance with the optical transmittance of 75.7%–86.1% at 450 nm. They have the potential to be applied as the novel heat-resistance optical films as the novel copolymers.