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

Abstract“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 (Tg) of 160–191°C, good thermal stability with 5% weight‐loss temperature (T5%) 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, CH2Cl2, CH3Cl, 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.