Study on the Melt Memory Effect and Melt Recrystallization Behavior of Crystallizable Biphenylene Poly(arylene ether sulfone ketone)

Abstract

Poly(arylene ether sulfone) resins are usually a class of amorphous polymers, which makes them inferior to other semicrystalline aromatic polymers in solvent resistance, chemical stability, and mechanical strength. Herein, a crystallizable poly-(arylene ether sulfone ketone) with a high biphenylene content (BD-PESK) was designed and synthesized. BD-PESK showed excellent thermal stability with a T g of 241 °C and 5% weight loss temperature of 548 °C. Meanwhile, BD-PESK exhibited an obvious melt memory effect at 350−370 °C, but a weak melt memory effect would survive even above its equilibrium melting point due to the high segment rigidity. Under the guidance of this effect, the melt recrystallization of BD-PESK with a maximum crystallinity of 23% can be realized effectively, which made it have excellent solvent resistance similar to the PEEK resin. Semicrystalline BD-PESK showed a high tensile strength up to 86 MPa with a good elongation at break of 23%. Furthermore, due to the combination of high T g and semicrystallinity, BD-PESK could maintain 71% storage modulus at 240 °C and still 1.4% storage modulus at 300 °C, respectively, showing superior heat resistance to most thermoplastic polymers.

Melt memory in random ethylene-1-alkene copolymers

“…Recently, the melt memory effect above T 0 m in rigid poly(arylene ether sulfone ketone) homopolymers has been reported. 36 In general, this strong melt memory has not been previously observed in flexible homopolymers.…”

Origin of Melt Memory Effects in Poly(ethylene oxide): The Crucial Role of Entanglements

“…Thus, in order to obtain an isotropic melt, temperatures higher than T m ° are needed to homogenize the heterogeneous melt structure. More recently, melt memory effect above T m ° for rigid poly(arylene ether sulfone ketone) [ 47 ] has also been reported. In general, such a strong melt memory has not been previously observed for flexible homopolymers.…”

Synergistically Improving the Thermal Conductivity and Mechanical Strength of PEEK/MWCNT Nanocomposites by Functionalizing the Matrix with Fluorene Groups

“…After glass transition temperature, G' of i-FD2-P10M was slightly lower than that of i-P10M, which was mainly affected by the crystallinity of the copolymers. [45] Nanocomposites can also be used as a matrix to prepare multi-component composites. Following our previous work, a double segregated network composite i-PEEK/MWCNT@GNS was prepared by replacing the matrix with the fluorene-functionalized PEEK/MWCNT nanocomposite.…”

“…After glass transition temperature, G ’ of i‐FD2‐P10M was slightly lower than that of i‐P10M, which was mainly affected by the crystallinity of the copolymers. [ 45 ]…”