Study on the Melt Memory Effect and Melt Recrystallization Behavior of Crystallizable Biphenylene Poly(arylene ether sulfone ketone)
Xin Liu, Yingshuang Shang, Qinfei Xu, Chenyi Zhou, Haibo Zhang, Xuanbo Zhu
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 Tg 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 Tg 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.