聚芳醚酮树脂非等温结晶动力学及其复合材料湿热老化性能EI北大核心CSCD

聚芳醚酮(poly(aryl ether ketone),PAEK)热塑性复合材料因其突出的韧性、耐老化性能、耐疲劳性能,以及成型加工低成本、高效率、可回收等一系列优势,得以替代部分传统热固性复合材料,并已在国外航空等高端工业领域取得成功应用。PAEK是一种半结晶高聚物,复合材料不同的成型工艺条件导致树脂基体聚集态结构的差异,对其力学性能、耐老化性能等均存在显著的影响。对国产PAEK树脂的结晶动力学进行了研究,通过控制成型降温条件,采用模压工艺制备了树脂结晶度不同的连续碳纤维增强复合材料,并对其进行了湿热老化处理,评价了老化处理前后复合材料的弯曲性能。结果表明:采用较大的降温速率能够提高树脂的结晶速率,但会降低树脂的结晶度。在随炉冷却、空气冷却和水冷却三种不同的降温条件下,制备的复合材料结晶度分别约为36.3%,29.7%,26.5%,结晶度的显著差别导致复合材料的弯曲强度随结晶度的降低而减小。经湿热老化处理240 h后的弯曲强度保留率分别为88.8%,86.7%,86.6%,较高的结晶度能够较好地抵抗水对复合材料界面的破坏,提升复合材料的耐湿热老化性能。

Non-isothermal crystallization kinetics of poly(aryl ether ketone) resin and hygrothermal aging properties of its composites

Poly(aryl ether ketone) (PAEK) thermoplastic composites can replace some traditional thermosetting composites because of their outstanding toughness, aging resistance, fatigue resistance, low cost, high manufacturing efficiency and recyclability. Thus, PAEK composites have been successfully applied in foreign aviation and other high-end industrial fields. PAEK is a kind of semi-crystalline polymer. Hence, different molding process conditions of PAEK composites lead to different aggregation structures of resin matrix, which have significant influence on mechanical properties and aging resistance of the composites. Crystallization kinetics of domestic PAEK resin was studied. Then, continuous carbon fiber reinforced PAEK composites with different crystallinities were prepared by mold pressing at different cooling conditions. The composites were subjected to hydrothermal aging treatment. Flexural properties of the composites were evaluated. The results show that higher cooling rates can improve the crystallization rates but reduce the crystallinity of PAEK resin. The crystallinity of PAEK resins of the composites prepared at furnace cooling, air cooling and water cooling are about 36.3%, 29.7% and 26.5%, respectively. Thus, the decrease of PAEK crystallinity leads to the decrease of flexural strength of its composites. Moreover, flexural strength retention rates of composites with different crystallinities after hydrothermal aging treatment for 240 h are 88.8%, 86.7% and 86.6%, respectively. Therefore, higher crystallinity can better resist the damage of water on the interface and improve the hydrothermal aging resistance of the composite.