Effects of molecular weight on the dynamic mechanical properties and interfacial properties of carbon fiber fabric-reinforced polyetherketone cardo composites

Abstract

It’s a long-standing task to explore the toughening effect of fiber-reinforced thermoplastic composites, which could be used to produce new materials demanded by the aerospace field. In this work, we investigated the effects of the molecular weight of a thermoplastic resin, polyetherketone cardo (PEK-c), on the thermal, mechanical, and interfacial properties of the composite. Carbon fiber fabrics reinforced with PEK-c composite laminates were prepared by solution-processed prepreg and hot press molding. Scanning electron microscopic results showed that the fibers were distributed uniformly in the resin, with no visible flaws detected. The results of the dynamic mechanical analysis revealed that, according to the lower mobility of the polymer chain, the glass transition temperature of composite laminates increased with the increase in molecular weight. However, the tan δ values showed a lower peak value with a higher molecular weight due to the improved interfacial property between the resin and the fiber. The results on interlaminar shear strength also indicate that composites with resins of higher molecular weight have better interfacial adhesion. These results are closely interrelated with and contribute to our overall understanding of the effects of molecular weight on the properties of CFRP composites.