Improving the interfacial properties of carbon fiber/low melting point PAEK composites by embellishing of bio-based PAEK sizing agent

In this study, a bio-based polyarylene ether ketone (bio-PAEK) was synthesized to prepare water-based sizing agents for enhancing the interfacial adhesion between carbon fiber (CF) and matrix. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) results indicated that the bio-PAEK exhibited good thermal properties. To improve the processability and reduce the processing temperature, PAEK with a low melting point (LMPAEK) was also used as the matrix resin. The glass-transition temperature (Tg) of LMPAEK was slightly higher than that of polyether ether ketone (PEEK), but its melting temperature (Tm) was lower 48.5 °C. A strong interface was created after introducing sizing agents onto the CF surface due to good compatibility between fibers and matrix. The interlaminar shear strength (ILSS), interfacial shear strength (IFSS) and flexural strength of CF2/LMPAEK composites increased by 54.7%, 56.0% and 46.6%, respectively, compared with the untreated composites. This study provided a novel approach to prepare water-based bio-PAEK sizing agents for CF composites with a low melting point matrix to be applied in additive manufacturing.