Morphology of polycaprolactone/needle-shaped hydroxyapatite (PCL/HAN) nanocomposite blends using ultrasound assisted melt blending

Polycaprolactone/Hydroxyapatite (PCL/HA) composite is an excellent material for fabricating tissue engineering scaffolds, especially as bone scaffolds. However, polarity differences between the hydrophilic HA and the hydrophobic PCL often leads to poor dispersion during the blending process. This is due to the tendency of the HA particles to agglomerate, and the difficulty to efficiently mix the polymer melt at high loading. The objective of this study is to introduce ultrasound waves during the conventional melt blending to overcome the problem. PCL and needle-shaped hydroxyapatite (HAN) were blended using an ultrasonically assisted extruder. The morphology of the PCL/HAN blend was investigated using field emission scanning electron microscopy (FESEM). This study found that the presence of ultrasound waves during melt blending was helpful in breaking up the HAN agglomerates. Thus, better dispersion of HAN was obtained, although some small agglomerates of HAN were still observed.