On Prominent β-Phase of PVDF Matrix with 4D Capabilities

In the past decade, hydroxyapatite (HAp) and chitosan (CS) have been used as reinforcement in various thermoplastics (like polyvinylidene fluoride (PVDF), polylectic acid (PLA), etc.) for the development of partially bioabsorbable implants. However, little has been reported on β-phase PVDF matrix-based strands with 4D capabilities for prosthetic applications. This study reports the melt processing by screw extrusion (SE) of 8%-HAp- 2%-CS (by wt.) in the PVDF for the fabrication of strands with prominent β-phase resulting in tuneable performance (mechanical, dielectric properties) for 4D applications. The results suggest that screw speed (SS) 7 rpm and screw temperature (ST) 225 °C for PVDF-HAp-CS composite has Young’s modulus (E) 400.14 MPa, mainly due to prominent β-phase (verified by Fourier transformed infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC) analysis). The outcomes have been supported by Shore D hardness, scanning electron microscopy (SEM) based morphological analysis at cross section and lateral surface of prepared strands.