Nucleated nanocomposites of TPU–PDMS blends based on spherical nanohydroxyapatite

Abstract

The present investigation gives a profound insight into the preparation of nucleated nanocomposites of TPU–PDMS blends based on uniquely synthesized PPG-wrapped spherical nanohydroxyapatite (nHap). The spherical nHap at different doses of 1, 3, 5 and 7 phr in different blends of 90 : 10, 80 : 20, 70 : 30, 60 : 40, and 50 : 50 (TPU : PDMS) were prepared. Based on the mechanical properties of the nanocomposites as well as their scope in the field of biomedical applications, detailed studies were carried out for the 70 : 30 blend (T70P30) nanocomposites. The effect of nHap on the mechanical and thermal properties of the T70P30 blend has been thoroughly analysed by using a universal testing machine (UTM), dynamic mechanical analyser (DMA), differential scanning calorimetry (DSC) and a thermogravimetric analyser (TGA). The incorporation of nHap into the T70P30 blend is promoted by the enhanced nucleation effect and has shown a considerable improvement in the tensile strength, storage modulus and thermal stability over the neat blend. The enhancements in these properties are due to better dispersion, which has been confirmed by field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). DSC revealed the role of filler dosage in nucleation efficiency of nanocomposites. X-ray diffraction (XRD) studies were also carried out for the structural analysis and observed an increasing trend in crystallinity of the nanocomposite with filler dosage. The crystallinity, T_g and ΔH values of the nanocomposites with 7 phr nHap (T70P30H7) met the properties of pristine TPU.