Poly(vinyl alcohol)/gelatin/nano-hydroxyapatite (PVA/Gel/n-HA) composites were prepared based on solid state shear milling technology (S3M) and plasticization of gelatin obtained by in situ degradation of collagen during extrusion.The structure and thermal-processing properties of the composites were characterized by scanning electron microscopy (SEM)

Fourier transform infrared spectroscopy (FTIR)

differential scanning calorimetry (DSC)

thermogravimetric analysis (TGA) and high pressure capillary rheometry.The results showed that n-HA particles were well dispersed in PVA based matrix by S3M technology.And strong hydrogen bonds formed between PVA and Gel

which may replace the self-inter and intra hydrogen bonds of PVA.The hydrogen bonds not only improved the thermal stability of PVA and increased the initial thermal decomposition temperature (287.6℃) of PVA/Gel/n-HA composite

but also decreased the crystallinity degree (about 24.5%) of PVA so that the melting point (130.5℃) was much lower than its initial thermal decomposition temperature

obtaining the thermal processing windows over 140 K.The gel significantly reduced the apparent viscosity of PVA/n-HA composites and improved the thermal processing properties

offering a new way to prepare PVA/n-HA bioactive composite.