In-situ dispersed photopolymerization of cyclic acetals/hydroxyapatite composites: effects of the content of hydroxyapatite.

In this work, hydroxyapatite (HA) was first dispersed into cyclic acetal unit based monomers (EHD), and then EHD/HA composites were obtained by in-situ photopolymerization. FTIR and XRD analyses were used to successfully confirm the chemical composition of this composite. Real-time FTIR revealed that there was no significant effect on the photopolymerization process until the HA content was up to 30%. Several samples of such a composite with different loading amounts of HA were prepared to study effects of HA concentrations on the EHD/HA composite in particular in terms of SEM, TG, DMA, water contact angel and in-vitro biocompatibility. The results appeared that the loading of HA could significantly improve the thermal stability, mechanical properties and in vitro biocompatibility of the EHD/HA composite compared with EHD networks.