Study on crystallisation of nano-hydroxyapatite/polyvinyl alcohol composite hydrogel

Abstract

AbstractComposite hydrogels of nano-hydroxyapatite (n-HA)/polyvinyl alcohol (PVA) were prepared by solution and freeze thawing methods in this paper. The effect of different n-HA content on PVA melting point, crystallinity and mechanical property was studied. Differential scanning calorimetry measurement exhibited a decrease in the crystallisation temperature and crystallinity of PVA with the addition of n-HA. The reason should be that hydrogen bonds in PVA macromolecule are destroyed when PVA form bonding with n-HA, thus suppressing the crystallisation of PVA polymer chains. Mechanical property test of the composite hydrogels reveals that the tensile strength is correlated with PVA crystallisation; the higher the crystallisation of PVA, the greater the tensile strength. The n-HA also lowers the water absorption ratio of PVA hydrogel.Keywords: NANO-HYDROXYAPATITEPOLYVINYL ALCOHOLHYDROGELCRYSTALLISATION