Effect of Preparation Methods on Mechanical Properties of PVA/HA Composite Hydrogel

Poly(vinyl alcohol) (PVA) / hydroxyapatite (HA) composite hydrogel specimens were prepared with 15% PVA and 1%, 2%, 3%, 4% and 5% HA by repeated freezing-thawing. The tests of static and dynamic mechanical properties were carried out to discuss the influence of different contents of HA and freezing-thawing cycles on the mechanical properties of PVA/HA composite hydrogel. The results of static mechanical tests showed that the PVA/HA composite hydrogel with 3% HA and nine freezing-thawing cycles had excellent stress relaxation properties, higher relaxation ratio, lower stress equilibrium value and presented better properties of creep and recovery. The results of dynamic mechanical test showed that the PVA/HA composite hydrogel with nine freezing-thawing cycles had higher storage modulus and loss modulus, so was the PVA/HA composite hydrogel with 3% HA.