Study on compressive mechanical properties of nanohydroxyapatite reinforced poly(vinyl alcohol) gel composites as biomaterial.

Nanohydroxyapatite reinforced poly(vinyl alcohol) (nano-HA/PVA) gel composites has been proposed as a promising biomaterial to replace diseased or damaged articular cartilage. In this paper, nano-HA/PVA gel composites were prepared by in situ synthesis nano-HA particles in PVA solution and accompanied with freeze/thaw method. The influence of nano-HA content, PVA concentration and freeze/thaw cycle times on the compressive mechanical behavior of nano-HA/PVA gel composites were evaluated using mechanical test equipment. The results showed that the compressive mechanical behavior of nano-HA/PVA gel composites was similar to that of natural articular cartilage, which held special viscoelastic characteristics. Both the compressive strength and modulus of the composites improved correspondingly with the rise of freeze/thaw cycle times and PVA concentration. The compressive strength and modulus of nano-HA/PVA gel composites firstly increased and then presented decreasing trend with the rise of nano-HA content. Furthermore, the compressive modulus of the composites improved exponentially with the rise of compressive strain ratio.