Preparation of polyoxymethylene/hydroxyapatite nanocomposites by melt processing

Abstract

Hydroxyapatite (HAp, Ca₁₀(PO₄)6(OH)₂) is one of the most attractive materials for bone implants due to its compositional and biological similarity to native tissues. Bone is an inorganic–bioorganic composite material consisting mainly of collagen proteins and HAp, and its properties depend intimately on its nano-scale structures.

Polyoxymethylene (POM) shows an ultra high modulus, a high-impact strength, stiffness, resiliency, toughness, low friction coefficient; low gas and vapor permeability; exceptional dimensional stability and dielectric properties; high fatigue strength and good retention of properties at elevated temperature [2]. In the joint replacement area, different POM implants like artificial fingers and shoulder joints are well-known products.

In this work preparation of POM/nanohydroxyapatite composites by melt processing (extrusion, injection moulding) is presented; the influence of the processing conditions on the thermal properties of nanocomposite materials that can be applied in biomedical area is discussed.