Performance evaluation of chitosan/hydroxyapatite composite coating on ultrahigh molecular weight polyethylene

The aim of the present study is to evaluate the performance of chitosan/hydroxyapatite (CTS/HA) coatings on ultrahigh molecular weight polyethylene (UHMWPE). We focused on adhesion measurements, micro-hardness indentation, friction and wear tests. Using commercial compounds of medical grade, CTS/HA composite was prepared by a simple mixture using acetic acid as solvent. The CTS/HA solution obtained was used to prepare coatings on UHMWPE substrates by the immersion method. Scanning electronic microscopy (SEM) results showed that the composite coating had flake-like morphology characteristic of chitosan and calcium phosphate powders with a porous structure. The adhesion strength between CTS-HA coating and UHMWPE was approximately 0.15 MPa, according the ASTM D5179 method. The micro-hardness of CTS/HA coating on UHMWPE was evaluated by using a Vickers hardness tester, while friction and wear were studied by a pin-on-disk method in dry conditions.