RESUMEN
Objective To cross-link the porous biological ceramics and PVA hydrogel to form a double layer construction between the artificial cartilage and hard joint, and to analyze its morphologies and mechanical properties. Methods With hydroxyl apatite (HA) as the substrate, the porous hydroxyl apatite biological ceramics with different porosities were prepared by using NH4HCO3 crystal grains as the pore-formed material. The poly vinyl alcohol (PVA) and epoxypropane were used as the primary material and cross-linking agent, respectively. The PVA hydrogel with double layer construction was cross-linked and prepared on the porous biological ceramics surface. The fracture appearances of the test specimen section were characterized. The performances of anti tensile strength and anti-shear strength for PVA hydrogel were analyzed. Results The cross-linked PVA hydrogel could permeate in the biological ceramics substrate, and the union between ceramic substrate and PVA hydrogel performed well. With the porosity of the porous biological ceramics increasing, the tension load and shear load of the PVA hydrogel samples both increased, and with the average porosity of 70%, the samples’ biggest tension load and shear load were 153.61 N and 64.46 N, respectively. But the corresponding tensile strength and shear strength both decreased and with the average porsity of 70%, the samples’ biggest tensile strength and shear strength were 2.12 MPa and 1.13 MPa, respectively. The failure mode of both tension and shear tests for PVA hydrogel samples was due to the crack propagation, and the fracture morphologies showed that obvious cracks and internal defects appeared on the fracture surface, while the source of the crack and the direction of the crack propagation could be observed. Conclusions Considering the compression strength of porous biological ceramics, the permeation effect on the porous biological ceramic substrate with the average porosity of 50% is moderate to be used, which ensures the appropriate shear and tensile strength of PVA hydrogel samples and the compression strength of porous biological ceramic.