Abstract:Objective To study the effect of preparation parameters on structure and friction properties of PVA hydrogels, which provids an academic foundation for application potentials of PVA hydrogels for cartilage repair. Methods γ-Ray radiation crosslinked PVA hydrogels were prepared by freezing-thawing method combined with irradiation technique, microstructure and friction properties when sliding against nature articular cartilage were studied. Results (1) SEM observation illustrated that PVA hydrogels had a three-dimensional network structure and such structure became denser after irradiation. (2) Water content of PVA hydrogels increased with the increasing of irradiation dose and PVA concentration. (3) Friction properties of PVA hydrogels were performed on a reciprocating pin-on-plate machine sliding against nature articular cartilage. The results showed that at shorter loading times, a high proportion of the load was carried by fluid phase which resulted in a lower friction coefficient. As the time gone, more fluid was squeezed away from the contact zone, and the load was transferred to the solid phase of PVA hydrogels, which increased friction coefficient and reached a stable level. Lubrication mechanism transferred from biphasic lubrication to mixed lubrication. Friction coefficients of PVA hydrogels increased with the increasing of irradiation dose and PVA concentration.