Abstract
Poly (vinyl alcohol) (PVA) hydrogel is the candidate material for artificial cartilage. PVA hydrogels prepared by hybrid method of freeze-thawing (FT) and cast-drying (CD) method (PVA-hybrid gel) were developed, and lubrication property of PVA-hybrid gel was evaluated. Sliding pairs of an ellipsoidal PVA hydrogel and a flat glass plate were tested in reciprocating friction test. PVA-hybrid gels were prepared by temperature (T) and humidity (H) controlled drying process. Friction of PVA-hybrid gel prepared by drying process at T of 8°C and H of 80%RH gradually increased. PVA-hybrid gel prepared by drying process at T of 8°C and H of 50%RH showed low friction coefficient of 0.013 but it gradually increased with increase of sliding distance and surface damage was progressed. When the additional drying process at T of 20°C and H of 40%RH after the drying process at T of 8°C and H of 50%RH was provided, PVA-hybrid gel showed extremely low friction coefficient such as 0.006 and wear of this hybrid gel was slight. The additional drying process contributes to obtaining the surface layer of PVA-hybrid gel with low friction and low wear.
