Tribological Properties of the Lubricant Released by Temperature-Sensitive Hydrogel

To improve the lubrication performance of artificial joint and to prolong its service life, temperature-sensitive hydrogel is taken as a carrier for releasing lubricants in artificial joint, and the tribological property of the released solution is investigated. The temperature-sensitive hydrogel of polycaprolactone-polyethylene glycol-polycaprolactone (PCEC) copolymer is synthesized by ring-opening polymerization method, and it can undergo the sol-gel transition at simulative body temperature. The release behavior of chitosan (CS)/BSA (bovine serum albumin) mixture carried by temperature-sensitive hydrogel is investigated by Bradford method in vitro. The tribological property of the release solution is measured by friction and wear tests. The concentration of BSA in the release solution is about 1% of the concentration of BSA before release. The friction coefficient of the release solution is about 25% of saline, distilled water or the simulation of body fluids. For Al₂O₃ ceramic ball and Co-Cr-Mo disc pair, the wear rate with the release solution is about 73% lower than that of the saline solution, about 50% lower than the distilled water and about 20% lower than the simulated body fluid.