聚乙烯醇/纳米羟基磷灰石复合水凝胶的接触变形与启动摩擦特性研究

Contact Deformation and Friction Performance of Start-up for PVA/HA Composite Hydrogel

选用高分子聚乙烯醇(PVA)和纳米羟基磷灰石(HA)为原料,采用反复冷冻-融化法制备PVA/HA复合水凝胶,在超高精度三维轮廓仪、光学显微镜和S-3000N型扫描电子显微镜上观察PVA/HA复合水凝胶的微观组织形貌,用精密位移传感器对PVA/HA复合水凝胶的接触变形特性进行测量,采用UMT-II型微摩擦磨损试验机评价PVA/HA复合水凝胶的启动摩擦特性.结果表明:PVA/HA复合水凝胶与天然骨组织具有相似的交联网状微观结构,表现出良好的黏弹性;PVA/HA复合水凝胶在滑动过程中的法向位移变化所对应的时间以及启动摩擦系数与接触时间呈现出先减小而后增大的趋势,在相同接触时间下,天然软骨的启动摩擦系数及其对应的滑行时间均比PVA/HA复合水凝胶小;而PVA/HA复合水凝胶的启动摩擦系数与滑动速率无明显的关联性;试样之间法向位移的转折点及其所对应的滑行时间均随滑动速率的增大而减小,这与天然软骨的试验结果基本一致.

Polyvinyl Alcohol-hydrogel/Hydroxylapatite （PVA/HA） freezing-thawing method using the raw materials of macromolecular HA composite hydrogel were observed under the optical microscope composite hydrogel was prepared by reiterative PVA and HA. The microscopic maps of PVA/ and the Micro XAMTM high-accuracy profilome- ter. PVA/HA composite hydrogel was measured using high-resolution displacement sensor. Th tic of start-up tests on PVA/HA composite hydrogel were performed on UMT-II Micro-tribom posite hydrogel took on the cross linkage and netlike construction, which was similar to that of cartilages e friction characteris- eter. PVA/HA com- bovine knee articular and it showed good viscoelasticity. The starting time corresponded to the variation of normal and the friction coefficient of start-up of PVA/HA composite hydrogel came larger with increasing of contact time. At the same contact time displacement was smaller at the initial phase, then they be- , the friction coefficient of start-up and its cor- responding sliding time for bovine knee articular cartilages were little than PVA/HA composite hydrogel. However, the initial friction coefficient of PVA/HA composite hydrogel was independent on the sliding speed. The maximal displacement and its corresponding sliding time were inversely proportional to the sliding speed, which was similar to that of bovine knee articular cartilages.