PVA-Silk复合水凝胶的启动摩擦性能研究

Research on the Friction Properties of Start-up for PVA-Silk Composite Hydrogel

选用高分子聚乙烯醇(PVA)和脱胶后的蚕丝(Silk)为原料,采用反复冷冻-融化法制备PVA-Silk复合水凝胶.在光学显微镜上观察PVA-Silk复合水凝胶的微观形貌,在UMT-Ⅱ型微摩擦试验机上对PVA-Silk复合水凝胶开展往复式摩擦实验,研究接触时间、滑动速率及冷冻-融化次数对复合水凝胶的启动摩擦性能的影响.结果表明,随反复冷冻-融化次数的增加,PVA-Silk复合水凝胶的交联度增大,结晶度提高,其弹性模量增大,最大法向压缩变形量减小,且其基本恢复变形所需的时间减小;PVA-Silk复合水凝胶在滑动过程中的法向位移量和最大摩擦系数随接触时间的延长而增大,随反复冷冻-融化次数的增加而减少;但最大摩擦系数与滑动速率无明显的相关联性.

The PVA-Silk composite hydrogel was prepared by a reiterative freezing-thawing method using the raw materials of macromolecular polyvinyl alcohol （PVA） and deglued silk. The morphologies of PVA-Silk Composite hydrogel were observed with the optical microscope. The reciprocating sliding tests on PVA-Silk composite hydrogel were performed on the UMT-2 Micro-tribometer to study the effects of contact time, sliding speed and freezing-thawing cycles on friction properties of start-up. The results show that the reiterative freezing-thawing im- proved the degree of cross-linkage and crystallinity for the PVA-Silk composite hydrogel. With the increasing of reiterative freezing-thawing cycles, the elastic modulus increased, the maximal compressed deformation decreased and the period to resume compressed deformation de- creased. The normal displacement and the maximal friction coefficient of PVA-Silk composite hydrogel increased with the increasing of contact time, and decreased with the increasing of the freezing-thawing cycles. The maximal friction coefficient was not correlative with the sliding speed.