紫外分光法によるポリビニルアルコールゲルの摩耗解析

抄録

Hydrogel is a 3D polymer network swollen by water, and it is expected as biomaterials like artificial cartilage. It is important to research on mechanical properties of hydrogel for its application, but difficult to evaluate its wear because the change in surface morphology, mass, and volume by wear is not retained due to swelling after the sliding test. In this report, we focused on the released polymer from the hydrogel by wear into the lubricant and quantitate the amount of polymer by UV spectrometry or TOC measurement. We prepared Poly(vinyl alcohol) (PVA) hydrogel and conducted its wear test using the strain-controlled rheometer. Then, UV spectrometry was performed for the lubricant to determine the quantity of PVA polymer using the absorbance at 280 nm that corresponds to the absorption of the carbonyl group at the unsaponified part of PVA. Also, TOC measurement was demonstrated for the lubricant with very low PVA content. First, we confirmed that we could determine the concentration of PVA in the lubricant using the calibration curve of PVA aq. solutions acquired from UV spectrometry. As a result of sliding of PVA gel against glass substrates with various surface roughness, specific wear rate depended on the size of surface roughness. In addition, the wear rate of the gel with surface concave patterns was lower than that of the gels with flat surface. This is because the surface holes of concave hydrogel reduce the contact area and promote the lubrication by trapped water.