聚氧化乙烯水溶液粘度的测定

测定了不同分子量聚氧化乙烯(PEO)在水溶液中的粘度，发现在低浓度区高分子溶液比浓粘度出现负偏离。用高分子溶液流过时间对浓度作图的外推值t0^*重新计算相对粘度，则高分子溶液比浓粘度与浓度之间满足线性关系。不同分子量PEO水溶液流过时间对浓度作图的外推值t0^*是完全一致的。利用纯溶剂在粘度计中流过时间的改变确定了高分子在毛细管管壁上吸附层的厚度，发现PEO在毛细管管壁上吸附层厚度与分子量无关。

Viscosity Determination of Poly(ethylene oxide) in Aqueous Solutions

The viscosity of Poly (ethylene oxide)(PEO) in aqueous solutions was determined by using the Ubbelohde type viscometer with the capillary diameter of 0 38 mm. It has been found that there existed a negative deviation from linear relationship at lower concentrations in the plot of the reduced viscosity versus concentration. If t * 0, obtained by extrapolating to zero concentration according to the relationship between the flow time of polymer solution and concentration of polymer in solution, was employed to determine the viscosity of polymer solution, the linear realtionship between the reduced viscosity and concentration was observed to exist even at lower concentrations. The values of t * 0 of PEO with different molecular weights were just the same. By recording the increase of the flow time of the pure solvent detected by the specially designed experimental procedure, the thickness of the adsorbed polymer layers was determined.It was noted that the molecular weight of PEO had no influence on the thickness of the adsorbed polymer layers on the viscometer capillary walls.