Objective To investigate the rheological properties of ointment base white vaseline.Methods The rheological curves,yield stress,thixotropy,linear viscoelasticity and creep recovery of white vaseline were studied under steady shear mode and oscillatory shear mode by Kinexus rotational rheometer.Results The rheological curves were measured using PU20 frosted fixture.The gap was 0.5 mm,the temperature was set at(32±0.1)℃,then the RSDs of shear viscosity test results at different shear rates including 1,10 and 100 s-1 were 14.59％,4.64％and 3.42％,respectively.In the range of 1-100 s-1,the viscosity decreased with the increase of shear rate.The viscoelasticity was measured using PU20 frosted fixture.The gap was 0.5 mm,the temperature was set at(25±0.1)℃.When the shear rate was 10 Hz,the RSDs of G'and G"were 10.89％and 9.46％,respectively.When the shear strain ranged from 0.01％to 0.2％,white vaseline showed linear viscoelastic characteristics,and the elastic modulus was always slightly higher than the viscous modulus.Conclusion The method is simple,accurate and reproducible.White vaseline has a rheological behavior of shear thinning and is a non-Newtonian fluid.Under the measure conditions,white vaseline tends to have solid-like viscoelastic characteristics,and has strong thixotropy and creep recovery ability.
关键词
白凡士林/旋转流变仪/稳态剪切/振荡剪切/流变学性质
Key words
white vaseline/rheometer/steady shear/oscillatory shear/rheological property
维普
万方数据