Quantifying Residual Coning Oils in Quantitative Viscose Content Determination
Unextracted coning oils add false mass to insoluble fiber fractions during quantitative chemical dissolution, distorting declared viscose blend percentages.
Reagent Passivation Barrier
Chemical Retardant
Physical or chemical layer that forms on the surface of a material prevents further reaction with the surrounding environment. During the quantitative analysis of fiber blends, a reagent passivation barrier sometimes develops on the insoluble fiber, shielding it from the solvent. This layer stops the dissolution process before it is complete.
It is a surface phenomenon that occurs at the interface between the solid and liquid phases.
Reaction Surface
Accessibility of the polymer chains to the chemical reagent is necessary for a successful separation. If a reagent passivation barrier forms, the solvent cannot penetrate the inner core of the fiber. This leads to an overestimation of the weight of the insoluble component.
Solubility Limit
Concentration of the dissolved material in the bath can reach a point where the reagent is no longer effective. When a reagent passivation barrier occurs, it is often because the reaction products have accumulated at the interface between the liquid and the solid. Stirring the solution or increasing the volume of the reagent can help.
Analytical Accuracy
Errors in the reported fiber composition can lead to the mislabeling of garments and potential legal issues. A reagent passivation barrier is a known problem in the analysis of wool and polyester blends. Technicians must ensure that the sample is finely divided to maximize the surface area for the reaction.