Typology of the gliding waxes in cross-country skiing: Comparison between classifications based on the chemical composition and those based on the physical and physicochemical properties

摘要

The aim of this study was to compare the classifications of cross-country skiing gliding waxes based on their chemical composition and those based on the physical and physicochemical properties. Fifty commercial gliding waxes were analysed by gas chromatography to describe the alkanes, perfluorocarbons and perfluoroalkanes distributions and by ionic chromatography to define the fluorine elemental content. The physical and physicochemical properties of the studied waxes were measured by penetration tests at four different temperatures and by the wetting tests in static and dynamic modes. Principal Components Analysis was performed as a function of both the chemical composition descriptors and the physical and physicochemical characterisation results in order to identify the waxes typology. The classification based on the chemical composition showed that three groups could be defined: (1) long alkane waxes corresponding to the waxes recommended for the "cold" snow, (2) intermediate alkane waxes ("intermediate" snow) and (3) short alkane waxes ("warm" snow). The classification based on the physical and physicochemical properties pointed out that the waxes for the "cold" snow were the hardest waxes and the waxes for the "warm" snow, the softest ones. Moreover this classification suggested that the physicochemical properties were not linearly correlated with the fluorine additives content. The comparison between both typologies underlined that the waxes composed of long alkanes were the hardest ones while those of short alkanes were the softest ones as well as that the increase of waxes water-repellence was limited despite the increase in the fluorine based additives content. The main result of this study was that the strategy in wax development by the various manufacturers follows the same general trend in relation with the alkane composition but a fine analysis pointed out that each gliding wax manufacturer provides specific formulation in the case of the waxes containing fluorine based additives.