Standard Test Method for Measurement of Transition Temperatures of Slack Waxes used in Equine Sports Surfaces by Differential Scanning Calorimetry (DSC)

Importancia y uso:

5.1 DSC is a convenient and rapid method for determining the temperature limits within which a wax undergoes during transitions. The highest temperature transition is a solid-liquid transition associated with complete melting; it can guide the choice of wax binders used in synthetic equine sports surfaces, provide information on the effect of operational track temperatures on binder melting, as well as giving indications of changes in the binder over time. The solid-solid temperature transition is related to the properties of the solid, that is, hardness and blocking temperature, although these slack wax-wax based binders typically contain oil contents greater that 20 % by mass and consequently are not in a hardened state unless subjected to very cold temperatures (well below –17 °C).

Note 2: For a relatively narrow cut petroleum wax, the lowest transition will be a solid-solid transition. A narrow cut wax is one obtained by de-oiling a single petroleum distillate with a maximum range of 49 °CF between its 5 and 95 % vol in accordance with Test Method D1160 boiling points (converted to 760 torr). The DSC method cannot differentiate between solid-liquid and solid-solid transitions. Such information must be predetermined by other techniques. In the case of blends, the lower temperature transition may be envelopes of both solid-liquid and solid-solid transitions.

5.2 Since petroleum wax is a mixture of hydrocarbons with different molecular weights, its transitions occur over a temperature range. This range is one factor that influences the width, expressed in degrees Celsius, of the DSC peaks. The highest temperature transition is a first-order transition. If, for a series of waxes, there is supporting evidence that the highest temperature transition of each wax is the major first-order transition, its relative width should correlate with the relative width of the wax’s molecular weight distribution.

Subcomité:

F08.28

Referida por:

F3588-22

Volúmen:

15.07

Número ICS:

75.140 (Waxes, bituminous materials and other petroleum products)

Palabras clave:

binder, thermal properties; differential scanning calorimetry; petroleum wax; transition temperature;