Butylated hydroxyanisole
Inactive ingredient (antioxidant)
Measuring cell: DSC820
Pan: Aluminum 40 µl, hermetically sealed
Sample preparation: As received (1) or crystals ground in a mortar (2)
DSC measurement: Heating from 30 °C to 70 °C at 2.5 K/min
Atmosphere: Nitrogen, 50 cm3/min
The two curves show the effects that sample preparation can have on the results. In both cases, two melting peaks can be observed that differ noticeably in temperature range and in the heats of fusion. The explanation lies in the polymorphic behavior of butylated hydroxyanisole. The two peaks correspond to the possible crystal modifications.
Onset temperature determination and integration of the melting peak of the DSC curve.
Sample preparation | Onset 1, °C | ΔH, J/g | Onset 2, °C | ΔH, J/g |
---|---|---|---|---|
as recieved | 59.3 | 78.2 | 63.3 | 27.6 |
ground in a mortar | 55.1 | 96.8 | 61.7 | 1.7 |
A difference in sample preparation (especially mechanical treatment) can lead to different results. This is particularly the case with substances that exhibit polymorphism.
Sample Preparation, Butylated Hydroxyanisole | Thermal Analysis Application No. HB841 | Application published in METTLER TOLEDO TA Application Handbook Pharmaceuticals