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Physical & Chemical properties

Endpoint summary

Administrative data

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The melting point of this substance proved difficult to measure. Testing using an Automated Mettler Toledo MP70 Melting Point System gave inconsistent results with the values from the machine not matching with the visual process of melting. The machine did suggest that the melting point lay in the range 32 -78C. Measurements using the Siwiloboff method produced more consistent results but suggested that melting occurred over the range 32 -72C. There was also some evidence of decomposition (discoloration) occuring. Measurements using a differential scanning calorimeter suggested that there are two transitions of state occuring, one at 32C and a second at 73C, although the lower transition could not be reproduced consistently. It can be concluded that the substance will be a solid below 32C and will be a liquid above 78C but the phase state in between is unclear. For this reason, a single value for the melting point is not reported. The boiling point as determined by the Siwiloboff method was 118C. However, this does seem quite low and may be a reflection of the water of crystallisation content rather than the underlying boiling point of the anhydrous material. This determination was also inconsistent with the DSC data from the melting point determination which did not show evidence of a phase transition or endothermic event around this temperature. The test item is believed to decompose above 200°C.

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