Reaction product of mixed inorganic base and acid resulting in complex boron, potassium, fluoride and potassium fluoride constituents

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed according to international guidelines

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

adopted 27 July 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

EC 440/2008 of 30 May 2008

Deviations:

no

Principles of method if other than guideline:

In a measurement with differential scanning calorimetry (DSC) a sample of the test item and a reference material (identical crucible without the test item) are subjected to the same controlled temperature program. The difference in the temperatures of the test item and the reference material is recorded and applying a calibration function converted to a heat flow signal. When the sample undergoes a transition involving a change in enthalpy (endothermic on melting), that change is indicated by a departure from the base line of the heat flow record.

Thermogravimetry (TG) is based on continuous recording of mass changes of a sample as a function of temperature (with first derivative curve DTG).

Simultaneous Thermal Analysis (STA) generally refers to the simultaneous application of Thermogravimetry (TG) and Differential scanning calorimetry (DSC) to one and the same sample in a single instrument. The test conditions are perfectly identical for the TG and DSC signals (same atmosphere, gas flow rate, vapor pressure of the sample, heating rate, thermal contact to the sample crucible and sensor, radiation effect, etc.). The analyzability of the signals is improved, since two or more sets of information concerning sample behavior are always simultaneously available (differentiation between phase transformation and decomposition, between addition and condensation reactions, recognition of pyrolysis, oxidation, and combustion reactions, etc.).

GLP compliance:

yes (incl. QA statement)

Remarks:

DIN EN ISO/IEC 17025 certified

Type of method:

other: differential scanning calorimetry (DSC)

Specific details on test material used for the study:

Umicore h80 paste

Melting / freezing pt.:

393 °C

The DSC measurement was combined with a thermogravimetric (TG) measurement. The sample was purged 30 minutes with nitrogen before the start of the measurement (heating ramp). Purging loss (see diagram 1 and 2) must be added to the first step and to the total weight loss. When the measurement was performed up to 1000 °C, the molten residue had crept up the crucible walls, so that the lid was stuck with the crucible rim and the sample holder was contaminated. The heat flow curves show several not exactly reproducible endothermic and exothermic peaks which all correspond to a significant mass loss (multi-stage degradation). Only the endothermic peak with a maximum at 416/414 ° C shows no decrease in weight. Therefore it most probably represents the melting of the already partially degraded test substance at 394/392 °C (extrapolated onset temperature). Upon further heating decomposition is registered.

Conclusions:

Melting temperature is 393 °C

Description of key information

The melting point for this substance is 393 °C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

400 °C