Quaternary ammonium compounds, C12-14-alkyl[(ethylphenyl)methyl]dimethyl, chlorides

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Remarks:

Melting point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From November 2001 to January 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Specific details on test material used for the study:

Lot no: MRT-2518-038
Identity: C12-14 ADEBAC
Purity: 68 % C12-alkyl compound, 32 % C14-alkyl compound
Appearance: White solid
Storage: Room temperature, desiccated

Key result

Atm. press.:

ca. 1 atm

Decomposition:

yes

Decomp. temp.:

> 130 °C

Remarks on result:

not determinable

Remarks:

The test substance melted with decomposition between temperatures of approximately 130ºC and 170ºC.

Table 1: DSC analysis of Ethyl Benzyl Quat

Run	Temperature range (ºC)	Heating (C/min)	Endotherm temperatures			Observations
			Extrapolated onset	Peak	End
1	20 to 400	10	108.4 133.4 190.4	111.4 148.4 208.4	119.4 168.4 326.4	Endotherm. Small endotherm. Complex large endotherm Sample re-run after cooling (run 2).
2	20 to 400	10	-	-	-	No sample remained in the crucible after this test. Given the absence of thermal features, it is considered that no sample remained after run 1.
3	20to 150	5	109.2	111.2	117.7	Endotherm. Start of endotherm at end of DSC run from ca. 136ºC. Sample re-run after cooling (run 4).
4	20 to 150	5	-	-	-	No features at ca. 110ºCsuggesting chemical change, possibly removal of water. Start of endotherm at end of DSC run from ca. 132ºC.
5	20 to 120	5	104.2	107.2	111.2	Endotherm. Sample re-run after cooling (run 6).
6	20 to 400	5	104.2	107.2	115.2	Endotherm, the presence of which suggests that not all water was removed during run 5, when the temperature was raised to only 120ºC. Baseline drifts off-scale after this endotherm, therefore cannot confirm temperatures of the thermal features beyond this point. A black charred residue remained at the end of the test.
7	20 to 200	5	Visual observations only (viewed from open crucible)			When inspected at 20, 105, 110, 115, 120, 130 and 140ºC, the sample was observed to be in the form of a soft white solid. At 150ºC, the sample was observed to be in a molten state, whilst at 160ºCand 170ºC, decomposition had clearly occurred as a brown

Conclusions:

Under study conditions, melting point could not be determined due to decomposition of test substance between temperatures of approximately 130 and 170ºC

Executive summary:

A study was conducted to determine the melting point of the test substance, C12 -14 ADEBAC (active not specified), according to the OECD Guideline 102 and EU Method A.1, in compliance with GLP. The experiement was performed using Differential Scanning Calorimeter (DSC) appratus. The endotherm at approximately 110ºC was shown not to persist on repeated temperature cycling (Compare runs 3 and 4), suggesting that a chemical change, possibly removal of water from the test substance, had occurred. The same effect was not observed between runs 5 and 6, but, as the temperature was raised to only 120ºC during run 5, it is considered that the temperature was not high enough to remove all of the water. The small endotherm, did onset approximately 130 - 140ºC, ended approximately 170ºC, which merged with a complex larger endotherm, was consistent with the melting temperature of the test substance, as supported by visual observation in the boiling temperature test. The complex endotherm with which the melting endotherm merges was indicative of decomposition, which was supported by the observed darkening of the test substance from approximately 140ºC, as observed during the boiling temperature test. The onset of decomposition at this temperature was not discernible when viewed in the open crucible in run 7, although decomposition was clearly apparent at 160ºC. The results indicated that the test substance did not have a distinct melting temperature, but melted with decomposition between temperatures of approximately 130ºC and 170ºC. Under study conditions, the melting point could not be determined due to decomposition of test substance at 130-170ºC (Sydney 2002).

Description of key information

Melting point of the test substance was determined using Differential Scanning Calorimeter (DSC) apparatus, according to the OECD Guideline 102 and EU Method A.1 (Sydney, 2002).

Additional information

no distinct melting point as substance decomposed with melting between 130-170°C