[2-[4-(dihexylamino)-2-methylbenzylidene]benzo[b]thien-3(2H)-ylidene]malononitrile S,S-dioxide

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

Study period:

January 22th to February 16th, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

adopted 27 July 1995

GLP compliance:

yes

Type of method:

differential scanning calorimetry

Remarks:

and capillary method

Melting / freezing pt.:

ca. 140 °C

Atm. press.:

1 atm

Decomposition:

yes

Decomp. temp.:

200 - 240 °C

DSC analysis

During the heating up phase, endothermic signal was recorded in the temperature at ca 136 °C, which can be associated to the melting of the substance. Then, an exothermic reaction occurred between ca 200 and 240 °C, which was associated to decomposition of the substance (energy release of ca -210 and -300 °C).

Replicate	Test item Energy (J/g)	Onset Temperature (°C)	Mean onset (°C)	Mean onset (°C)	Peak (°C)	Endset Temperature (°C)
Endothermic (replication 1)	55.10	136.26	136.42	0.17	137.99	139.72
Endothermic (replication 2)	62.38	136.58			138.51	140.16
Exothermic (replication 1)	-216.49	218.85	218.82	0.02	229.10	237.65
Exothermic (replication 2)	-292.45	218.78			229.39	238.05

Appearance of the test item

Replication No.	Appearance of the Test Item at the start	Initial Weight of the Test Item, (mg)	Residue (mg (%))
R1	Blue powder	1.9	1.1 (58 %)
R2	Blue powder	1.9	1.1 (58 %)

Capillary test

The test item melts at 139.8 °C

Conclusions:

The test item undergoes to melt at ca 140 °C, followed by decomposition between ca 200 and 240 °C.

Executive summary:

The thermal behaviour of the substance was investigated in accordance with the OECD guideline 102. For the differential scanning calorimetry experiment, the test item was weighed and placed into the crucible and the test was run with a closed crucible. The prepared capsule was inserted into the DSC apparatus and heated from room temperature up to 500 °C at a constant heating rate of 10 K/min. Before and after the test, the weight of the sample was determined. The measurements were performed under inert atmosphere. The experiment was performed in duplicate.

In order to confirm the DSC outcomes, an additional measurement with capillary method was performed in the temperature range of ca 25 – 250 °C. The experiment was carried out in triplicates.

During the DSC analysis heating up phase, endothermic signal was recorded at the temperature of approx. 136 °C, which can be associated to the melting of the substance. Then, an exothermic reaction occurred between ca 200 and 240 °C, which was associated to decomposition of the substance (energy release of ca -210 and -300 °C). Theexperiment conducted by capillary method confirmed the DSC outcomes since the substance melting point was recorded at ca 139.8 °C

Conclusion

The test item undergoes to melt at ca 140 °C, followed by decomposition between ca 200 and 240 °C.

Description of key information

The test item undergoes to melt at ca 140 °C, followed by decomposition between ca 200 and 240 °C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

140 °C

Additional information

OECD 102/113 - differential scanning calorimetry and capillary method