Amorphous condensation products of orthophosphoric acid and sodium carbonate (3-6 : 1)

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7220 (Boiling Point / Boiling Range)

Version / remarks:

This guideline also applies to the result

Type of method:

differential scanning calorimetry

Specific details on test material used for the study:

During inquiry (inquiry number: 06-2120767575-41-0000 ) the name was changed from „Reaction mass of metaphosphoric acid and trisodium trimetaphosphate” to “Amorphous condensation products of orthophosphoric acid and sodium carbonate (3-6 : 1)“.

Boiling pt.:

> 500 °C

Atm. press.:

1 013 hPa

Melting and Boiling Point via DSC

The thermograms of the DSC runs with open aluminium crucibles PN12841 and PN12842 are shown in Figure 1 and Figure 2 and the thermograms of the DSC runs with open glass crucibles PN12958 and PN12969 in Figure 3 and Figure 4.

Table 1:  Results of the DSC-measurements

 

No.	Crucible material	Sample weight / mg	Onset of Effect I °C	Range of effect I °C	Remark
PN12841	Aluminium	14.77	99.88 ---	100 - 160 (endothermic) 290 - 500 (exothermic)	Figure 1
PN12842	Aluminium	22.72	101.30 ---	100 - 160 (endothermic) 250 - 500 (exothermic)	Figure 2
PN12958	Glass	20.57	100.27	100 - 200 (endothermic)	Figure 3
PN12969	Glass	19.00	104.02	100 - 200 (endothermic)	Figure 4

During the heating phase the test item showed in all measurements an endothermic effect in the temperature range of 100 - 200 °C, which cannot be clearly assigned to the melting of the test item. For an optical verification of the endothermic effect a measurement with capillary method was carried out. In this measurement, the endothermic effect in the temperature range of 100 - 200 °C could be verified as a melting of the test item. Since the test item showed a broad melting range, the onset temperatures of the DSC measurements cannot be used for evaluation.

In the measurements with open aluminium crucibles an exothermic effect could be observed in the temperature range of 250 - 500 °C with a mean decomposition energy of approx. -270 J/g. Due to the fact that this effect was not observed in the measurements with open glass crucibles, it can be stated that this effect was caused by a reaction of the test item with aluminium. The DSC measurements in open glass crucibles showed no further thermal effects up to the maximum test temperature of 500 °C. Due to this result, the test item has no boiling point up to a temperature of 500 °C.

 

Measurements by the capillary method

To verify the results of the DSC measurements, an additional measurement with the capillary method (Apparatus: Stuart Melting Point SMP30) was performed in the temperature range of 50 - 250 °C with a heating rate of 10 K/min. The observations during the test with the capillary method are summarized in Table 2.

 

Table 2:    Observations during the test with the capillary method (Heating rate: 10 K/min)

 

Temperature	Observation	Temperature	Observation
Start (50°C)	White,glasslikepowder	143 °C	Test item almost clear andc olourless
75 °C	White,glasslikepowder	150 °C	Clear,colourless viscousliquid
100 °C	White,glasslikepowder	175 °C	Clear,colourless viscousliquid that seems toliquefy
110 °C	Particles slowly baking to gether	200 °C	Clear,colourless liquid
120 °C	Appearance slowly changes from white to clear andc olourless	225 °C	Clear,colourless liquid
135 °C	Sintering	end (250 °C)	Clear,colourless liquid

Accord ing to the observations during the test with the capillary method, the endothermic effect in the temperature range of 100 - 200°C in the DSC measurements can be assigned to the melting of the test item. The test item has a melting range from 135 - 150 °C.

Conclusions:

The test item meta-phosphoric acid has no boiling point up to a temperature of 500 °C at atmospheric pressure (1013 hPa) as determined by differential scanning calorimetry according to Regulation EC No. 440/2008 Method A.2 ., OECD Test Guideline 103 (1995) and EPA OCSPP 830.7220 (1996).

Executive summary:

The test item meta-phosphoric acid has no boiling point up to a temperature of 500 °C at atmospheric pressure (1013 hPa) as determined by differential scanning calorimetry according to Regulation EC No. 440/2008 Method A.2 ., OECD Test Guideline 103 (1995) and EPA OCSPP 830.7220 (1996).

Description of key information

The test item Amorphous condensation products of orthophosphoric acid and sodium carbonate (3-6 : 1) has no boiling point up to a temperature of 500 °C at atmospheric pressure (1013 hPa) as determined by differential scanning  calorimetry according to Regulation EC No. 440/2008 Method A.2 ., OECD Test Guideline 103 (1995) and EPA OCSPP 830.7220 (1996).

Key value for chemical safety assessment

Boiling point at 101 325 Pa:

500 °C

Additional information

no boiling point up to a temperature of 500 °C