Phenylphosphonic acid

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 October 2017 to 26 October 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Test material

Test material information

Constituent 1

Reference substance name:

Phenylphosphonic acid

EC Number:

216-388-1

EC Name:

Phenylphosphonic acid

Cas Number:

1571-33-1

Molecular formula:

C6H7O3P

IUPAC Name:

phenylphosphonic acid

Test material form:

solid: particulate/powder

Details on test material:

Lot number LKF6065

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sponsor and LKF6065
- Expiration date of the lot/batch: 09 December 2017
- Purity test date: 21 October 2016

Results and discussion

Melting / freezing point

Key result

Melting / freezing pt.:

164.8 °C

Atm. press.:

ca. 1 atm

Any other information on results incl. tables

Preliminary test

The TGA curve of the test item is shown in Figure 1. Starting at 300°C, the weight of the sample decreased significantly. At 385°C, the sample weight had decreased by 25%. After the experiment, an off white brown molten residue remained in the sample container (original colour: white). The change of the colour indicated reaction and/or decomposition of the test item

Main study

The DSC curve obtained with Experiment 1 is shown in Figure 2. An endothermic peak was observed between 150°C and 200°C. The extrapolated onset temperature of the peak was 164.917°C. The endothermic effect was most likely obtained due to melting of the test item. From 250°C an exothermic effect was observed. The exothermic effect was probably obtained due to reaction and/or decomposition of the test item. After the experiment, an off white brown molten residue remained in the sample container (original colour: white). Based on this visual observation, it was found that the test item had molten and the change of the colour demonstrated reaction and/or decomposition of the test item. In order to investigate the melting peak, Experiment 2 was stopped directly after the melting peak. Figure 3 shows the DSC curve obtained. The extrapolated onset temperature was 164.767°C. After the experiment, a white molten residue remained in the sample container. It demonstrated that melting was the reason for the endothermic effect. The melting temperature was determined as the mean melting temperature of Experiment 1 (164.917°C) and Experiment 2 (164.767°C).

Applicant's summary and conclusion

Conclusions:

The melting temperature of Phenyl Phosphonic Acid was determined by DSC.
The melting temperature was determined as the mean melting temperature of Experiment 1 (164.917°C) and Experiment 2 (164.767°C).
The melting temperature of the test item was 164.8°C (438.0K).