Betaine

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

other: Handbook value

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Principles of method if other than guideline:

The melting point of the test substance was reported in an accepted handbook.

GLP compliance:

no

Remarks:

handbook value

Type of method:

other: handbook value

Melting / freezing pt.:

566 K

Conclusions:

The melting point of the substance is 566 K.

Executive summary:

The melting point of the substance is 566 K.

Description of key information

The melting point value was obtained from a generally accepted Handbook of Chemistry and Physics 89th edition (2008). The decomposition temperature of the substance was obtained from generally accepted peer-reviewed scientific papers presented by Viertorinne et al. (1999) and Suuronen et al. (2002).

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

566 K

Additional information

This substance melts at a temperature between 566 to 570 K. The melting point was determined by thermal analysis using Differential Scanning Calorimetry. According to Viertorinne et al. (1999), decomposition of the substance begins at the same time as melting. The total energy of the melting and decomposition was measured to be 74(4) kJ/mol at the 2 K/min heating rate in a nitrogen atmosphere.

The thermochemical behaviour of the substance was studied by Suuronen et al. (2002). As concluded in this study, the tested substance decomposed in the temperature range of 525 -596 K. The residual carbon burnt in the air forming CO₂ up to a temperature of 843 K. Esterification was one of the most important pyrolytic processes of this substance. Trimethylamine, CO₂ and glycine esters were the main degradation products in pyrolysis. Degradation compounds were determined by using TG-FTIR.