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Physical & Chemical properties

Melting point / freezing point

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Description of key information

Coco AAPB: fraction C8/C18: m.p.: 208°C; fraction C8/C10: m.p.: 55-60°C; fraction C12/C14: m.p.: 69-187°C
C8-18 AAPB: not identifyable due to decomposition of the test substance in the range between 208 and 280°C
C12 AAPB: not identifyable due to decomposition of the test substance in the range between 60 and 260°C

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Additional information

In studies conducted according to OECD Guideline 102, the melting points of C8 -18 AAPB and C12 AAPB were investigated using differential scanning calorimetry (DSC). Melting points were not identifyable due to decomposition at temperature ranging from 208 to 280 (C8 -18 AAPB) and 60 and 260°C (C12 AAPB). Based on these results it can be assumed that a weak chemical bond is present in the molecule which is unstable towards elevated temperatures. All AAPBs are similar in structure, contain all the same zwitterionic structure. They differ, however, by their carbon chain length distribution and the degree of unsaturation (<=20%) in the fatty acid moiety. The content of minor constituents in all products are comparable and differ to an irrelevant amount. Based on the available data, it can be assumed that chain length distribution and degree of unsaturation of the fatty acid chain have no or at the most a minor impact on this endpoint.

The melting points of the different fractions of Coco AAPB determined via the capillary method are judged as not reliable as the method does not distinguish between a real melting process and a reaction/decomposition process and as comparable temperatures were found as decompostion temperature in the DSC measurements.