[1,1'-Biphenyl]-2,2'-diol, 3,3',5,5'-tetramethyl-

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

GLP compliance:

yes (incl. QA statement)

Type of method:

thermal analysis

Test material

Test material information

Constituent 1

Reference substance name:

3,3',5,5'-tetramethyl-[1,1'-biphenyl]-2,2'-diol

EC Number:

607-957-9

Cas Number:

26567-10-2

Molecular formula:

C16 H18 O2

IUPAC Name:

3,3',5,5'-tetramethyl-[1,1'-biphenyl]-2,2'-diol

Results and discussion

Melting / freezing point

Melting / freezing pt.:

137.2 °C

Any other information on results incl. tables

The melting point was determined by differential scanning calorimetry (DSC). In the preliminary DSC screening a melting point of 135.0 °C (onset) was measured. Based on this result, the temperature range to be examined in the main test was set to 90°C – 190°C.

The test was performed with a heat flux differential scanning calorimeter. Details of the DSC experiment are summarized in the table below.

Parameters                            Test 1 / Pre-Test Test 2                                   Test 3

System                            DSC 822               DSC 822                 DSC 822

Start Temp. [°C]                     25                      90                                   90

Rate (heating 1) [K/min]          10                      10                                   10

End Temp. [°C]           400                                     190                 190

Rate (cooling) [°C/min]            ---                                    -10                 -10

End Temp. [°C]                       ---                                  90                  90

Rate (heating 2) [°C/min           ---                                    10                  10

End Temp. [°C]            ---                                    190                  190

Crucible type           aluminium, high                  aluminium, high aluminium, high

Open / Sealed           open   (perforated) sealed                  sealed

Test atmosphere           air                                    air                  air

Air pressure           ambient                  ---                   ---

Amount [mg]           12.26               15.04                   21.4

Mass loss [mg] / [%]           10.59 / 86               0.00 / ---                   0.00 / ---

The solid test item was weighed into an aluminium crucible and was measured against a sealed reference aluminium crucible filled with 16.58 mg aluminium oxide. The sample crucible was sealed at ambient atmosphere (air) and then the test program was started.

For the calculation of the melting point only the values measured in the second heating step were taken into account. The values of the first heating step show a deviation of more than ± 0.5°C which is caused by the fact that the test item powder was not compressed in the measuring crucible. Therefore the contact to the bottom of the aluminium crucible was different resulting in a different heat transfer in the first heating step. Once the material was melted for the first time, the contact to the bottom of the crucible is equivalent for both samples and the found melting points are almost identical. Despite the higher deviation in the first heating step the cyclic measurement shows that the melting reaction is a reversible process.