Reaction mass of m,alpha-dimethylstyrene and p,alpha-dimethylstyrene

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 31 July 2018 to 13 August 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 31 July 2018 to 13 August 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Version / remarks:

2016

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7220 (Boiling Point / Boiling Range)

Version / remarks:

1996

Deviations:

no

GLP compliance:

yes

Type of method:

differential scanning calorimetry

Key result

Boiling pt.:

187.3 °C

Atm. press.:

>= 1 006 - <= 1 010 hPa

see IUCLID 4.2 melting point

Conclusions:

The boiling temperature of the substance was determined to be 187.3°C (at 1008 ± 2 hPa).

Executive summary:

See IUCLID 4.2 melting point

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

2016

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

1995

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Version / remarks:

1998

Deviations:

no

Principles of method if other than guideline:

No melting/freezing point could be determined by DSC. Therefore an additional experiment was performed in which the consistency of the substance was determined by visual observation after storage in freezers at ca. -20°C and at ca. -80°C. The additional experiment is not a guideline study but was described in sufficient detail in the study report.

GLP compliance:

yes

Type of method:

other: 'differential scanning calorimetry' and 'storage in freezer'

Test material

Test material information

Constituent 1

Reference substance name:

m,α-dimethylstyrene

EC Number:

214-394-9

EC Name:

m,α-dimethylstyrene

Cas Number:

1124-20-5

Molecular formula:

C10H12

IUPAC Name:

1-isopropenyl-3-methylbenzene

Constituent 2

Reference substance name:

p,α-dimethylstyrene

EC Number:

214-795-9

EC Name:

p,α-dimethylstyrene

Cas Number:

1195-32-0

Molecular formula:

C10H12

IUPAC Name:

1-isopropenyl-4-methylbenzene

Test material form:

liquid

Details on test material:

Appearance: Clear colourless liquid
Storage conditions: At room temperature

Results and discussion

Melting / freezing point

Key result

Melting / freezing pt.:

< -80 °C

Any other information on results incl. tables

DSC EXPERIMENT 1

N crystallization effect was observed during cooling to -90°C. During heating an endothermic effect was observed between 150°C and 200°C (extrapolated onset temperature: 187.317°C). After the experiment it was observed that the test item had evaporated from the sample container.  DSC curve: see illustration below.

DSC EXPERIMENT 2

In order to investigate the endothermic effect, a higher heating rate of 50°C/minute was used. The extrapolated onset temperature of the endothermic effect was 188.224°C. The endothermic effect had not shifted significantly to higher temperatures. It demonstrated that boiling of the test item caused the endothermic effect. After the experiment it was observed that the test item had evaporated from the sample container. Since a higher heating rate was used, the extrapolated onset temperature was not used in the calculation of the boiling point.

DSC EXPERIMENT 3

Similar results as in Experiment 1 were obtained. The extrapolated onset of the boiling effect was 187.343°C.

STORAGE IN FREEZER

After storage in a freezer (-24.1 ± 0.8°C) for 20 hours, the test item was observed to be a liquid.

After storage in freezer (-83.6 ± 1.6°C) for 20 hours, the test item was observed to be a liquid.

DATA HANDLING

Boiling temperature: the mean extrapolated onset temperature of DSC Experiment 1 (187.317°C) and DSC Experiment 3 (187.343°C).

Applicant's summary and conclusion

Conclusions:

The substance has no melting/freezing point at temperatures down to -80°C.

Executive summary:

Differential Scanning Calorimetry was performed to determine the melting and boiling temperature. The experiments were based on EC A.1, OECD 102 and OPPTS 830.7200 (melting temperature) and on EC A.2, OECD TG 103 and OPPTS 830.722 (boiling temperature). There was no DSC effect due to melting/freezing of the liquid substance between 25°C and -90°C. The boiling temperature was determined from the extrapolated onset temperature of the endothermic boiling effect: 187.3°C at 1008 ± 2 hPa (mean of duplicate experiments).

After storage in freezers (ca -20°C and ca -80°C), the substance was visually observed to be a liquid. From this it was concluded that the substance has no melting/freezing point at temperatures down to -80°C.