Reaction mass of divinylbenzene and ethylstyrene

Endpoint summary

Description of key information

The substance various grades of the test substance are pale, straw-coloured liquids with an odour characteristic of aromatic compounds. The melting point for DVB-55 and DVB-HP were both determined to be below -20°C; the melting point of DVB-55 was -45°C. The boiling point of DVB-55 was 195°C. DVB-HP has been determined to polymerise from 418 K at 98.54 kPa. As the test material polymerised prior to boiling, no value for boiling point could be determined for this grade of the reaction mass. The measured density of DVB-55 and DVB-HP reported by different sources was 0.91-0.92 g/mL at 25°C. As there is no significant difference in the density reported for DVB-55 and DVB-HP it can be concluded that the density of DVB-63 is also 0.91 -0.92 g/mL. Vapour pressure of 50.9 Pa at 20°C is from a DVB high purity sample. Different grades of DVB will give slightly different vapour pressure values. The log Kow of the reaction mass of divinylbenzene and ethylstyrene was determined to be 3.80. The HPLC estimation method did not produce chromotographic resolution of the component isomers. However, calculation of log Kow of these components using the structure-fragment method (KOWWIN) indicates similar log Kow values for divinylbenzene (3.80) and ethylstyrene (3.93). The calculation method, as well as reported measured log Kow values, for DVB indicate little difference in log Pow for positional isomers of these substances. The single value of log Kow resulting from the HPLC estimation is therefore regarded to give a suitable representation of the log Kow of the closely related components. Reported measured water solubility values range from 36-52 mg/L for different grades of the reaction mass of divinylbenzene and ethylstyrene. The documented Key Study for DVB-HP, giving a value of 36 mg/L, is considered to be a reliable determination of the water solubility of the reaction mass. The surface tension of a 0.0251 g/L solution of DVB-HP has been determined to be 68.7 mN/m at 20°C. The test material is considered not to be a surface-active material. As no surface-activity has been observed with DVB-HP, no such activity is expected with the other grades of the reaction mass of divinylbenzene and ethylstyrene. The flash point of DVB-55 and DVB-HP are 65.6°C and 69°C, respectively. Auto-ignition temperature of DVB-55 has been determined to be 505°C. Auto-ignition temperature of DVB-HP has been determined to be at least 400°C. DVB-55 is not flammable. The substance does not contain chemically unstable or highly energetic groups like those mentioned in table R.7.1-28 (ECHA Guidance, 2008). Therefore, the substance is determined to be not explosive. The molecular structure of the components of the substance do not contain functional groups known to exhibit oxidising properties (ECHA Guidance Table R.7.1-29, 2008). Examination of the chemical structure of divinylbenzene and ethylstyrene shows that there is no functional group that could dissociate. DVB-55 has a viscosity of 1.0 cp @ 25°C, which is equal to 1 mPa.s @ 25°C. The granulometry endpoint was waived as all grades of the test substance are liquids. Stability in organic solvents endpoint is waived as this is not critical for the test substance.