Synthetic resin, a reaction product of 4,4'-bis(N-maleimido)diphenylmethane with 3-aminobenzoic acid hydrazide

Endpoint summary

Additional information

The test item Compimide 183 is described as a brown re-solidified solid with a specific odour at 20°C and 1013 hPa (visual assessment during tests on physicochemical properties).

The melting point of Compimide 183 was determined in a study performed according to OECD Test Guideline 102 using first a thermogravimetric measurement and subsequently differential scanning calorimetry (DSC). The course of the thermogravimetric curve between 88 and 451°C suggests decomposition of the test item at approx. 160°C and  no sharp endothermic peak indicating a melting point could be observed, thus, Compimide 183 was considered to decompose but exhibits no melting or boiling point during this measurement. However, the DSC curve showed a somewhat flunctuating course at a temperature of approximately 80°C and a glass transition was reported at 35°C. In another study conducted according to OECD test guideline 113 (1981) which was performed in order to measure the thermal stability, a small but sharp endothermic peak was also detected during a DSC measurement at approximately 50 to 60°C. However, in these measurements the test item showed a first exothermic effect in the temperature range of 150 - 300 °C with an averaged energy release of -210 J/g and a second exothermic effect the range of 400 to >500 °C with an averaged energy release of >-370 J/g. Based on these results the test item is regarded to be stable at room temperature and is considered to melt at approximately 50 to 60°C. In a study according to OECD test guideline 104 (2006) a preliminary test was performed in order to determine the melting behaviour of Compimide 183. Melting of the substance was optically determined. The substance began to melt at 56°C and was completely molten at 76°C. Taken together, the results of all three sutides indicate that the substance has a low melting point. The thermal stability test and the test for melting behavior revealed melting temperatures in the same order of magnitude and based on a Weight of Evidence approach, the melting point of the test item is considered to be 76°C.

In a study conducted according to OECD Test Guideline 103 (adopted 27 July, 1995) in order to determine the boiling point of Compimide 183, a thermogravimetric measurement and subsequently a differential scanning calorimetry (DSC) was performed. In the course of the thermogravimetric curve three steps were registered with maxima at 88 °C, 187 °C resp. 451 °C. A total mass loss of 46.7 % at the final temperature could be observed (mass change in the range until 110 °C: 0.9 %; mass change in the range from 110 to 280 °C: 3.2 %; mass change in the range from 280 to 600 °C: 42.1 %). Mass loss due to purging: 0.5%. During the DSC no sharp endothermic peak indicating a melting point could not be observed. In the range of approx. 35 °C there was an indication for a glass transition. Upon further heating the DSC-curve showed no endothermic peak. The course of the DSC-curve indicated decomposition starting at approx. 160 °C: Reweighing after the measurement showed that the sample had lost 6.7 %/ 7.1 % of its mass. Thus, Compimide 183 is considered to decompose but exhibits no melting or boiling point.

The relative density was determined in a study conducted according to OECD guideline 109 (2002) using a gas comparison pycnometer. The relative density was determined to be 1.32.

In a study conducted according to OECD guideline 104 (2006) the vapour pressure of Compimide 183 was determined using the Knudsen-cell. The vapour pressure at 20°C was extrapolated from measurements at temperatures of 61 - 86°C, thus it is considered to be 4.7E-6 Pa at 20°C.

There is no data about the partition coefficient of Compimide 183 available, however, as Compimide 183 is an organic UVCB substance and the constituents (oligomers) of the substance may behave different in physico‐chemical tests (and therefore, also in vivo) it is meaningful to derive Kow (logKow) values for each relevant constituent, thus, the partition coefficient of Compimide 183 was estimated using EPISuite/KOWWINv1.68 as a range of the values that possibly occur, taken into account every oligomer that may be present in the substance. For each oligomer (dimer, trimer, tetramer) in the reaction product of initial reaction products MDAB and ABH the partition coefficient was calculated, thus the logKow of Compimide is considered to be in the range of -1.6 to 1.2. The estimation is supposed to be reliable due to the molecular weight of the respective oligomers which is in the range for predictions with sufficient reliability and because the structural fragments are present in the training and validation dataset of the QSAR-model. However, also pentamers of MDAB and ABH can be formed but the prediction of the partition coefficient would be outside the applicability domain due to a molecular weight of > 1000 g/mol, hence the partition coefficients for pentamers were not established.

In a second prediction using ACD/Percepta and the GALAS methodology the partition coeffcients of all occurring oligomers (including pentamers) were calculated. This methodology compares the occurrence of certain structural fragments with training set substances that are structurally very similar to the test substance. The predictions were of sufficient reliability even for the high molecular weight oligomers since this methodology uses the Reliability Index which takes into account the similarity of the tested compound to the training set molecules and the consistence of experimental LogP values and baseline model prediction for the most similar compounds from the training set. Thus, only predictions with sufficient reliability were taken into account. The partition coefficient of Compimide is considered to be in the range of -2.22 and 0.27. Since the methodology used allows also the prediction of the high molecular weight oligomers with sufficient reliability the prediction is considered to provide representative and reliable results. Since the substance contains functional groups or structural elements that are considered to be ionogenic groups, the apparent partition coefficient for every possible oligomer formed by MDAB and ABH was calculated dependent on pH. The logD of Compimide 183 is considered to be in the range -0.32 and 2.22.

After calculation of the partition coefficient with three different methods the log Kow of Compimide 183 is between -0.32 and 2.22. This range covers all predicted log Kow values for the individual constituents and substantiate that Compimide 183 can be assumed to be a hydrophilic substance.

The water solubility was determined in a study conducted according to OECD guideline 105 (1995), using the column elution method, the water solubility is considered to be 28.3 mg/L at 20°C.

According to OECD guideline 115 (1995) the surface tension of a 90% saturated aqueous solution of the test item Compimide 183 was determined to be 56.33 mN/m (standard deviation ± 0.05 mN/m) at 20°C. Considering that distilled water has a surface tension of  72.75 mN/m at 20°C and the test item showed a surface tension below 60 mN/m under the conditions of this referring method, the test item should be regarded as being surface-active material.

In a test performed according to VDI 2263, sheet I, the self ignition temperature of Compimide 183 was determined using the Grewer Oven. No self ignition of the substance was observed because the item melted before ignition and is therefore not classified as self-heating substance in Division 4.2 “Substances liable to spontaneous combustion” (UN Transport Regulation) and EC 1272/2008 (CLP Regulation) Annex 1: 2.11. Furthermore, according to UN Test N.1 (2009) the test item could not be ignited nor smoldering occurred by treatment with a gas burner, thus, the test substance Compimide 183 has to be classified as ‘Not readily combustible solid of Division 4.1’ in the sense of the test guideline UN Test N.1 and does not need to be classified according to Regulation (EC) No 1272/2008 (CLP) and the Globally Harmonized System for Classification and Labelling of Chemicals (GHS) as flammable solid.

Based on its structure and on the determined physicochemical properties Compimide is regarded to be not oxidizing or explosive, thus testing of these end points was omitted. Similarily, no flash point was determined because the substance is a solid and flash point only refers to liquids. However, because the substance is marketed and handled only in a non-solid/granular form testing of the particle size was also omitted.