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Prediction of Ignition Delay Times for Amine-based Liquid Propellants through a QSPR Approach

Zohari Narges, Pakdehi Shahram Ghanbari, Zarei Rohollah

Central European Journal of Energetic Materials

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2024

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Vol. 21, no. 1

68--79

EN

Decreasing the ignition delay time in the combustion chamber of a rocket engine is required from a safety point of view. However it takes a lot of time and money to find the most suitable compounds with a low ignition delay time. In the present research, a model is proposed to predict the ignition delay time of aminebased liquid propellants through the quantitative structure-property relationship (QSPR) method. This model was derived based on 35 data sets collected from reliable references and by the selection of appropriate descriptors using multivariate linear regression (MLR). The determination coefficient, mean absolute deviation and root mean square deviation of the new model were 0.9901, 2.51 and 3.19 ms, respectively, which indicates high reliability. Furthermore, the values of the cross validation coefficients of the new proposed model were Q²LOO = 0.9903 and Q²LMO = 0.9906, which confirm its sufficient validation. The most important variables which have an effect on the ignition delay time of amine-based liquid propellants were identified as the elemental composition, temperature and the percentage ratio of oxidizer to fuel (O/F).

2

Prediction of the Density of Energetic Co-crystals: a Way to Design High Performance Energetic Materials

Zohari Narges, Mohammadkhani Faezeh Ghiasvand

Central European Journal of Energetic Materials

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2020

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Vol. 17, no. 1

31--48

EN

For designing a new energetic material with good performance, a knowledge of its density is required. In this study, the relationship between the densities of energetic co-crystals and their molecular structures was examined through a quantitative structure-property relationship (QSPR) method. The methodology of this research provides a new model which can relate the density of an energetic co-crystal to several molecular structural descriptors, which are calculated by Dragon software. It is indicated that the density of a co-crystal is a function of sp, OB, DU, nAT, as well as several non-additive structural parameters. The new recommended correlation was derived on the basis of the experimental densities of 50 co-crystals with various structures as a training set. The R2 or determination coefficient of the derived correlation was 0.937. This correlation provided a suitable estimate for a further 12 energetic co-crystals as a test set. Meanwhile, the predictive ability of the correlation was investigated through a cross validation method. Moreover, the new model has more reliability and performance for predicting the densities of energetic co-crystals compared to a previous one which was based on an artificial neural network approach. As a matter of fact, designing novel energetic co-crystals is possible by utilising the proposed method.

3

Estimation of the Detonation Pressure of Co-crystal Explosives through a Novel, Simple and Reliable Model

Zohari Narges, Montazeri Mahnaz, Hosseini Seyed Ghorban

Central European Journal of Energetic Materials

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2020

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Vol. 17, no. 4

492--505

EN

The detonation properties of energetic co-crystals have a substantial role in the design of new co-crystals and it is necessary to know about them. In this study, a linear relationship is proposed between the detonation pressure of energetic co-crystals and their molecular structures via a quantitative structure property relationship (QSPR) method. This model assumes that the detonation pressure of an energetic co-crystal is a function of nN, Mw, nC/nH and nO/nH. The new model was obtained based on the calculated detonation pressures of 39 co-crystals as a training set. The R2 or determination coefficient of the acquired model was 0.9409. This novel correlation provided a proper assessment for a further 12 energetic co-crystals as a test set. Additionally, the root mean square and average absolute deviation of this newly presented correlation were found to be 2.249 and 1.716 GPa, respectively. As a consequence, the proposed correlation can also be utilized to design new energetic co-crystals.