MOLECULAR SIMULATION IN THE DESIGN OF PLASTICIZERS FOR HIGH PERFORMANCE, INSENSITIVE MUNITIONS AND ZERO POLLUTION

摘要

Research for a binder with high content of fillers, high energetic material performance, reduced sensitivity and vulnerability, and least significantly reduced environmental pollution has become a crucial challenge. Therefore, we have found a relatively simple approach in order to simulate the effect of an additive (called plasticizer) on the glass transition temperature of a polymer. This approach is a molecular design method, based on interaction energy calculations between an additive and a binder, with explicit atom description. The calculated energy is performed withGGenMol? software, it describes the non-bonded interactions (hydrogen bond, coulombic and van der Waals contributions) from a thermodynamic approach: a molecular mechanic calculation using a well set of parameters (specific force field) needed for energetic chemical groups. The interaction energy corresponds to the thermal energy brings to separate the plasticizer from the polymer below its glass transition temperature. This energy takes into account the molecular weight, the tridimensional structure and the intermolecular interactions, well known to influence the glass transition temperature of a polymer. Our methodology allows the design of a dedicated structure of a plasticiser which will decrease glass transition temperature of a polymer. Comparison with experimental data, obtained from differential scanning calorimetry, gives a good correlation. Introducing molecular descriptors, with a QSPR (Quantitative Structure Property Relationship) approach, improves the model. The best additive decreases the glass transition temperature of a PolyAdipateDiEthylenGlycol polymer (PADEG) to almost 10°C, with only 5% content.