Thermal Hazards Studies for the Azidation Process in the Preparation of Tetra Functional Glycidylazide Polymer (t-GAP) Using a Thermal Screening Unit (TSU)

Glycidylazide polymer (GAP) tetraol or tetra functional GAP (t-GAP) is a potential energetic binder, capable of exhibiting superior mechanical properties and better curing behaviour for application in high energy propellants. t-GAP is conventionally prepared through azidation of tetra functional poly-epichlorohydrin (t-PECH). Azidation reactions using a metal azide are known to be sensitive to temperature. The present study was aimed at a systematic evaluation of the safe temperature limit for the preparation of t-GAP and to derive optimized reaction conditions using a thermal screening unit (TSU), through both dynamic and isothermal heating experiments. The thermal hazard studies suggested that the azidation reaction is fairly stable at temperatures above 100 °C as it did not exhibit any abrupt rise in reaction temperature or pressure. The process was validated using laboratory scale batches and completion of the reaction was verified using FTIR spectroscopy.