A brief overview on the effect of type and curing catalyst concentration and NCO / OH ratio on the pot life of the High energy composite based on hydroxyl terminated polybutadiene

The pot life of high-energy composites plays a decisive role in the ease of production process and the quality of the finished product's properties. Two effective parameters are the determination of the operating life of the curing agent concentration (NCO / OH ratio) and the amount of catalyst for curing. In this paper, the effect of different amounts of catalysts and different amounts of R (NCO / OH ratio) on the pot life of HTPB-based high energy composite has been studied from scientific sources. Investigations carried out in this study showed that increasing the amount of catalysts in the curing process increases the viscosity of the high energy composite. Also, increasing the amount of R from 0.8 to 1 speed increases the viscosity and increases the pot life of the application. It is interesting to note that with increasing R, from 1 to 1.1, the viscosity increase rate is higher than R=1 contrary to expectation and pot life increases. Energetic composite based on the IPDI curing agent has two distinct stages of increasing viscosity and two different speeds. This is attributed to the presence of two different reactive groups of isocyanates in the molecular structure of this curing agent. In this study, the effect of DBTDL, FeAA, TEB and TECH catalysts on the pot life of high energy composite based on HTPB has been compared and compared. Also, through the Kissinger and Ozawa equations, the amount of activation energy can be evaluated and compared in systems with a variety of catalysts. Based on this, DBTDL has the least amount of activation energy among the catalysts to be cured, resulting in a higher uptake of polyurethane curing times and a lower pot life. Also, according to the studies, to obtain suitable curing for polyurethane systems and proper pot life, the value of R is equal to 1.