Synthesis of Novel Plasticizers Based on Poly(ε-caprolactone) and A Consideration of Their Influence on Nitroglycerine Migration in Double Base Solid Propellants

The presence of nitroglycerine (NG) in double base propellants and its subsequent migration from the propellant towards the inhibitor has always been an important issue. This problem may be considerably reduced by exploiting the concept of the introduction of electron donor sites to the propellant formulation. Plasticizers based on ε-caprolactone (ε-CL) were synthesized and characterized, and their activities for absorbing nitroglycerine were investigated. According to the results, the order of NG absorption is: PCL-(OH)2 < PCL-(OH)3< PCL-(OH)4< H-PCL. The observed differences in the properties of the plasticizers is discussed in terms of structural considerations. The data also showed that the hyperbranched poly(ε-caprolactone) (H-PCL) has the greatest effect in decreasing NG migration. Furthermore, the activity of these plasticizers in decreasing NG migration was also investigated by IR analysis.