Glass transition temperature determination of solid rocket propellants using various thermal analysis techniques

摘要

The paper presents results of experimental research of homogeneous and heterogeneous solid rocket propellants with special attention given to the determination of glass transition temperature. The homogeneous propellant PAC with density 1.58 g/cm~3 and heterogeneous propellant H2 with density 1.77 g/cm~3 were subjected to complex thermo-mechanical analysis with the use of DSC, DIL and DMA techniques. All experiments were conducted with the use of NETZSCH thermal analysers. Liquid nitrogen was used in order to achieve sub-zero temperature range in which the glass transition in solid rocket propellants occurs. Differential Scanning Calorimetry experiment was conducted with the use of DSC 404 F1 Pegasus with the heating rate of 10 K/min in the temperature range from -100 °C to 100 °C The glass transition of the propellants was determined on the basis of the specific heat change. Thermal expansion was measured with the use of DIL 402SU dilatometer in the temperature range from -100 °C to 110 °C. with the heating rates of 2 and 10 K/min. Dynamic mechanical analysis conducted in dual cantilever bending mode using the NETZSCH DMA 242C over temperature range from -110 °C to +120 °C, with the heating rate of 2 K/min and the frequency of 1 Hz. The glass transition was determined for both propellants from the peak of loss modulus curve. The results of conducted experiments for PAC and H2 solid rocket propellants can be useful in determining the temperature range of safe use and operation.